diff rDiff/src/locfit/Source/liblocf.c @ 0:0f80a5141704

version 0.3 uploaded
author vipints
date Thu, 14 Feb 2013 23:38:36 -0500
parents
children
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rDiff/src/locfit/Source/liblocf.c	Thu Feb 14 23:38:36 2013 -0500
@@ -0,0 +1,4940 @@
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+
+#include "mex.h"
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *   Integration for hazard rate estimation. The functions in this
+ *   file are used to evaluate
+ *      sum int_0^{Ti} W_i(t,x) A()A()' exp( P() ) dt
+ *   for hazard rate models.
+ *
+ *   These routines assume the weight function is supported on [-1,1].
+ *   hasint_sph multiplies by exp(base(lf,i)), which allows estimating
+ *   the baseline in a proportional hazards model, when the covariate
+ *   effect base(lf,i) is known.
+ *
+ *   TODO:
+ *     hazint_sph, should be able to reduce mint in some cases with
+ *       small integration range. onedint could be used for beta-family
+ *       (RECT,EPAN,BISQ,TRWT) kernels.
+ *     hazint_prod, restrict terms from the sum based on x values.
+ *       I should count obs >= max, and only do that integration once.
+ */
+
+#include "locf.h"
+
+static double ilim[2*MXDIM], *ff, tmax;
+static lfdata *haz_lfd;
+static smpar  *haz_sp;
+
+/*
+ *  hrao returns 0 if integration region is empty.
+ *               1 otherwise.
+ */
+int haz_sph_int(dfx,cf,h,r1)
+double *dfx, *cf, h, *r1;
+{ double s, t0, t1, wt, th;
+  int j, dim, p;
+  s = 0; p = npar(haz_sp);
+  dim = haz_lfd->d;
+  for (j=1; j<dim; j++) s += SQR(dfx[j]/(h*haz_lfd->sca[j]));
+  if (s>1) return(0);
+
+  setzero(r1,p*p);
+  t1 = sqrt(1-s)*h*haz_lfd->sca[0];
+  t0 = -t1;
+  if (t0<ilim[0])   t0 = ilim[0];
+  if (t1>ilim[dim]) t1 = ilim[dim];
+  if (t1>dfx[0]) t1 = dfx[0];
+  if (t1<t0) return(0);
+
+/*  Numerical integration by Simpson's rule.
+ */
+  for (j=0; j<=de_mint; j++)
+  { dfx[0] = t0+(t1-t0)*j/de_mint;
+    wt = weight(haz_lfd, haz_sp, dfx, NULL, h, 0, 0.0);
+    fitfun(haz_lfd, haz_sp, dfx,NULL,ff,NULL);
+    th = innerprod(cf,ff,p);
+    if (link(haz_sp)==LLOG) th = exp(th);
+    wt *= 2+2*(j&1)-(j==0)-(j==de_mint);
+    addouter(r1,ff,ff,p,wt*th);
+  }
+  multmatscal(r1,(t1-t0)/(3*de_mint),p*p);
+
+  return(1);
+}
+
+int hazint_sph(t,resp,r1,cf,h)
+double *t, *resp, *r1, *cf, h;
+{ int i, j, n, p, st;
+  double dfx[MXDIM], eb, sb;
+  p = npar(haz_sp);
+  setzero(resp,p*p);
+  sb = 0.0;
+
+  n = haz_lfd->n;
+  for (i=0; i<=n; i++)
+  {
+    if (i==n)
+    { dfx[0] = tmax-t[0];
+      for (j=1; j<haz_lfd->d; j++) dfx[j] = 0.0;
+      eb = exp(sb/n);
+    }
+    else
+    { eb = exp(base(haz_lfd,i)); sb += base(haz_lfd,i);
+      for (j=0; j<haz_lfd->d; j++) dfx[j] = datum(haz_lfd,j,i)-t[j];
+    }
+
+    st = haz_sph_int(dfx,cf,h,r1);
+    if (st)
+      for (j=0; j<p*p; j++) resp[j] += eb*r1[j];
+  }
+  return(LF_OK);
+}
+
+int hazint_prod(t,resp,x,cf,h)
+double *t, *resp, *x, *cf, h;
+{ int d, p, i, j, k, st;
+  double dfx[MXDIM], t_prev,
+         hj, hs, ncf[MXDEG], ef, il1;
+  double prod_wk[MXDIM][2*MXDEG+1], eb, sb;
+
+  p = npar(haz_sp);
+  d = haz_lfd->d;
+  setzero(resp,p*p);
+  hj = hs = h*haz_lfd->sca[0];
+
+  ncf[0] = cf[0];
+  for (i=1; i<=deg(haz_sp); i++)
+  { ncf[i] = hj*cf[(i-1)*d+1]; hj *= hs;
+  }
+
+/*   for i=0..n....
+ *     First we compute prod_wk[j], j=0..d.
+ *     For j=0, this is int_0^T_i (u-t)^k W((u-t)/h) exp(b0*(u-t)) du
+ *     For remaining j,   (x(i,j)-x(j))^k Wj exp(bj*(x..-x.))
+ *
+ *     Second, we add to the integration (exp(a) incl. in integral)
+ *     with the right factorial denominators.
+ */
+  t_prev = ilim[0]; sb = 0.0;
+  for (i=0; i<=haz_lfd->n; i++)
+  { if (i==haz_lfd->n)
+    { dfx[0] = tmax-t[0];
+      for (j=1; j<d; j++) dfx[j] = 0.0;
+      eb = exp(sb/haz_lfd->n);
+    }
+    else
+    { eb = exp(base(haz_lfd,i)); sb += base(haz_lfd,i);
+      for (j=0; j<d; j++) dfx[j] = datum(haz_lfd,j,i)-t[j];
+    }
+
+    if (dfx[0]>ilim[0]) /* else it doesn't contribute */
+    {
+/* time integral */
+      il1 = (dfx[0]>ilim[d]) ? ilim[d] : dfx[0];
+      if (il1 != t_prev) /* don't repeat! */
+      { st = onedint(haz_sp,ncf,ilim[0]/hs,il1/hs,prod_wk[0]);
+        if (st>0) return(st);
+        hj = eb;
+        for (j=0; j<=2*deg(haz_sp); j++)
+        { hj *= hs;
+          prod_wk[0][j] *= hj;
+        }
+        t_prev = il1;
+      }
+
+/* covariate terms */
+      for (j=1; j<d; j++)
+      {
+        ef = 0.0;
+        for (k=deg(haz_sp); k>0; k--) ef = (ef+dfx[j])*cf[1+(k-1)*d+j];
+        ef = exp(ef);
+        prod_wk[j][0] = ef * W(dfx[j]/(h*haz_lfd->sca[j]),ker(haz_sp));
+        for (k=1; k<=2*deg(haz_sp); k++)
+          prod_wk[j][k] = prod_wk[j][k-1] * dfx[j];
+      }
+
+/*  add to the integration.  */
+      prodintresp(resp,prod_wk,d,deg(haz_sp),p);
+    } /* if dfx0 > ilim0 */
+  } /* n loop */
+
+/* symmetrize */
+  for (k=0; k<p; k++)
+    for (j=k; j<p; j++)
+      resp[j*p+k] = resp[k*p+j];
+  return(LF_OK);
+}
+
+int hazint(t,resp,resp1,cf,h)
+double *t, *resp, *resp1, *cf, h;
+{ if (haz_lfd->d==1) return(hazint_prod(t,resp,resp1,cf,h));
+  if (kt(haz_sp)==KPROD) return(hazint_prod(t,resp,resp1,cf,h));
+
+  return(hazint_sph(t,resp,resp1,cf,h));
+}
+
+void haz_init(lfd,des,sp,il)
+lfdata *lfd;
+design *des;
+smpar *sp;
+double *il;
+{ int i;
+  
+  haz_lfd = lfd;
+  haz_sp  = sp;
+
+  tmax = datum(lfd,0,0);
+  for (i=1; i<lfd->n; i++) tmax = MAX(tmax,datum(lfd,0,i));
+  ff = des->xtwx.wk;
+  for (i=0; i<2*lfd->d; i++) ilim[i] = il[i];
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *
+ *  Routines for one-dimensional numerical integration
+ *  in density estimation. The entry point is
+ *
+ *  onedint(cf,mi,l0,l1,resp)
+ *
+ *  which evaluates int W(u)u^j exp( P(u) ), j=0..2*deg.
+ *  P(u) = cf[0] + cf[1]u + cf[2]u^2/2 + ... + cf[deg]u^deg/deg!
+ *  l0 and l1 are the integration limits.
+ *  The results are returned through the vector resp.
+ *
+ */
+
+#include "locf.h"
+
+static int debug;
+
+int exbctay(b,c,n,z) /* n-term taylor series of e^(bx+cx^2) */
+double b, c, *z;
+int n;
+{ double ec[20];
+  int i, j;
+  z[0] = 1;
+  for (i=1; i<=n; i++) z[i] = z[i-1]*b/i;
+  if (c==0.0) return(n);
+  if (n>=40)
+  { WARN(("exbctay limit to n<40"));
+    n = 39;
+  }
+  ec[0] = 1;
+  for (i=1; 2*i<=n; i++) ec[i] = ec[i-1]*c/i;
+  for (i=n; i>1; i--)
+    for (j=1; 2*j<=i; j++)
+      z[i] += ec[j]*z[i-2*j];
+  return(n);
+}
+
+double explinjtay(l0,l1,j,cf)
+/* int_l0^l1 x^j e^(a+bx+cx^2); exbctay aroud l1 */
+double l0, l1, *cf;
+int j;
+{ double tc[40], f, s;
+  int k, n;
+  if ((l0!=0.0) | (l1!=1.0)) WARN(("explinjtay: invalid l0, l1"));
+  n = exbctay(cf[1]+2*cf[2]*l1,cf[2],20,tc);
+  s = tc[0]/(j+1);
+  f = 1/(j+1);
+  for (k=1; k<=n; k++)
+  { f *= -k/(j+k+1.0);
+    s += tc[k]*f;
+  }
+  return(f);
+}
+
+void explint1(l0,l1,cf,I,p) /* int x^j exp(a+bx); j=0..p-1 */
+double l0, l1, *cf, *I;
+int p;
+{ double y0, y1, f;
+  int j, k, k1;
+  y0 = mut_exp(cf[0]+l0*cf[1]);
+  y1 = mut_exp(cf[0]+l1*cf[1]);
+  if (p<2*fabs(cf[1])) k = p; else k = (int)fabs(cf[1]);
+
+  if (k>0)
+  { I[0] = (y1-y0)/cf[1];
+    for (j=1; j<k; j++) /* forward steps for small j */
+    { y1 *= l1; y0 *= l0;
+      I[j] = (y1-y0-j*I[j-1])/cf[1];
+    }
+    if (k==p) return;
+    y1 *= l1; y0 *= l0;
+  }
+
+  f = 1; k1 = k;
+  while ((k<50) && (f>1.0e-8)) /* initially Ik = diff(x^{k+1}e^{a+bx}) */
+  { y1 *= l1; y0 *= l0;
+    I[k] = y1-y0;
+    if (k>=p) f *= fabs(cf[1])/(k+1);
+    k++;
+  }
+  if (k==50) WARN(("explint1: want k>50"));
+  I[k] = 0.0;
+  for (j=k-1; j>=k1; j--) /* now do back step recursion */
+    I[j] = (I[j]-cf[1]*I[j+1])/(j+1);
+}
+
+void explintyl(l0,l1,cf,I,p) /* small c, use taylor series and explint1 */
+double l0, l1, *cf, *I;
+int p;
+{ int i;
+  double c;
+  explint1(l0,l1,cf,I,p+8);
+  c = cf[2];
+  for (i=0; i<p; i++)
+    I[i] = (((I[i+8]*c/4+I[i+6])*c/3+I[i+4])*c/2+I[i+2])*c+I[i];
+}
+
+void solvetrid(X,y,m)
+double *X, *y;
+int m;
+{ int i;
+  double s;
+  for (i=1; i<m; i++)
+  { s = X[3*i]/X[3*i-2];
+    X[3*i] = 0; X[3*i+1] -= s*X[3*i-1];
+    y[i] -= s*y[i-1];
+  }
+  for (i=m-2; i>=0; i--)
+  { s = X[3*i+2]/X[3*i+4];
+    X[3*i+2] = 0;
+    y[i] -= s*y[i+1];
+  }
+  for (i=0; i<m; i++) y[i] /= X[3*i+1];
+}
+
+void initi0i1(I,cf,y0,y1,l0,l1)
+double *I, *cf, y0, y1, l0, l1;
+{ double a0, a1, c, d, bi;
+  d = -cf[1]/(2*cf[2]); c = sqrt(2*fabs(cf[2]));
+  a0 = c*(l0-d); a1 = c*(l1-d);
+  if (cf[2]<0)
+  { bi = mut_exp(cf[0]+cf[1]*d+cf[2]*d*d)/c;
+    if (a0>0)
+    { if (a0>6) I[0] = (y0*ptail(-a0)-y1*ptail(-a1))/c;
+      else I[0] = S2PI*(mut_pnorm(-a0)-mut_pnorm(-a1))*bi;
+    }
+    else
+    { if (a1< -6) I[0] = (y1*ptail(a1)-y0*ptail(a0))/c;
+      else I[0] = S2PI*(mut_pnorm(a1)-mut_pnorm(a0))*bi;
+    }
+  }
+  else
+    I[0] = (y1*mut_daws(a1)-y0*mut_daws(a0))/c;
+  I[1] = (y1-y0)/(2*cf[2])+d*I[0];
+}
+
+void explinsid(l0,l1,cf,I,p) /* large b; don't use fwd recursion */
+double l0, l1, *cf, *I;
+int p;
+{ int k, k0, k1, k2;
+  double y0, y1, Z[150];
+if (debug) mut_printf("side: %8.5f %8.5f %8.5f    limt %8.5f %8.5f  p %2d\n",cf[0],cf[1],cf[2],l0,l1,p);
+ 
+  k0 = 2;
+  k1 = (int)(fabs(cf[1])+fabs(2*cf[2]));
+  if (k1<2) k1 = 2;
+  if (k1>p+20) k1 = p+20;
+  k2 = p+20;
+
+if (k2>50) { mut_printf("onedint: k2 warning\n"); k2 = 50; }
+  if (debug) mut_printf("k0 %2d  k1 %2d  k2 %2d  p %2d\n",k0,k1,k2,p);
+
+  y0 = mut_exp(cf[0]+l0*(cf[1]+l0*cf[2]));
+  y1 = mut_exp(cf[0]+l1*(cf[1]+l1*cf[2]));
+  initi0i1(I,cf,y0,y1,l0,l1);
+if (debug) mut_printf("i0 %8.5f  i1 %8.5f\n",I[0],I[1]);
+
+  y1 *= l1; y0 *= l0; /* should be x^(k1)*exp(..) */
+  if (k0<k1) /* center steps; initially x^k*exp(...) */
+    for (k=k0; k<k1; k++)
+    { y1 *= l1; y0 *= l0;
+      I[k] = y1-y0;
+      Z[3*k] = k; Z[3*k+1] = cf[1]; Z[3*k+2] = 2*cf[2];
+    }
+   
+  y1 *= l1; y0 *= l0; /* should be x^(k1)*exp(..) */
+if (debug) mut_printf("k1 %2d  y0 %8.5f  y1 %8.5f\n",k1,y0,y1);
+  for (k=k1; k<k2; k++)
+  { y1 *= l1; y0 *= l0;
+    I[k] = y1-y0;
+  }
+  I[k2] = I[k2+1] = 0.0;
+  for (k=k2-1; k>=k1; k--)
+    I[k] = (I[k]-cf[1]*I[k+1]-2*cf[2]*I[k+2])/(k+1);
+
+  if (k0<k1)
+  { I[k0] -= k0*I[k0-1];
+    I[k1-1] -= 2*cf[2]*I[k1];
+    Z[3*k0] = Z[3*k1-1] = 0;
+    solvetrid(&Z[3*k0],&I[k0],k1-k0);
+  }
+if (debug)
+{ mut_printf("explinsid:\n");
+  for (k=0; k<p; k++) mut_printf("  %8.5f\n",I[k]);
+}
+}
+
+void explinbkr(l0,l1,cf,I,p) /* small b,c; use back recursion */
+double l0, l1, *cf, *I;
+int p;
+{ int k, km;
+  double y0, y1;
+  y0 = mut_exp(cf[0]+l0*(cf[1]+cf[2]*l0));
+  y1 = mut_exp(cf[0]+l1*(cf[1]+cf[2]*l1));
+  km = p+10;
+  for (k=0; k<=km; k++)
+  { y1 *= l1; y0 *= l0;
+    I[k] = y1-y0;
+  }
+  I[km+1] = I[km+2] = 0;
+  for (k=km; k>=0; k--)
+    I[k] = (I[k]-cf[1]*I[k+1]-2*cf[2]*I[k+2])/(k+1);
+}
+
+void explinfbk0(l0,l1,cf,I,p) /* fwd and bac recur; b=0; c<0 */
+double l0, l1, *cf, *I;
+int p;
+{ double y0, y1, f1, f2, f, ml2;
+  int k, ks;
+
+  y0 = mut_exp(cf[0]+l0*l0*cf[2]);
+  y1 = mut_exp(cf[0]+l1*l1*cf[2]);
+  initi0i1(I,cf,y0,y1,l0,l1);
+
+  ml2 = MAX(l0*l0,l1*l1);
+  ks = 1+(int)(2*fabs(cf[2])*ml2);
+  if (ks<2) ks = 2;
+  if (ks>p-3) ks = p;
+
+  /* forward recursion for k < ks */
+  for (k=2; k<ks; k++)
+  { y1 *= l1; y0 *= l0;
+    I[k] = (y1-y0-(k-1)*I[k-2])/(2*cf[2]);
+  }
+  if (ks==p) return;
+
+  y1 *= l1*l1; y0 *= l0*l0;
+  for (k=ks; k<p; k++) /* set I[k] = x^{k+1}e^(a+cx^2) | {l0,l1} */
+  { y1 *= l1; y0 *= l0;
+    I[k] = y1-y0;
+  }
+
+  /* initialize I[p-2] and I[p-1] */
+  f1 = 1.0/p; f2 = 1.0/(p-1);
+  I[p-1] *= f1; I[p-2] *= f2;
+  k = p; f = 1.0;
+  while (f>1.0e-8)
+  { y1 *= l1; y0 *= l0;
+    if ((k-p)%2==0) /* add to I[p-2] */
+    { f2 *= -2*cf[2]/(k+1);
+      I[p-2] += (y1-y0)*f2;
+    }
+    else /* add to I[p-1] */
+    { f1 *= -2*cf[2]/(k+1);
+      I[p-1] += (y1-y0)*f1;
+      f *= 2*fabs(cf[2])*ml2/(k+1);
+    }
+    k++;
+  }
+  
+  /* use back recursion for I[ks..(p-3)] */
+  for (k=p-3; k>=ks; k--)
+    I[k] = (I[k]-2*cf[2]*I[k+2])/(k+1);
+}
+
+void explinfbk(l0,l1,cf,I,p) /* fwd and bac recur; b not too large */
+double l0, l1, *cf, *I;
+int p;
+{ double y0, y1;
+  int k, ks, km;
+
+  y0 = mut_exp(cf[0]+l0*(cf[1]+l0*cf[2]));
+  y1 = mut_exp(cf[0]+l1*(cf[1]+l1*cf[2]));
+  initi0i1(I,cf,y0,y1,l0,l1);
+
+  ks = (int)(3*fabs(cf[2]));
+  if (ks<3) ks = 3;
+  if (ks>0.75*p) ks = p; /* stretch the forward recurs as far as poss. */
+  /* forward recursion for k < ks */
+  for (k=2; k<ks; k++)
+  { y1 *= l1; y0 *= l0;
+    I[k] = (y1-y0-cf[1]*I[k-1]-(k-1)*I[k-2])/(2*cf[2]);
+  }
+  if (ks==p) return;
+
+  km = p+15;
+  y1 *= l1*l1; y0 *= l0*l0;
+  for (k=ks; k<=km; k++)
+  { y1 *= l1; y0 *= l0;
+    I[k] = y1-y0;
+  }
+  I[km+1] = I[km+2] = 0.0;
+  for (k=km; k>=ks; k--)
+    I[k] = (I[k]-cf[1]*I[k+1]-2*cf[2]*I[k+2])/(k+1);
+}
+
+void recent(I,resp,wt,p,s,x)
+double *I, *resp, *wt, x;
+int p, s;
+{ int i, j;
+
+  /* first, use W taylor series I -> resp */
+  for (i=0; i<=p; i++)
+  { resp[i] = 0.0;
+    for (j=0; j<s; j++) resp[i] += wt[j]*I[i+j];
+  }
+
+  /* now, recenter x -> 0 */
+  if (x==0) return;
+  for (j=0; j<=p; j++) for (i=p; i>j; i--) resp[i] += x*resp[i-1];
+}
+
+void recurint(l0,l2,cf,resp,p,ker)
+double l0, l2, *cf, *resp;
+int p, ker;
+{ int i, s;
+  double l1, d0, d1, d2, dl, z0, z1, z2, wt[20], ncf[3], I[50], r1[5], r2[5];
+if (debug) mut_printf("\nrecurint: %8.5f %8.5f %8.5f   %8.5f %8.5f\n",cf[0],cf[1],cf[2],l0,l2);
+
+  if (cf[2]==0) /* go straight to explint1 */
+  { s = wtaylor(wt,0.0,ker);
+if (debug) mut_printf("case 1\n");
+    explint1(l0,l2,cf,I,p+s);
+    recent(I,resp,wt,p,s,0.0);
+    return;
+  }
+
+  dl = l2-l0;
+  d0 = cf[1]+2*l0*cf[2];
+  d2 = cf[1]+2*l2*cf[2];
+  z0 = cf[0]+l0*(cf[1]+l0*cf[2]);
+  z2 = cf[0]+l2*(cf[1]+l2*cf[2]);
+
+  if ((fabs(cf[1]*dl)<1) && (fabs(cf[2]*dl*dl)<1))
+  { ncf[0] = z0; ncf[1] = d0; ncf[2] = cf[2];
+if (debug) mut_printf("case 2\n");
+    s = wtaylor(wt,l0,ker);
+    explinbkr(0.0,dl,ncf,I,p+s);
+    recent(I,resp,wt,p,s,l0);
+    return;
+  }
+
+  if (fabs(cf[2]*dl*dl)<0.001) /* small c, use explint1+tay.ser */
+  { ncf[0] = z0; ncf[1] = d0; ncf[2] = cf[2];
+if (debug) mut_printf("case small c\n");
+    s = wtaylor(wt,l0,ker);
+    explintyl(0.0,l2-l0,ncf,I,p+s);
+    recent(I,resp,wt,p,s,l0);
+    return;
+  }
+
+  if (d0*d2<=0) /* max/min in [l0,l2] */
+  { l1 = -cf[1]/(2*cf[2]);
+    z1 = cf[0]+l1*(cf[1]+l1*cf[2]);
+    d1 = 0.0;
+    if (cf[2]<0) /* peak, integrate around l1 */
+    { s = wtaylor(wt,l1,ker);
+      ncf[0] = z1; ncf[1] = 0.0; ncf[2] = cf[2];
+if (debug) mut_printf("case peak  p %2d  s %2d\n",p,s);
+      explinfbk0(l0-l1,l2-l1,ncf,I,p+s);
+      recent(I,resp,wt,p,s,l1);
+      return;
+    }
+  }
+
+  if ((d0-2*cf[2]*dl)*(d2+2*cf[2]*dl)<0) /* max/min is close to [l0,l2] */
+  { l1 = -cf[1]/(2*cf[2]);
+    z1 = cf[0]+l1*(cf[1]+l1*cf[2]);
+    if (l1<l0) { l1 = l0; z1 = z0; }
+    if (l1>l2) { l1 = l2; z1 = z2; }
+
+    if ((z1>=z0) & (z1>=z2)) /* peak; integrate around l1 */
+    { s = wtaylor(wt,l1,ker);
+if (debug) mut_printf("case 4\n");
+      d1 = cf[1]+2*l1*cf[2];
+      ncf[0] = z1; ncf[1] = d1; ncf[2] = cf[2];
+      explinfbk(l0-l1,l2-l1,ncf,I,p+s);
+      recent(I,resp,wt,p,s,l1);
+      return;
+    }
+
+    /* trough; integrate [l0,l1] and [l1,l2] */
+    for (i=0; i<=p; i++) r1[i] = r2[i] = 0.0;
+    if (l0<l1)
+    { s = wtaylor(wt,l0,ker);
+if (debug) mut_printf("case 5\n");
+      ncf[0] = z0; ncf[1] = d0; ncf[2] = cf[2];
+      explinfbk(0.0,l1-l0,ncf,I,p+s);
+      recent(I,r1,wt,p,s,l0);
+    }
+    if (l1<l2)
+    { s = wtaylor(wt,l2,ker);
+if (debug) mut_printf("case 6\n");
+      ncf[0] = z2; ncf[1] = d2; ncf[2] = cf[2];
+      explinfbk(l1-l2,0.0,ncf,I,p+s);
+      recent(I,r2,wt,p,s,l2);
+    }
+    for (i=0; i<=p; i++) resp[i] = r1[i]+r2[i];
+    return;
+  }
+
+  /* Now, quadratic is monotone on [l0,l2]; big b; moderate c */
+  if (z2>z0+3) /* steep increase, expand around l2 */
+  { s = wtaylor(wt,l2,ker);
+if (debug) mut_printf("case 7\n");
+
+
+    ncf[0] = z2; ncf[1] = d2; ncf[2] = cf[2];
+    explinsid(l0-l2,0.0,ncf,I,p+s);
+    recent(I,resp,wt,p,s,l2);
+if (debug) mut_printf("7 resp: %8.5f %8.5f %8.5f %8.5f\n",resp[0],resp[1],resp[2],resp[3]);
+    return;
+  }
+
+  /* bias towards expansion around l0, because it's often 0 */
+if (debug) mut_printf("case 8\n");
+  s = wtaylor(wt,l0,ker);
+  ncf[0] = z0; ncf[1] = d0; ncf[2] = cf[2];
+  explinsid(0.0,l2-l0,ncf,I,p+s);
+  recent(I,resp,wt,p,s,l0);
+  return;
+}
+
+int onedexpl(cf,deg,resp)
+double *cf, *resp;
+int deg;
+{ int i;
+  double f0, fr, fl;
+  if (deg>=2) LERR(("onedexpl only valid for deg=0,1"));
+  if (fabs(cf[1])>=EFACT) return(LF_BADP);
+
+  f0 = exp(cf[0]); fl = fr = 1.0;
+  for (i=0; i<=2*deg; i++)
+  { f0 *= i+1;
+    fl /=-(EFACT+cf[1]);
+    fr /=  EFACT-cf[1];
+    resp[i] = f0*(fr-fl);
+  }
+  return(LF_OK);
+}
+
+int onedgaus(cf,deg,resp)
+double *cf, *resp;
+int deg;
+{ int i;
+  double f0, mu, s2;
+  if (deg==3)
+  { LERR(("onedgaus only valid for deg=0,1,2"));
+    return(LF_ERR);
+  }
+  if (2*cf[2]>=GFACT*GFACT) return(LF_BADP);
+
+  s2 = 1/(GFACT*GFACT-2*cf[2]);
+  mu = cf[1]*s2;
+  resp[0] = 1.0;
+  if (deg>=1)
+  { resp[1] = mu;
+    resp[2] = s2+mu*mu;
+    if (deg==2)
+    { resp[3] = mu*(3*s2+mu*mu);
+      resp[4] = 3*s2*s2 + mu*mu*(6*s2+mu*mu);
+    }
+  }
+  f0 = S2PI * exp(cf[0]+mu*mu/(2*s2))*sqrt(s2);
+  for (i=0; i<=2*deg; i++) resp[i] *= f0;
+  return(LF_OK);
+}
+
+int onedint(sp,cf,l0,l1,resp) /* int W(u)u^j exp(..), j=0..2*deg */
+smpar *sp;
+double *cf, l0, l1, *resp;
+{ double u, uj, y, ncf[4], rr[5];
+  int i, j;
+
+if (debug) mut_printf("onedint: %f %f %f   %f %f\n",cf[0],cf[1],cf[2],l0,l1);
+
+  if (deg(sp)<=2)
+  { for (i=0; i<3; i++) ncf[i] = (i>deg(sp)) ? 0.0 : cf[i];
+    ncf[2] /= 2;
+
+    if (ker(sp)==WEXPL) return(onedexpl(ncf,deg(sp),resp));
+    if (ker(sp)==WGAUS) return(onedgaus(ncf,deg(sp),resp));
+
+    if (l1>0)
+      recurint(MAX(l0,0.0),l1,ncf,resp,2*deg(sp),ker(sp));
+    else for (i=0; i<=2*deg(sp); i++) resp[i] = 0;
+
+    if (l0<0)
+    { ncf[1] = -ncf[1];
+      l0 = -l0; l1 = -l1;
+      recurint(MAX(l1,0.0),l0,ncf,rr,2*deg(sp),ker(sp));
+    }
+    else for (i=0; i<=2*deg(sp); i++) rr[i] = 0.0;
+
+    for (i=0; i<=2*deg(sp); i++)
+      resp[i] += (i%2==0) ? rr[i] : -rr[i];
+
+    return(LF_OK);
+  }
+
+  /* For degree >= 3, we use Simpson's rule. */
+  for (j=0; j<=2*deg(sp); j++) resp[j] = 0.0;
+  for (i=0; i<=de_mint; i++)
+  { u = l0+(l1-l0)*i/de_mint;
+    y = cf[0]; uj = 1;
+    for (j=1; j<=deg(sp); j++)
+    { uj *= u;
+      y += cf[j]*uj/fact[j];
+    }
+    y = (4-2*(i%2==0)-(i==0)-(i==de_mint)) *
+          W(fabs(u),ker(sp))*exp(MIN(y,300.0));
+    for (j=0; j<=2*deg(sp); j++)
+    { resp[j] += y;
+      y *= u;
+    }
+  }
+  for (j=0; j<=2*deg(sp); j++) resp[j] = resp[j]*(l1-l0)/(3*de_mint);
+  return(LF_OK);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+extern int lf_status;
+static double u[MXDIM], ilim[2*MXDIM], *ff, hh, *cff;
+static lfdata *den_lfd;
+static design *den_des;
+static smpar *den_sp;
+int fact[] = {1, 1, 2, 6, 24, 120, 720, 5040, 40320, 362880, 3628800};
+int de_mint  = 20;
+int de_itype = IDEFA;
+int de_renorm= 0;
+
+int multint(), prodint(), gausint(), mlinint();
+
+#define NITYPE 7
+static char *itype[NITYPE] = { "default", "multi", "product", "mlinear",
+                          "hazard",  "sphere", "monte" };
+static int   ivals[NITYPE] =
+   { IDEFA, IMULT, IPROD, IMLIN, IHAZD, ISPHR, IMONT };
+int deitype(char *z)
+{ return(pmatch(z, itype, ivals, NITYPE, IDEFA));
+}
+
+void prresp(coef,resp,p)
+double *coef, *resp;
+int p;
+{ int i, j;
+  mut_printf("Coefficients:\n");
+  for (i=0; i<p; i++) mut_printf("%8.5f ",coef[i]);
+  mut_printf("\n");
+  mut_printf("Response matrix:\n");
+  for (i=0; i<p; i++)
+  { for (j=0; j<p; j++) mut_printf("%9.6f, ",resp[i+j*p]);
+    mut_printf("\n");
+  }
+}
+
+int mif(u,d,resp,M)
+double *u, *resp, *M;
+int d;
+{ double wt;
+  int i, j, p;
+
+  p = den_des->p;
+  wt = weight(den_lfd, den_sp, u, NULL, hh, 0, 0.0);
+  if (wt==0)
+  { setzero(resp,p*p);
+    return(p*p);
+  }
+
+  fitfun(den_lfd, den_sp, u,NULL,ff,NULL);
+  if (link(den_sp)==LLOG)
+    wt *= mut_exp(innerprod(ff,cff,p));
+  for (i=0; i<p; i++)
+    for (j=0; j<p; j++)
+      resp[i*p+j] = wt*ff[i]*ff[j];
+  return(p*p);
+}
+
+int multint(t,resp1,resp2,cf,h)
+double *t, *resp1, *resp2, *cf, h;
+{ int d, i, mg[MXDIM];
+
+  if (ker(den_sp)==WGAUS) return(gausint(t,resp1,resp2,cf,h,den_lfd->sca));
+
+  d = den_lfd->d;
+  for (i=0; i<d; i++) mg[i] = de_mint;
+
+  hh = h;
+  cff= cf;
+  simpsonm(mif,ilim,&ilim[d],d,resp1,mg,resp2);
+  return(LF_OK);
+}
+
+int mlinint(t,resp1,resp2,cf,h)
+double *t, *resp1, *resp2, *cf, h;
+{
+  double hd, nb, wt, wu, g[4], w0, w1, v, *sca;
+  int d, p, i, j, jmax, k, l, z, jj[2];
+
+  d = den_lfd->d; p = den_des->p; sca = den_lfd->sca;
+  hd = 1;
+  for (i=0; i<d; i++) hd *= h*sca[i];
+
+  if (link(den_sp)==LIDENT)
+  { setzero(resp1,p*p);
+    resp1[0] = wint(d,NULL,0,ker(den_sp))*hd;
+    if (deg(den_sp)==0) return(LF_OK);
+    jj[0] = 2; w0 = wint(d,jj,1,ker(den_sp))*hd*h*h;
+    for (i=0; i<d; i++) resp1[(i+1)*p+i+1] = w0*sca[i]*sca[i];
+    if (deg(den_sp)==1) return(LF_OK);
+    for (i=0; i<d; i++)
+    { j = p-(d-i)*(d-i+1)/2;
+      resp1[j] = resp1[p*j] = w0*sca[i]*sca[i]/2;
+    }
+    if (d>1)
+    { jj[1] = 2;
+      w0 = wint(d,jj,2,ker(den_sp)) * hd*h*h*h*h;
+    }
+    jj[0] = 4;
+    w1 = wint(d,jj,1,ker(den_sp)) * hd*h*h*h*h/4;
+    z = d+1;
+    for (i=0; i<d; i++)
+    { k = p-(d-i)*(d-i+1)/2;
+      for (j=i; j<d; j++)
+      { l = p-(d-j)*(d-j+1)/2;
+        if (i==j) resp1[z*p+z] = w1*SQR(sca[i])*SQR(sca[i]);
+        else
+        { resp1[z*p+z] = w0*SQR(sca[i])*SQR(sca[j]);
+          resp1[k*p+l] = resp1[k+p*l] = w0/4*SQR(sca[i])*SQR(sca[j]);
+        }
+        z++;
+    } }
+    return(LF_OK);
+  }
+  switch(deg(den_sp))
+  { case 0:
+      resp1[0] = mut_exp(cf[0])*wint(d,NULL,0,ker(den_sp))*hd;
+      return(LF_OK);
+    case 1:
+      nb = 0.0;
+      for (i=1; i<=d; i++)
+      { v = h*cf[i]*sca[i-1];
+        nb += v*v;
+      }
+      if (ker(den_sp)==WGAUS)
+      { w0 = 1/(GFACT*GFACT);
+        g[0] = mut_exp(cf[0]+w0*nb/2+d*log(S2PI/2.5));
+        g[1] = g[3] = g[0]*w0;
+        g[2] = g[0]*w0*w0;
+      }
+      else
+      { wt = wu = mut_exp(cf[0]);
+        w0 = wint(d,NULL,0,ker(den_sp)); g[0] = wt*w0;
+        g[1] = g[2] = g[3] = 0.0;
+        j = 0; jmax = (d+2)*de_mint;
+        while ((j<jmax) && (wt*w0/g[0]>1.0e-8))
+        { j++;
+          jj[0] = 2*j; w0 = wint(d,jj,1,ker(den_sp));
+          if (d==1) g[3] += wt * w0;
+          else
+          { jj[0] = 2; jj[1] = 2*j-2; w1 = wint(d,jj,2,ker(den_sp));
+            g[3] += wt*w1;
+            g[2] += wu*(w0-w1);
+          }
+          wt /= (2*j-1.0); g[1] += wt*w0;
+          wt *= nb/(2*j); g[0] += wt*w0;
+          wu /= (2*j-1.0)*(2*j);
+          if (j>1) wu *= nb;
+        }
+        if (j==jmax) WARN(("mlinint: series not converged"));
+      }
+      g[0] *= hd; g[1] *= hd;
+      g[2] *= hd; g[3] *= hd;
+      resp1[0] = g[0];
+      for (i=1; i<=d; i++)
+      { resp1[i] = resp1[(d+1)*i] = cf[i]*SQR(h*sca[i-1])*g[1];
+        for (j=1; j<=d; j++)
+        { resp1[(d+1)*i+j] = (i==j) ? g[3]*SQR(h*sca[i-1]) : 0;
+          resp1[(d+1)*i+j] += g[2]*SQR(h*h*sca[i-1]*sca[j-1])*cf[i]*cf[j];
+        }
+      }
+      return(LF_OK);
+  }
+  LERR(("mlinint: deg=0,1 only"));
+  return(LF_ERR);
+}
+
+void prodintresp(resp,prod_wk,dim,deg,p)
+double *resp, prod_wk[MXDIM][2*MXDEG+1];
+int dim, deg, p;
+{ double prod;
+  int i, j, k, j1, k1;
+
+  prod = 1.0;
+  for (i=0; i<dim; i++) prod *= prod_wk[i][0];
+  resp[0] += prod;
+  if (deg==0) return;
+
+  for (j1=1; j1<=deg; j1++)
+  { for (j=0; j<dim; j++)
+    { prod = 1.0;
+      for (i=0; i<dim; i++) prod *= prod_wk[i][j1*(j==i)];
+      prod /= fact[j1];
+      resp[1 + (j1-1)*dim +j] += prod;
+    }
+  }
+
+  for (k1=1; k1<=deg; k1++)
+    for (j1=k1; j1<=deg; j1++)
+    { for (k=0; k<dim; k++)
+        for (j=0; j<dim; j++)
+        { prod = 1.0;
+          for (i=0; i<dim; i++) prod *= prod_wk[i][k1*(k==i) + j1*(j==i)];
+          prod /= fact[k1]*fact[j1];
+          resp[ (1+(k1-1)*dim+k)*p + 1+(j1-1)*dim+j] += prod;
+        }
+    }
+}
+
+int prodint(t,resp,resp2,coef,h)
+double *t, *resp, *resp2, *coef, h;
+{ int dim, p, i, j, k, st;
+  double cf[MXDEG+1], hj, hs, prod_wk[MXDIM][2*MXDEG+1];
+
+  dim = den_lfd->d;
+  p = den_des->p;
+  for (i=0; i<p*p; i++) resp[i] = 0.0;
+  cf[0] = coef[0];
+
+/*  compute the one dimensional terms
+ */
+  for (i=0; i<dim; i++)
+  { hj = 1; hs = h*den_lfd->sca[i];
+    for (j=0; j<deg(den_sp); j++)
+    { hj *= hs;
+      cf[j+1] = hj*coef[ j*dim+i+1 ];
+    }
+    st = onedint(den_sp,cf,ilim[i]/hs,ilim[i+dim]/hs,prod_wk[i]);
+    if (st==LF_BADP) return(st);
+    hj = 1;
+    for (j=0; j<=2*deg(den_sp); j++)
+    { hj *= hs;
+      prod_wk[i][j] *= hj;
+    }
+    cf[0] = 0.0; /* so we only include it once, when d>=2 */
+  }
+
+/*  transfer to the resp array
+ */
+  prodintresp(resp,prod_wk,dim,deg(den_sp),p);
+
+/* Symmetrize.
+*/
+  for (k=0; k<p; k++)
+    for (j=k; j<p; j++)
+      resp[j*p+k] = resp[k*p+j];
+
+  return(st);
+}
+
+int gausint(t,resp,C,cf,h,sca)
+double *t, *resp, *C, *cf, h, *sca;
+{ double nb, det, z, *P;
+  int d, p, i, j, k, l, m1, m2, f;
+  d = den_lfd->d; p = den_des->p;
+  m1 = d+1; nb = 0;
+  P = &C[d*d];
+  resp[0] = 1;
+  for (i=0; i<d; i++)
+  { C[i*d+i] = SQR(GFACT/(h*sca[i]))-cf[m1++];
+    for (j=i+1; j<d; j++) C[i*d+j] = C[j*d+i] = -cf[m1++];
+  }
+  eig_dec(C,P,d);
+  det = 1;
+  for (i=1; i<=d; i++)
+  { det *= C[(i-1)*(d+1)];
+    if (det <= 0) return(LF_BADP);
+    resp[i] = cf[i];
+    for (j=1; j<=d; j++) resp[j+i*p] = 0;
+    resp[i+i*p] = 1;
+    svdsolve(&resp[i*p+1],u,P,C,P,d,0.0);
+  }
+  svdsolve(&resp[1],u,P,C,P,d,0.0);
+  det = sqrt(det);
+  for (i=1; i<=d; i++)
+  { nb += cf[i]*resp[i];
+    resp[i*p] = resp[i];
+    for (j=1; j<=d; j++)
+      resp[i+p*j] += resp[i]*resp[j];
+  }
+  m1 = d;
+  for (i=1; i<=d; i++)
+    for (j=i; j<=d; j++)
+    { m1++; f = 1+(i==j);
+      resp[m1] = resp[m1*p] = resp[i*p+j]/f;
+      m2 = d;
+      for (k=1; k<=d; k++)
+      { resp[m1+k*p] = resp[k+m1*p] =
+        ( resp[i]*resp[j*p+k] + resp[j]*resp[i*p+k]
+        + resp[k]*resp[i*p+j] - 2*resp[i]*resp[j]*resp[k] )/f;
+        for (l=k; l<=d; l++)
+        { m2++; f = (1+(i==j))*(1+(k==l));
+          resp[m1+m2*p] = resp[m2+m1*p] = ( resp[i+j*p]*resp[k+l*p]
+            + resp[i+k*p]*resp[j+l*p] + resp[i+l*p]*resp[j+k*p]
+            - 2*resp[i]*resp[j]*resp[k]*resp[l] )/f;
+    } } }
+  z = mut_exp(d*0.918938533+cf[0]+nb/2)/det;
+  multmatscal(resp,z,p*p);
+  return(LF_OK);
+}
+
+int likeden(coef, lk0, f1, A)
+double *coef, *lk0, *f1, *A;
+{ double lk, r;
+  int i, j, p, rstat;
+
+  lf_status = LF_OK;
+  p = den_des->p;
+  if ((link(den_sp)==LIDENT) && (coef[0] != 0.0)) return(NR_BREAK);
+  lf_status = (den_des->itype)(den_des->xev,A,den_des->xtwx.Q,coef,den_des->h);
+  if (lf_error) lf_status = LF_ERR;
+  if (lf_status==LF_BADP)
+  { *lk0 = -1.0e300;
+    return(NR_REDUCE);
+  }
+  if (lf_status!=LF_OK) return(NR_BREAK);
+  if (lf_debug>2) prresp(coef,A,p);
+
+  den_des->xtwx.p = p;
+  rstat = NR_OK;
+  switch(link(den_sp))
+  { case LLOG:
+      r = den_des->ss[0]/A[0];
+      coef[0] += log(r);
+      multmatscal(A,r,p*p);
+      A[0] = den_des->ss[0];
+      lk = -A[0];
+      if (fabs(coef[0]) > 700)
+      { lf_status = LF_OOB;
+        rstat = NR_REDUCE;
+      }
+      for (i=0; i<p; i++)
+      { lk += coef[i]*den_des->ss[i];
+        f1[i] = den_des->ss[i]-A[i];
+      }
+      break;
+    case LIDENT:
+      lk = 0.0;
+      for (i=0; i<p; i++)
+      { f1[i] = den_des->ss[i];
+        for (j=0; j<p; j++)
+          den_des->res[i] -= A[i*p+j]*coef[j];
+      }
+      break;
+  }
+  *lk0 = den_des->llk = lk;
+
+  return(rstat);
+}
+
+int inre(x,bound,d)
+double *x, *bound;
+int d;
+{ int i, z;
+  z = 1;
+  for (i=0; i<d; i++)
+    if (bound[i]<bound[i+d])
+      z &= (x[i]>=bound[i]) & (x[i]<=bound[i+d]);
+  return(z);
+}
+
+int setintlimits(lfd, x, h, ang, lset)
+lfdata *lfd;
+int *ang, *lset;
+double *x, h;
+{ int d, i;
+  d = lfd->d;
+  *ang = *lset = 0;
+  for (i=0; i<d; i++)
+  { if (lfd->sty[i]==STANGL)
+    { ilim[i+d] = ((h<2) ? 2*asin(h/2) : PI)*lfd->sca[i];
+      ilim[i] = -ilim[i+d];
+      *ang = 1;
+    }
+    else
+    { ilim[i+d] = h*lfd->sca[i];
+      ilim[i] = -ilim[i+d];
+
+      if (lfd->sty[i]==STLEFT) { ilim[i+d] = 0; *lset = 1; }
+      if (lfd->sty[i]==STRIGH) { ilim[i] = 0;   *lset = 1; }
+
+      if (lfd->xl[i]<lfd->xl[i+d]) /* user limits for this variable */
+      { if (lfd->xl[i]-x[i]> ilim[i])
+        { ilim[i] = lfd->xl[i]-x[i]; *lset=1; }
+        if (lfd->xl[i+d]-x[i]< ilim[i+d])
+        { ilim[i+d] = lfd->xl[i+d]-x[i]; *lset=1; }
+      }
+    }
+    if (ilim[i]==ilim[i+d]) return(LF_DEMP); /* empty integration */
+  }
+  return(LF_OK);
+}
+
+int selectintmeth(itype,lset,ang)
+int itype, lset, ang;
+{
+  if (itype==IDEFA) /* select the default method */
+  { if (fam(den_sp)==THAZ)
+    { if (ang) return(IDEFA);
+      return( IHAZD );
+    }
+
+    if (ubas(den_sp)) return(IMULT);
+
+    if (ang) return(IMULT);
+
+    if (iscompact(ker(den_sp)))
+    { if (kt(den_sp)==KPROD) return(IPROD);
+      if (lset)
+        return( (den_lfd->d==1) ? IPROD : IMULT );
+      if (deg(den_sp)<=1) return(IMLIN);
+      if (den_lfd->d==1) return(IPROD);
+      return(IMULT);
+    }
+
+    if (ker(den_sp)==WGAUS)
+    { if (lset) WARN(("Integration for Gaussian weights ignores limits"));
+      if ((den_lfd->d==1)|(kt(den_sp)==KPROD)) return(IPROD);
+      if (deg(den_sp)<=1) return(IMLIN);
+      if (deg(den_sp)==2) return(IMULT);
+    }
+
+    return(IDEFA);
+  }
+
+  /* user provided an integration method, check it is valid */
+
+  if (fam(den_sp)==THAZ)
+  { if (ang) return(INVLD);
+    if (!iscompact(ker(den_sp))) return(INVLD);
+    return( ((kt(den_sp)==KPROD) | (kt(den_sp)==KSPH)) ? IHAZD : INVLD );
+  }
+
+  if ((ang) && (itype != IMULT)) return(INVLD);
+
+  switch(itype)
+  { case IMULT:
+      if (ker(den_sp)==WGAUS) return(deg(den_sp)==2);
+      return( iscompact(ker(den_sp)) ? IMULT : INVLD );
+    case IPROD: return( ((den_lfd->d==1) | (kt(den_sp)==KPROD)) ? IPROD : INVLD );
+    case IMLIN: return( ((kt(den_sp)==KSPH) && (!lset) &&
+      (deg(den_sp)<=1)) ? IMLIN : INVLD );
+  }
+
+  return(INVLD);
+}
+
+extern double lf_tol;
+
+int densinit(lfd,des,sp)
+lfdata *lfd;
+design *des;
+smpar *sp;
+{ int p, i, ii, j, nnz, rnz, ang, lset, status;
+  double w, *cf;
+
+  den_lfd = lfd;
+  den_des = des;
+  den_sp  = sp;
+  cf = des->cf;
+
+  lf_tol = (link(sp)==LLOG) ? 1.0e-6 : 0.0;
+
+  p = des->p;
+  ff = des->xtwx.wk;
+  cf[0] = NOSLN;
+  for (i=1; i<p; i++) cf[i] = 0.0;
+
+  if (!inre(des->xev,lfd->xl,lfd->d)) return(LF_XOOR);
+
+  status = setintlimits(lfd,des->xev,des->h,&ang,&lset);
+  if (status != LF_OK) return(status);
+
+  switch(selectintmeth(de_itype,lset,ang))
+  { case IMULT: des->itype = multint; break;
+    case IPROD: des->itype = prodint; break;
+    case IMLIN: des->itype = mlinint; break;
+    case IHAZD: des->itype = hazint; break;
+    case INVLD: LERR(("Invalid integration method %d",de_itype));
+                break;
+    case IDEFA: LERR(("No integration type available for this model"));
+                break;
+    default: LERR(("densinit: unknown integral type"));
+  }
+
+  switch(deg(den_sp))
+  { case 0: rnz = 1; break;
+    case 1: rnz = 1; break;
+    case 2: rnz = lfd->d+1; break;
+    case 3: rnz = lfd->d+2; break;
+    default: LERR(("densinit: invalid degree %d",deg(den_sp)));
+  }
+  if (lf_error) return(LF_ERR);
+
+  setzero(des->ss,p);
+  nnz = 0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    if (!cens(lfd,ii))
+    { w = wght(des,ii)*prwt(lfd,ii);
+      for (j=0; j<p; j++) des->ss[j] += d_xij(des,ii,j)*w;
+      if (wght(des,ii)>0.00001) nnz++;
+  } }
+
+  if (fam(den_sp)==THAZ) haz_init(lfd,des,sp,ilim);
+/* this should really only be done once. Not sure how to enforce that,
+ * esp. when locfit() has been called directly.
+ */
+  if (fam(den_sp)==TDEN)
+    des->smwt = (lfd->w==NULL) ? lfd->n : vecsum(lfd->w,lfd->n);
+
+  if (lf_debug>2)
+  { mut_printf("    LHS: ");
+    for (i=0; i<p; i++) mut_printf(" %8.5f",des->ss[i]);
+    mut_printf("\n");
+  }
+
+  switch(link(den_sp))
+  { case LIDENT:
+      cf[0] = 0.0;
+      return(LF_OK);
+    case LLOG:
+      if (nnz<rnz) { cf[0] = -1000; return(LF_DNOP); }
+      cf[0] = 0.0;
+      return(LF_OK);
+    default:
+      LERR(("unknown link in densinit"));
+      return(LF_ERR);
+  }
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int bino_vallink(link)
+int link;
+{ return((link==LLOGIT) | (link==LIDENT) | (link==LASIN));
+}
+
+int bino_fam(y,p,th,link,res,cens,w)
+double y, p, th, *res, w;
+int link, cens;
+{ double wp;
+  if (link==LINIT)
+  { if (y<0) y = 0;
+    if (y>w) y = w;
+    res[ZDLL] = y;
+    return(LF_OK);
+  }
+  wp = w*p;
+  if (link==LIDENT)
+  { if ((p<=0) && (y>0)) return(LF_BADP);
+    if ((p>=1) && (y<w)) return(LF_BADP);
+    res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+    if (y>0)
+    { res[ZLIK] += y*log(wp/y);
+      res[ZDLL] += y/p;
+      res[ZDDLL]+= y/(p*p);
+    }
+    if (y<w)
+    { res[ZLIK] += (w-y)*log((w-wp)/(w-y));
+      res[ZDLL] -= (w-y)/(1-p);
+      res[ZDDLL]+= (w-y)/SQR(1-p);
+    }
+    return(LF_OK);
+  }
+  if (link==LLOGIT)
+  { if ((y<0) | (y>w)) /* goon observation; delete it */
+    { res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+      return(LF_OK);
+    }
+    res[ZLIK] = (th<0) ? th*y-w*log(1+exp(th)) : th*(y-w)-w*log(1+exp(-th));
+    if (y>0) res[ZLIK] -= y*log(y/w);
+    if (y<w) res[ZLIK] -= (w-y)*log(1-y/w);
+    res[ZDLL] = (y-wp);
+    res[ZDDLL]= wp*(1-p);
+    return(LF_OK);
+  }
+  if (link==LASIN)
+  { if ((p<=0) && (y>0)) return(LF_BADP);
+    if ((p>=1) && (y<w)) return(LF_BADP);
+    if ((th<0) | (th>PI/2)) return(LF_BADP);
+    res[ZDLL] = res[ZDDLL] = res[ZLIK] = 0;
+    if (y>0)
+    { res[ZDLL] += 2*y*sqrt((1-p)/p);
+      res[ZLIK] += y*log(wp/y);
+    }
+    if (y<w)
+    { res[ZDLL] -= 2*(w-y)*sqrt(p/(1-p));
+      res[ZLIK] += (w-y)*log((w-wp)/(w-y));
+    }
+    res[ZDDLL] = 4*w;
+    return(LF_OK);
+  }
+  LERR(("link %d invalid for binomial family",link));
+  return(LF_LNK);
+}
+
+int bino_check(sp,des,lfd)
+smpar *sp;
+design *des;
+lfdata *lfd;
+{ int i, ii;
+  double t0, t1;
+
+  if (fabs(des->cf[0])>700) return(LF_OOB);
+
+  /* check for separation.
+   * this won't detect separation if there's boundary points with
+   *   both 0 and 1 responses.
+   */
+  t0 = -1e100; t1 = 1e100;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    if ((resp(lfd,ii)<prwt(lfd,ii)) && (fitv(des,ii) > t0)) t0 = fitv(des,ii);
+    if ((resp(lfd,ii)>0) && (fitv(des,ii) < t1)) t1 = fitv(des,ii);
+    if (t1 <= t0) return(LF_OK);
+  }
+  mut_printf("separated %8.5f %8.5f\n",t0,t1);
+  return(LF_NSLN);
+}
+
+void setfbino(fam)
+family *fam;
+{ fam->deflink = LLOGIT;
+  fam->canlink = LLOGIT;
+  fam->vallink = bino_vallink;
+  fam->family  = bino_fam;
+  fam->pcheck  = bino_check;
+}
+
+int rbin_vallink(link)
+int link;
+{ return(link==LLOGIT);
+}
+
+int rbin_fam(y,p,th,link,res,cens,w)
+double y, p, th, *res, w;
+int link, cens;
+{ double s2y;
+  if (link==LINIT)
+  { res[ZDLL] = y;
+    return(LF_OK);
+  }
+  if ((y<0) | (y>w)) /* goon observation; delete it */
+  { res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+    return(LF_OK);
+  }
+  res[ZLIK] = (th<0) ? th*y-w*log(1+exp(th)) : th*(y-w)-w*log(1+exp(-th));
+  if (y>0) res[ZLIK] -= y*log(y/w);
+  if (y<w) res[ZLIK] -= (w-y)*log(1-y/w);
+  res[ZDLL] = (y-w*p);
+  res[ZDDLL]= w*p*(1-p);
+  if (-res[ZLIK]>HUBERC*HUBERC/2.0)
+  { s2y = sqrt(-2*res[ZLIK]);
+    res[ZLIK] = HUBERC*(HUBERC/2.0-s2y);
+    res[ZDLL] *= HUBERC/s2y;
+    res[ZDDLL] = HUBERC/s2y*(res[ZDDLL]-1/(s2y*s2y)*w*p*(1-p));
+  }
+  return(LF_OK);
+}
+
+void setfrbino(fam)
+family *fam;
+{ fam->deflink = LLOGIT;
+  fam->canlink = LLOGIT;
+  fam->vallink = rbin_vallink;
+  fam->family  = rbin_fam;
+  fam->pcheck  = bino_check;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int circ_vallink(link)
+int link;
+{ return(link==LIDENT);
+}
+
+int circ_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ if (link==LINIT)
+  { res[ZDLL] = w*sin(y);
+    res[ZLIK] = w*cos(y);
+    return(LF_OK);
+  }
+  res[ZDLL] = w*sin(y-mean);
+  res[ZDDLL]= w*cos(y-mean);
+  res[ZLIK] = res[ZDDLL]-w;
+  return(LF_OK);
+}
+
+extern double lf_tol;
+int circ_init(lfd,des,sp)
+lfdata *lfd;
+design *des;
+smpar *sp;
+{ int i, ii;
+  double s0, s1;
+  s0 = s1 = 0.0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    s0 += wght(des,ii)*prwt(lfd,ii)*sin(resp(lfd,ii)-base(lfd,ii));
+    s1 += wght(des,ii)*prwt(lfd,ii)*cos(resp(lfd,ii)-base(lfd,ii));
+  }
+  des->cf[0] = atan2(s0,s1);
+  for (i=1; i<des->p; i++) des->cf[i] = 0.0;
+  lf_tol = 1.0e-6;
+  return(LF_OK);
+}
+
+
+void setfcirc(fam)
+family *fam;
+{ fam->deflink = LIDENT;
+  fam->canlink = LIDENT;
+  fam->vallink = circ_vallink;
+  fam->family  = circ_fam;
+  fam->initial = circ_init;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int dens_vallink(link)
+int link;
+{ return((link==LIDENT) | (link==LLOG));
+}
+
+int dens_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ if (cens)
+    res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+  else
+  { res[ZLIK] = w*th;
+    res[ZDLL] = res[ZDDLL] = w;
+  }
+  return(LF_OK);
+}
+
+void setfdensity(fam)
+family *fam;
+{ fam->deflink = LLOG;
+  fam->canlink = LLOG;
+  fam->vallink = dens_vallink;
+  fam->family  = dens_fam;
+  fam->initial = densinit;
+  fam->like = likeden;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int gamma_vallink(link)
+int link;
+{ return((link==LIDENT) | (link==LLOG) | (link==LINVER));
+}
+
+int gamma_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double lb, pt, dg;
+  if (link==LINIT)
+  { res[ZDLL] = MAX(y,0.0);
+    return(LF_OK);
+  }
+  res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+  if (w==0.0) return(LF_OK);
+  if ((mean<=0) & (y>0)) return(LF_BADP);
+  if (link==LIDENT) lb = 1/th;
+  if (link==LINVER) lb = th;
+  if (link==LLOG)   lb = mut_exp(-th);
+  if (cens)
+  { if (y<=0) return(LF_OK);
+    pt = 1-igamma(lb*y,w);
+    dg = dgamma(lb*y,w,1.0,0);
+    res[ZLIK] = log(pt);
+    res[ZDLL] = -y*dg/pt;
+/*
+ * res[ZDLL]  = -y*dg/pt * dlb/dth.
+ * res[ZDDLL] =  y*dg/pt * (d2lb/dth2 + ((w-1)/lb-y)*(dlb/dth)^2)
+ *              + res[ZDLL]^2.
+ */
+    if (link==LLOG)       /* lambda = exp(-theta) */
+    { res[ZDLL] *= -lb;
+      res[ZDDLL] = dg*y*lb*(w-lb*y)/pt + SQR(res[ZDLL]);
+      return(LF_OK);
+    }
+    if (link==LINVER)     /* lambda = theta */
+    { res[ZDLL] *= 1.0;
+      res[ZDDLL] = dg*y*((w-1)*mean-y)/pt + SQR(res[ZDLL]);
+      return(LF_OK);
+    }
+    if (link==LIDENT)     /* lambda = 1/theta */
+    { res[ZDLL] *= -lb*lb;
+      res[ZDDLL] = dg*y*lb*lb*lb*(1+w-lb*y)/pt + SQR(res[ZDLL]);
+      return(LF_OK);
+    }
+  }
+  else
+  { if (y<0) WARN(("Negative Gamma observation"));
+    if (link==LLOG)
+    { res[ZLIK] = -lb*y+w*(1-th);
+      if (y>0) res[ZLIK] += w*log(y/w);
+      res[ZDLL] = lb*y-w;
+      res[ZDDLL]= lb*y;
+      return(LF_OK);
+    }
+    if (link==LINVER)
+    { res[ZLIK] = -lb*y+w-w*log(mean);
+      if (y>0) res[ZLIK] += w*log(y/w);
+      res[ZDLL] = -y+w*mean;
+      res[ZDDLL]= w*mean*mean;
+      return(LF_OK);
+    }
+    if (link==LIDENT)
+    { res[ZLIK] = -lb*y+w-w*log(mean);
+      if (y>0) res[ZLIK] += w*log(y/w);
+      res[ZDLL] = lb*lb*(y-w*mean);
+      res[ZDDLL]= lb*lb*lb*(2*y-w*mean);
+      return(LF_OK);
+    }
+  }
+  LERR(("link %d invalid for Gamma family",link));
+  return(LF_LNK);
+}
+
+void setfgamma(fam)
+family *fam;
+{ fam->deflink = LLOG;
+  fam->canlink = LINVER;
+  fam->vallink = gamma_vallink;
+  fam->family  = gamma_fam;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int gaus_vallink(link)
+int link;
+{ return((link==LIDENT) | (link==LLOG) | (link==LLOGIT));
+}
+
+int gaus_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double z, pz, dp;
+  if (link==LINIT)
+  { res[ZDLL] = w*y;
+    return(LF_OK);
+  }
+  z = y-mean;
+  if (cens)
+  { if (link!=LIDENT)
+    { LERR(("Link invalid for censored Gaussian family"));
+      return(LF_LNK);
+    }
+    pz = mut_pnorm(-z);
+    dp = ((z>6) ? ptail(-z) : exp(-z*z/2)/pz)/2.5066283;
+    res[ZLIK] = w*log(pz);
+    res[ZDLL] = w*dp;
+    res[ZDDLL]= w*dp*(dp-z);
+    return(LF_OK);
+  }
+  res[ZLIK] = -w*z*z/2; 
+  switch(link)
+  { case LIDENT:
+      res[ZDLL] = w*z;
+      res[ZDDLL]= w;
+      break;
+    case LLOG:
+      res[ZDLL] = w*z*mean;
+      res[ZDDLL]= w*mean*mean;
+      break;
+    case LLOGIT:
+      res[ZDLL] = w*z*mean*(1-mean);
+      res[ZDDLL]= w*mean*mean*(1-mean)*(1-mean);
+      break;
+    default:
+      LERR(("Invalid link for Gaussian family"));
+      return(LF_LNK);
+  }
+  return(LF_OK);
+}
+
+int gaus_check(sp,des,lfd)
+smpar *sp;
+design *des;
+lfdata *lfd;
+{ int i, ii;
+  if (fami(sp)->robust) return(LF_OK);
+  if (link(sp)==LIDENT)
+  { for (i=0; i<des->n; i++)
+    { ii = des->ind[i];
+      if (cens(lfd,ii)) return(LF_OK);
+    }
+    return(LF_DONE);
+  }
+  return(LF_OK);
+}
+
+void setfgauss(fam)
+family *fam;
+{ fam->deflink = LIDENT;
+  fam->canlink = LIDENT;
+  fam->vallink = gaus_vallink;
+  fam->family  = gaus_fam;
+  fam->pcheck  = gaus_check;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int geom_vallink(link)
+int link;
+{ return((link==LIDENT) | (link==LLOG));
+}
+
+int geom_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double p, pt, dp, p1;
+  if (link==LINIT)
+  { res[ZDLL] = MAX(y,0.0);
+    return(LF_OK);
+  }
+  p = 1/(1+mean);
+  if (cens) /* censored observation */
+  { if (y<=0)
+    { res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0;
+      return(LF_OK);
+    }
+    p1 = (link==LIDENT) ? -p*p : -p*(1-p);
+    pt = 1-ibeta(p,w,y);
+    dp = dbeta(p,w,y,0)/pt;
+    res[ZLIK] = log(pt);
+    res[ZDLL] = -dp*p1;
+    res[ZDDLL] = dp*dp*p1*p1;
+    if (link==LIDENT)
+      res[ZDDLL] += dp*p*p*p*(1+w*(1-p)-p*y)/(1-p);
+    else
+      res[ZDDLL] += dp*p*(1-p)*(w*(1-p)-p*y);
+    return(LF_OK);
+  }
+  else
+  { res[ZLIK] = (y+w)*log((y/w+1)/(mean+1));
+    if (y>0) res[ZLIK] += y*log(w*mean/y);
+    if (link==LLOG)
+    { res[ZDLL] = (y-w*mean)*p;
+      res[ZDDLL]= (y+w)*p*(1-p);
+      return(LF_OK);
+    }
+    if (link==LIDENT)
+    { res[ZDLL] = (y-w*mean)/(mean*(1+mean));
+      res[ZDDLL]= w/(mean*(1+mean));
+      return(LF_OK);
+    }
+  }
+  LERR(("link %d invalid for geometric family",link));
+  return(LF_LNK);
+}
+
+void setfgeom(fam)
+family *fam;
+{ fam->deflink = LLOG;
+  fam->canlink = LIDENT; /* this isn't correct. I haven't prog. canon */
+  fam->vallink = geom_vallink;
+  fam->family  = geom_fam;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+#define HUBERC 2.0
+
+double links_rs;
+int inllmix=0;
+
+/*
+ * lffamily("name") converts family names into a numeric value.
+ * typical usage is  fam(&lf->sp) = lffamily("gaussian");
+ * Note that family can be preceded by q and/or r for quasi, robust.
+ *
+ * link(&lf->sp) = lflink("log") does the same for the link function.
+ */
+#define NFAMILY 18
+static char *famil[NFAMILY] =
+  { "density", "ate",   "hazard",    "gaussian", "binomial",
+    "poisson", "gamma", "geometric", "circular", "obust", "huber",
+    "weibull", "cauchy","probab",    "logistic", "nbinomial",
+    "vonmises", "quant" };
+static int   fvals[NFAMILY] =
+  { TDEN,  TRAT,  THAZ,  TGAUS, TLOGT,
+    TPOIS, TGAMM, TGEOM, TCIRC, TROBT, TROBT,
+    TWEIB, TCAUC, TPROB, TLOGT, TGEOM, TCIRC, TQUANT };
+int lffamily(z)
+char *z;
+{ int quasi, robu, f;
+  quasi = robu = 0;
+  while ((z[0]=='q') | (z[0]=='r'))
+  { quasi |= (z[0]=='q');
+    robu  |= (z[0]=='r');
+    z++;
+  }
+  z[0] = tolower(z[0]);
+  f = pmatch(z,famil,fvals,NFAMILY,-1);
+  if ((z[0]=='o') | (z[0]=='a')) robu = 0;
+  if (f==-1)
+  { WARN(("unknown family %s",z));
+    f = TGAUS;
+  }
+  if (quasi) f += 64;
+  if (robu)  f += 128;
+  return(f);
+}
+
+#define NLINKS 8
+static char *ltype[NLINKS] = { "default", "canonical", "identity", "log",
+                          "logi",    "inverse",   "sqrt",     "arcsin" };
+static int   lvals[NLINKS] = { LDEFAU, LCANON, LIDENT, LLOG,
+                          LLOGIT, LINVER, LSQRT,  LASIN };
+int lflink(char *z)
+{ int f;
+  if (z==NULL) return(LDEFAU);
+  z[0] = tolower(z[0]);
+  f = pmatch(z, ltype, lvals, NLINKS, -1);
+  if (f==-1)
+  { WARN(("unknown link %s",z));
+    f = LDEFAU;
+  }
+  return(f);
+}
+
+int defaultlink(link,fam)
+int link;
+family *fam;
+{ if (link==LDEFAU) return(fam->deflink);
+  if (link==LCANON) return(fam->canlink);
+  return(link);
+}
+
+/*
+void robustify(res,rs)
+double *res, rs;
+{ double sc, z;
+  sc = rs*HUBERC;
+  if (res[ZLIK] > -sc*sc/2) return;
+  z = sqrt(-2*res[ZLIK]);
+  res[ZDDLL]= -sc*res[ZDLL]*res[ZDLL]/(z*z*z)+sc*res[ZDDLL]/z;
+  res[ZDLL]*= sc/z;
+  res[ZLIK] = sc*sc/2-sc*z;
+}
+*/
+void robustify(res,rs)
+double *res, rs;
+{ double sc, z;
+  sc = rs*HUBERC;
+  if (res[ZLIK] > -sc*sc/2)
+  { res[ZLIK] /= sc*sc;
+    res[ZDLL] /= sc*sc;
+    res[ZDDLL] /= sc*sc;
+    return;
+  }
+  z = sqrt(-2*res[ZLIK]);
+  res[ZDDLL]= (-sc*res[ZDLL]*res[ZDLL]/(z*z*z)+sc*res[ZDDLL]/z)/(sc*sc);
+  res[ZDLL]*= 1.0/(z*sc);
+  res[ZLIK] = 0.5-z/sc;
+}
+
+double lf_link(y,lin)
+double y;
+int lin;
+{ switch(lin)
+  { case LIDENT: return(y);
+    case LLOG:   return(log(y));
+    case LLOGIT: return(logit(y));
+    case LINVER: return(1/y);
+    case LSQRT:  return(sqrt(fabs(y)));
+    case LASIN:  return(asin(sqrt(y)));
+  }
+  LERR(("link: unknown link %d",lin));
+  return(0.0);
+}
+
+double invlink(th,lin)
+double th;
+int lin;
+{ switch(lin)
+  { case LIDENT: return(th);
+    case LLOG:   return(mut_exp(th));
+    case LLOGIT: return(expit(th));
+    case LINVER: return(1/th);
+    case LSQRT:  return(th*fabs(th));
+    case LASIN:  return(sin(th)*sin(th));
+    case LINIT:  return(0.0);
+  }
+  LERR(("invlink: unknown link %d",lin));
+  return(0.0);
+}
+
+/* the link and various related functions */
+int links(th,y,fam,link,res,c,w,rs)
+double th, y, *res, w, rs;
+int link, c;
+family *fam;
+{ double mean;
+  int st;
+
+  mean = res[ZMEAN] = invlink(th,link);
+  if (lf_error) return(LF_LNK);
+  links_rs = rs;
+/*  mut_printf("links: rs %8.5f\n",rs); */
+
+  st = fam->family(y,mean,th,link,res,c,w);
+
+  if (st!=LF_OK) return(st);
+  if (link==LINIT) return(st);
+  if (isrobust(fam)) robustify(res,rs);
+  return(st);
+}
+
+/*
+  stdlinks is a version of links when family, link, response e.t.c
+  all come from the standard places.
+*/
+int stdlinks(res,lfd,sp,i,th,rs)
+lfdata *lfd;
+smpar *sp;
+double th, rs, *res;
+int i;
+{
+  return(links(th,resp(lfd,i),fami(sp),link(sp),res,cens(lfd,i),prwt(lfd,i),rs));
+}
+
+/*
+ *  functions used in variance, skewness, kurtosis calculations
+ *  in scb corrections.
+ */
+
+double b2(th,tg,w)
+double th, w;
+int tg;
+{ double y;
+  switch(tg&63)
+  { case TGAUS: return(w);
+    case TPOIS: return(w*mut_exp(th));
+    case TLOGT:
+      y = expit(th);
+      return(w*y*(1-y));
+  }
+  LERR(("b2: invalid family %d",tg));
+  return(0.0);
+}
+
+double b3(th,tg,w)
+double th, w;
+int tg;
+{ double y;
+  switch(tg&63)
+  { case TGAUS: return(0.0);
+    case TPOIS: return(w*mut_exp(th));
+    case TLOGT:
+      y = expit(th);
+      return(w*y*(1-y)*(1-2*y));
+  }
+  LERR(("b3: invalid family %d",tg));
+  return(0.0);
+}
+
+double b4(th,tg,w)
+double th, w;
+int tg;
+{ double y;
+  switch(tg&63)
+  { case TGAUS: return(0.0);
+    case TPOIS: return(w*mut_exp(th));
+    case TLOGT:
+      y = expit(th); y = y*(1-y);
+      return(w*y*(1-6*y));
+  }
+  LERR(("b4: invalid family %d",tg));
+  return(0.0);
+}
+
+int def_check(sp,des,lfd)
+smpar *sp;
+design *des;
+lfdata *lfd;
+{ switch(link(sp))
+  { case LLOG: if (des->cf[0]>700) return(LF_OOB);
+               break;
+  }
+  return(LF_OK);
+}
+extern void setfdensity(), setfgauss(), setfbino(), setfpoisson();
+extern void setfgamma(), setfgeom(), setfcirc(), setfweibull();
+extern void setfrbino(), setfrobust(), setfcauchy(), setfquant();
+
+void setfamily(sp)
+smpar *sp;
+{ int tg, lnk;
+  family *f;
+
+  tg = fam(sp);
+  f = fami(sp);
+  f->quasi = tg&64;
+  f->robust = tg&128;
+  f->initial = reginit;
+  f->like = likereg;
+  f->pcheck = def_check;
+
+  switch(tg&63)
+  { case TDEN:
+    case THAZ:
+    case TRAT:	setfdensity(f); break;
+    case TGAUS: setfgauss(f); break;
+    case TLOGT: setfbino(f); break;
+    case TRBIN: setfrbino(f); break;
+    case TPROB:
+    case TPOIS: setfpoisson(f); break;
+    case TGAMM: setfgamma(f); break;
+    case TGEOM: setfgeom(f); break;
+    case TWEIB: setfweibull(f);
+    case TCIRC: setfcirc(f); break;
+    case TROBT: setfrobust(f); break;
+    case TCAUC: setfcauchy(f); break;
+    case TQUANT: setfquant(f); break;
+    default: LERR(("setfamily: unknown family %d",tg&63));
+             return;
+  }
+  
+  lnk = defaultlink(link(sp),f);
+  if (!f->vallink(lnk))
+  { WARN(("setfamily: invalid link %d - revert to default",link(sp)));
+    link(sp) = f->deflink;
+  }
+  else
+    link(sp) = lnk;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int pois_vallink(link)
+int link;
+{ return((link==LLOG) | (link==LIDENT) | (link==LSQRT));
+}
+
+int pois_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double wmu, pt, dp;
+  if (link==LINIT)
+  { res[ZDLL] = MAX(y,0.0);
+    return(LF_OK);
+  }
+  wmu = w*mean;
+  if (inllmix) y = w*y;
+  if (cens)
+  { if (y<=0)
+    { res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0.0;
+      return(LF_OK);
+    }
+    pt = igamma(wmu,y);
+    dp = dgamma(wmu,y,1.0,0)/pt;
+    res[ZLIK] = log(pt);
+/*
+ * res[ZDLL] = dp * w*dmu/dth
+ * res[ZDDLL]= -dp*(w*d2mu/dth2 + (y-1)/mu*(dmu/dth)^2) + res[ZDLL]^2
+ */
+    if (link==LLOG)
+    { res[ZDLL] = dp*wmu;
+      res[ZDDLL]= -dp*wmu*(y-wmu) + SQR(res[ZDLL]);
+      return(LF_OK);
+    }
+    if (link==LIDENT)
+    { res[ZDLL] = dp*w;
+      res[ZDDLL]= -dp*(y-1-wmu)*w/mean + SQR(res[ZDLL]);
+      return(LF_OK);
+    }
+    if (link==LSQRT)
+    { res[ZDLL] = dp*2*w*th;
+      res[ZDDLL]= -dp*w*(4*y-2-4*wmu) + SQR(res[ZDLL]);
+      return(LF_OK);
+  } }
+  if (link==LLOG)
+  { if (y<0) /* goon observation - delete it */
+    { res[ZLIK] = res[ZDLL] = res[ZDDLL] = 0;
+      return(LF_OK);
+    }
+    res[ZLIK] = res[ZDLL] = y-wmu;
+    if (y>0) res[ZLIK] += y*(th-log(y/w));
+    res[ZDDLL] = wmu;
+    return(LF_OK);
+  }
+  if (link==LIDENT)
+  { if ((mean<=0) && (y>0)) return(LF_BADP);
+    res[ZLIK] = y-wmu;
+    res[ZDLL] = -w;
+    res[ZDDLL] = 0;
+    if (y>0)
+    { res[ZLIK] += y*log(wmu/y);
+      res[ZDLL] += y/mean;
+      res[ZDDLL]= y/(mean*mean);
+    }
+    return(LF_OK);
+  }
+  if (link==LSQRT)
+  { if ((mean<=0) && (y>0)) return(LF_BADP);
+    res[ZLIK] = y-wmu;
+    res[ZDLL] = -2*w*th;
+    res[ZDDLL]= 2*w;
+    if (y>0)
+    { res[ZLIK] += y*log(wmu/y);
+      res[ZDLL] += 2*y/th;
+      res[ZDDLL]+= 2*y/mean;
+    }
+    return(LF_OK);
+  }
+  LERR(("link %d invalid for Poisson family",link));
+  return(LF_LNK);
+}
+
+void setfpoisson(fam)
+family *fam;
+{ fam->deflink = LLOG;
+  fam->canlink = LLOG;
+  fam->vallink = pois_vallink;
+  fam->family  = pois_fam;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+#define QTOL 1.0e-10
+extern int lf_status;
+static double q0;
+
+int quant_vallink(int link) { return(1); }
+
+int quant_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double z, p;
+  if (link==LINIT)
+  { res[ZDLL] = w*y;
+    return(LF_OK);
+  }
+p = 0.5; /* should be pen(sp) */
+  z = y-mean;
+  res[ZLIK] = (z<0) ? (w*z/p) : (-w*z/(1-p));
+  res[ZDLL] = (z<0) ? -w/p : w/(1-p);
+  res[ZDDLL]= w/(p*(1-p));
+  return(LF_OK);
+}
+
+int quant_check(sp,des,lfd)
+smpar *sp;
+design *des;
+lfdata *lfd;
+{ return(LF_DONE);
+}
+
+void setfquant(fam)
+family *fam;
+{ fam->deflink = LIDENT;
+  fam->canlink = LIDENT;
+  fam->vallink = quant_vallink;
+  fam->family  = quant_fam;
+  fam->pcheck  = quant_check;
+}
+
+/*
+ * cycling rule for choosing among ties.
+ */
+int tiecycle(ind,i0,i1,oi)
+int *ind, i0, i1, oi;
+{ int i, ii, im;
+  im = ind[i0];
+  for (i=i0+1; i<=i1; i++)
+  { ii = ind[i];
+    if (im<=oi)
+    { if ((ii<im) | (ii>oi)) im = ii;
+    }
+    else
+    { if ((ii<im) & (ii>oi)) im = ii;
+    }
+  }
+  return(im);
+}
+
+/*
+ * move coefficient vector cf, as far as possible, in direction dc.
+ */
+int movecoef(lfd,des,p,cf,dc,oi)
+lfdata *lfd;
+design *des;
+double p, *cf, *dc;
+int oi;
+{ int i, ii, im, i0, i1, j;
+  double *lb, *el, e, sp, sn, sw, sum1, sum2, tol1;
+
+  lb = des->th;
+  el = des->res;
+  sum1 = sum2 = 0.0;
+
+  sp = sn = sw = 0.0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    lb[ii] = innerprod(dc,d_xi(des,ii),des->p);
+    e = resp(lfd,ii) - innerprod(cf,d_xi(des,ii),des->p);
+    el[ii] = (fabs(lb[ii])<QTOL) ? 1e100 : e/lb[ii];
+    if (lb[ii]>0)
+      sp += prwt(lfd,ii)*wght(des,ii)*lb[ii];
+    else
+      sn -= prwt(lfd,ii)*wght(des,ii)*lb[ii];
+    sw += prwt(lfd,ii)*wght(des,ii);
+  }
+printf("sp %8.5f  sn %8.5f\n",sn,sp);
+/* if sn, sp are both zero, should return an LF_PF.
+ * but within numerical tolerance? what does it mean?
+ */
+  if (sn+sp <= QTOL*q0) { lf_status = LF_PF; return(0); }
+
+  sum1 = sp/(1-p) + sn/p;
+  tol1 = QTOL*(sp+sn);
+  mut_order(el,des->ind,0,des->n-1);
+
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    sum2 += prwt(lfd,ii)*wght(des,ii)*((lb[ii]>0) ? lb[ii]/p : -lb[ii]/(1-p) );
+    sum1 -= prwt(lfd,ii)*wght(des,ii)*((lb[ii]>0) ? lb[ii]/(1-p) : -lb[ii]/p );
+    if (sum1<=sum2+tol1)
+    {
+/* determine the range of ties [i0,i1]
+ *   el[ind[i0..i1]] = el[ind[i]].
+ *   if sum1==sum2, el[ind[i+1]]..el[ind[i1]]] = el[ind[i1]], else i1 = i.
+ */
+      i0 = i1 = i;
+      while ((i0>0) && (el[des->ind[i0-1]]==el[ii])) i0--;
+      while ((i1<des->n-1) && (el[des->ind[i1+1]]==el[ii])) i1++;
+      if (sum1>=sum2-tol1)
+        while ((i1<des->n-1) && (el[des->ind[i1+1]]==el[des->ind[i+1]])) i1++;
+
+      if (i0<i1) ii = tiecycle(des->ind,i0,i1,oi);
+      for (j=0; j<des->p; j++) cf[j] += el[ii]*dc[j];
+      return(ii);
+    }
+  }
+mut_printf("Big finddlt problem.\n");
+ii = des->ind[des->n-1];
+for (j=0; j<des->p; j++) cf[j] += el[ii]*dc[j];
+return(ii);
+}
+
+/*
+ * special version of movecoef for min/max.
+ */
+int movemin(lfd,des,f,cf,dc,oi)
+design *des;
+lfdata *lfd;
+double *cf, *dc, f;
+int oi;
+{ int i, ii, im, p, s, ssum;
+  double *lb, sum, lb0, lb1, z0, z1;
+
+  lb = des->th;
+  s = (f<=0.0) ? 1 : -1;
+
+/* first, determine whether move should be in positive or negative direction */
+  p = des->p;
+  sum = 0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    lb[ii] = innerprod(dc,d_xi(des,ii),des->p);
+    sum += prwt(lfd,ii)*wght(des,ii)*lb[ii];
+  }
+  if (fabs(sum) <= QTOL*q0)
+  { lf_status = LF_PF;
+    return(0);
+  }
+  ssum = (sum<=0.0) ? -1 : 1;
+  if (ssum != s)
+    for (i=0; i<p; i++) dc[i] = -dc[i];
+
+/* now, move positively. How far can we move? */
+  lb0 = 1.0e100; im = oi;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    lb[ii] = innerprod(dc,d_xi(des,ii),des->p); /* must recompute - signs! */
+    if (s*lb[ii]>QTOL) /* should have scale-free tolerance here */
+    { z0 = innerprod(cf,d_xi(des,ii),p);
+      lb1 = (resp(lfd,ii) - z0)/lb[ii];
+      if (lb1<lb0)
+      { if (fabs(lb1-lb0)<QTOL) /* cycle */
+        { if (im<=oi)
+          { if ((ii>oi) | (ii<im)) im = ii; }
+          else
+          { if ((ii>oi) & (ii<im)) im = ii; }
+        }
+        else
+        { im = ii; lb0 = lb1; }
+      }
+    }
+  }
+
+  for (i=0; i<p; i++) cf[i] = cf[i]+lb0*dc[i];
+  if (im==-1) lf_status = LF_PF;
+  return(im);
+}
+
+double qll(lfd,spr,des,cf)
+lfdata *lfd;
+smpar *spr;
+design *des;
+double *cf;
+{ int i, ii;
+  double th, sp, sn, p, e;
+
+  p = pen(spr);
+  sp = sn = 0.0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    th = innerprod(d_xi(des,ii),cf,des->p);
+    e = resp(lfd,ii)-th;
+    if (e<0) sn -= prwt(lfd,ii)*wght(des,ii)*e;
+    if (e>0) sp += prwt(lfd,ii)*wght(des,ii)*e;
+  }
+  if (p<=0.0) return((sn<QTOL) ? -sp : -1e300);
+  if (p>=1.0) return((sp<QTOL) ? -sn : -1e300);
+  return(-sp/(1-p)-sn/p);
+}
+
+/*
+ * running quantile smoother.
+ */
+void lfquantile(lfd,sp,des,maxit)
+lfdata *lfd;
+smpar *sp;
+design *des;
+int maxit;
+{ int i, ii, im, j, k, p, *ci, (*mover)();
+  double *cf, *db, *dc, *cm, f, q1, q2, l0;
+
+printf("in lfquantile\n");
+  f = pen(sp);
+  p = des->p;
+  cf = des->cf;
+  dc = des->oc;
+  db = des->ss;
+  setzero(cf,p);
+  setzero(dc,p);
+  cm = des->V;
+  setzero(cm,p*p);
+  ci = (int *)des->fix;
+
+  q1 = -qll(lfd,sp,des,cf);
+  if (q1==0.0) { lf_status = LF_PF; return; }
+  for (i=0; i<p; i++) cm[i*(p+1)] = 1;
+  mover = movecoef;
+  if ((f<=0.0) | (f>=1.0)) mover = movemin;
+
+  dc[0] = 1.0;
+  im = mover(lfd,des,f,cf,dc,-1);
+  if (lf_status != LF_OK) return;
+  ci[0] = im;
+printf("init const %2d\n",ci[0]);
+  q0 = -qll(lfd,sp,des,cf);
+  if (q0<QTOL*q1) { lf_status = LF_PF; return; }
+
+printf("loop 0\n"); fflush(stdout);
+  for (i=1; i<p; i++)
+  {
+printf("i %2d\n",i);
+    memcpy(&cm[(i-1)*p],d_xi(des,im),p*sizeof(double));
+    setzero(db,p);
+    db[i] = 1.0;
+    resproj(db,cm,dc,p,i);
+printf("call mover\n"); fflush(stdout);
+    im = mover(lfd,des,f,cf,dc,-1);
+    if (lf_status != LF_OK) return;
+printf("mover %2d\n",im); fflush(stdout);
+    ci[i] = im;
+  }
+printf("call qll\n"); fflush(stdout);
+  q1 = qll(lfd,sp,des,cf);
+
+printf("loop 1    %d %d %d %d\n",ci[0],ci[1],ci[2],ci[3]); fflush(stdout);
+  for (k=0; k<maxit; k++)
+  { for (i=0; i<p; i++)
+    { for (j=0; j<p; j++)
+        if (j!=i) memcpy(&cm[(j-(j>i))*p],d_xi(des,ci[j]),p*sizeof(double));
+      memcpy(db,d_xi(des,ci[i]),p*sizeof(double));
+      resproj(db,cm,dc,p,p-1);
+printf("call mover\n"); fflush(stdout);
+      im = mover(lfd,des,f,cf,dc,ci[i]);
+      if (lf_status != LF_OK) return;
+printf("mover %2d\n",im); fflush(stdout);
+      ci[i] = im;
+    }
+    q2 = qll(lfd,sp,des,cf);
+/*
+ * convergence: require no change -- reasonable, since discrete?
+ * remember we're maximizing, and q's are negative.
+ */
+     if (q2 <= q1) return;
+     q1 = q2;
+  }
+printf("loop 2\n");
+  mut_printf("Warning: lfquantile not converged.\n");
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+extern double links_rs;
+
+int robust_vallink(link)
+int link;
+{ return(link==LIDENT);
+}
+
+int robust_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double z, sw;
+  if (link==LINIT)
+  { res[ZDLL] = w*y;
+    return(LF_OK);
+  }
+  sw = (w==1.0) ? 1.0 : sqrt(w); /* don't want unnecess. sqrt! */
+  z = sw*(y-mean)/links_rs;
+  res[ZLIK] = (fabs(z)<HUBERC) ? -z*z/2 : HUBERC*(HUBERC/2.0-fabs(z));
+  if (z< -HUBERC)
+  { res[ZDLL] = -sw*HUBERC/links_rs;
+    res[ZDDLL]= 0.0;
+    return(LF_OK);
+  }
+  if (z> HUBERC)
+  { res[ZDLL] = sw*HUBERC/links_rs;
+    res[ZDDLL]= 0.0;
+    return(LF_OK);
+  }
+  res[ZDLL] =  sw*z/links_rs;
+  res[ZDDLL] = w/(links_rs*links_rs);
+  return(LF_OK);
+}
+
+int cauchy_fam(y,p,th,link,res,cens,w)
+double y, p, th, *res, w;
+int link, cens;
+{ double z;
+  if (link!=LIDENT)
+  { LERR(("Invalid link in famcauc"));
+    return(LF_LNK);
+  }
+  z = w*(y-th)/links_rs;
+  res[ZLIK] = -log(1+z*z);
+  res[ZDLL] = 2*w*z/(links_rs*(1+z*z));
+  res[ZDDLL] = 2*w*w*(1-z*z)/(links_rs*links_rs*(1+z*z)*(1+z*z));
+  return(LF_OK);
+}
+
+extern double lf_tol;
+int robust_init(lfd,des,sp)
+lfdata *lfd;
+design *des;
+smpar *sp;
+{ int i;
+  for (i=0; i<des->n; i++)
+  des->res[i] = resp(lfd,(int)des->ind[i]) - base(lfd,(int)des->ind[i]);
+  des->cf[0] = median(des->res,des->n);
+  for (i=1; i<des->p; i++) des->cf[i] = 0.0;
+  lf_tol = 1.0e-6;
+  return(LF_OK);
+}
+
+void setfrobust(fam)
+family *fam;
+{ fam->deflink = LIDENT;
+  fam->canlink = LIDENT;
+  fam->vallink = robust_vallink;
+  fam->family  = robust_fam;
+  fam->initial = robust_init;
+  fam->robust = 0;
+}
+
+void setfcauchy(fam)
+family *fam;
+{ fam->deflink = LIDENT;
+  fam->canlink = LIDENT;
+  fam->vallink = robust_vallink;
+  fam->family  = cauchy_fam;
+  fam->initial = robust_init;
+  fam->robust = 0;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int weibull_vallink(link)
+int link;
+{ return((link==LIDENT) | (link==LLOG) | (link==LLOGIT));
+}
+
+int weibull_fam(y,mean,th,link,res,cens,w)
+double y, mean, th, *res, w;
+int link, cens;
+{ double yy;
+  yy = pow(y,w);
+  if (link==LINIT)
+  { res[ZDLL] = MAX(yy,0.0);
+    return(LF_OK);
+  }
+  if (cens)
+  { res[ZLIK] = -yy/mean;
+    res[ZDLL] = res[ZDDLL] = yy/mean;
+    return(LF_OK);
+  }
+  res[ZLIK] = 1-yy/mean-th;
+  if (yy>0) res[ZLIK] += log(w*yy);
+  res[ZDLL] = -1+yy/mean;
+  res[ZDDLL]= yy/mean;
+  return(LF_OK);
+}
+
+void setfweibull(fam)
+family *fam;
+{ fam->deflink = LLOG;
+  fam->canlink = LLOG;
+  fam->vallink = weibull_vallink;
+  fam->family  = weibull_fam;
+  fam->robust = 0;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+  Functions implementing the adaptive bandwidth selection.
+  Will make the final call to nbhd() to set smoothing weights
+  for selected bandwidth, But will **not** make the
+  final call to locfit().
+*/
+
+#include "locf.h"
+
+static double hmin;
+
+#define NACRI 5
+static char *atype[NACRI] = { "none", "cp", "ici", "mindex", "ok" };
+static int   avals[NACRI] = { ANONE, ACP, AKAT, AMDI, AOK };
+int lfacri(char *z)
+{ return(pmatch(z, atype, avals, NACRI, ANONE));
+}
+
+double adcri(lk,t0,t2,pen)
+double lk, t0, t2, pen;
+{ double y;
+/* return(-2*lk/(t0*exp(pen*log(1-t2/t0)))); */
+  /* return((-2*lk+pen*t2)/t0); */
+  y = (MAX(-2*lk,t0-t2)+pen*t2)/t0;
+  return(y);
+}
+
+double mmse(lfd,sp,dv,des)
+lfdata *lfd;
+smpar *sp;
+deriv *dv;
+design *des;
+{ int i, ii, j, p, p1;
+  double sv, sb, *l, dp;
+
+  l = des->wd;
+  wdiag(lfd, sp, des,l,dv,0,1,0);
+  sv = sb = 0;
+  p = npar(sp);
+  for (i=0; i<des->n; i++)
+  { sv += l[i]*l[i];
+    ii = des->ind[i];
+    dp = dist(des,ii);
+    for (j=0; j<deg(sp); j++) dp *= dist(des,ii);
+    sb += fabs(l[i])*dp;
+  }
+  p1 = factorial(deg(sp)+1);
+printf("%8.5f sv %8.5f  sb %8.5f  %8.5f\n",des->h,sv,sb,sv+sb*sb*pen(sp)*pen(sp)/(p1*p1));
+  return(sv+sb*sb*pen(sp)*pen(sp)/(p1*p1));
+}
+
+static double mcp, clo, cup;
+
+/*
+  Initial bandwidth will be (by default)
+  k-nearest neighbors for k small, just large enough to
+  get defined estimate (unless user provided nonzero nn or fix-h components)
+*/
+
+int ainitband(lfd,sp,dv,des)
+lfdata *lfd;
+smpar *sp;
+deriv *dv;
+design *des;
+{ int lf_status, p, z, cri, noit, redo;
+  double ho, t[6];
+
+  if (lf_debug >= 2) mut_printf("ainitband:\n");
+  p = des->p;
+  cri = acri(sp);
+  noit = (cri!=AOK);
+  z = (int)(lfd->n*nn(sp));
+  if ((noit) && (z<p+2)) z = p+2;
+  redo = 0; ho = -1;
+  do
+  { 
+    nbhd(lfd,des,z,redo,sp);
+    if (z<des->n) z = des->n;
+    if (des->h>ho) lf_status = locfit(lfd,des,sp,noit,0,0);
+    z++;
+    redo = 1;
+  } while ((z<=lfd->n) && ((des->h==0)||(lf_status!=LF_OK)));
+  hmin = des->h;
+
+  switch(cri)
+  { case ACP:
+      local_df(lfd,sp,des,t);
+      mcp = adcri(des->llk,t[0],t[2],pen(sp));
+      return(lf_status);
+    case AKAT:
+      local_df(lfd,sp,des,t);
+      clo = des->cf[0]-pen(sp)*t[5];
+      cup = des->cf[0]+pen(sp)*t[5];
+      return(lf_status);
+    case AMDI:
+      mcp = mmse(lfd,sp,dv,des);
+      return(lf_status);
+    case AOK: return(lf_status);
+  }
+  LERR(("aband1: unknown criterion"));
+  return(LF_ERR);
+}
+
+/*
+  aband2 increases the initial bandwidth until lack of fit results,
+  or the fit is close to a global fit. Increase h by 1+0.3/d at
+  each iteration.
+*/
+
+double aband2(lfd,sp,dv,des,h0)
+lfdata *lfd;
+smpar *sp;
+deriv *dv;
+design *des;
+double h0;
+{ double t[6], h1, nu1, cp, ncp, tlo, tup;
+  int d, inc, n, p, done;
+
+  if (lf_debug >= 2) mut_printf("aband2:\n");
+  d = lfd->d; n = lfd->n; p = npar(sp);
+  h1 = des->h = h0;
+  done = 0; nu1 = 0.0;
+  inc = 0; ncp = 0.0;
+  while ((!done) & (nu1<(n-p)*0.95))
+  { fixh(sp) = (1+0.3/d)*des->h;
+    nbhd(lfd,des,0,1,sp);
+    if (locfit(lfd,des,sp,1,0,0) > 0) WARN(("aband2: failed fit"));
+    local_df(lfd,sp,des,t);
+    nu1 = t[0]-t[2]; /* tr(A) */
+    switch(acri(sp))
+    { case AKAT:
+        tlo = des->cf[0]-pen(sp)*t[5];
+        tup = des->cf[0]+pen(sp)*t[5];
+/* mut_printf("h %8.5f  tlo %8.5f  tup %8.5f\n",des->h,tlo,tup); */
+        done = ((tlo>cup) | (tup<clo));
+        if (!done)
+        { clo = MAX(clo,tlo);
+          cup = MIN(cup,tup);
+          h1 = des->h;
+        }
+        break;
+      case ACP:
+        cp = adcri(des->llk,t[0],t[2],pen(sp));
+/* mut_printf("h %8.5f  lk %8.5f  t0 %8.5f  t2 %8.5f  cp %8.5f\n",des->h,des->llk,t[0],t[2],cp); */
+        if (cp<mcp) { mcp = cp; h1 = des->h; }
+        if (cp>=ncp) inc++; else inc = 0;
+        ncp = cp;
+        done = (inc>=10) | ((inc>=3) & ((t[0]-t[2])>=10) & (cp>1.5*mcp));
+        break;
+      case AMDI:
+        cp = mmse(lfd,sp,dv,des);
+        if (cp<mcp) { mcp = cp; h1 = des->h; }
+        if (cp>ncp) inc++; else inc = 0;
+        ncp = cp;
+        done = (inc>=3);
+        break;
+    }
+  }
+  return(h1);
+}
+
+/*
+  aband3 does a finer search around best h so far. Try
+  h*(1-0.2/d), h/(1-0.1/d), h*(1+0.1/d), h*(1+0.2/d)
+*/
+double aband3(lfd,sp,dv,des,h0)
+lfdata *lfd;
+smpar *sp;
+deriv *dv;
+design *des;
+double h0;
+{ double t[6], h1, cp, tlo, tup;
+  int i, i0, d, n;
+
+  if (lf_debug >= 2) mut_printf("aband3:\n");
+  d = lfd->d; n = lfd->n;
+  h1 = h0;
+  i0 = (acri(sp)==AKAT) ? 1 : -2;
+  if (h0==hmin) i0 = 1;
+
+  for (i=i0; i<=2; i++)
+  { if (i==0) i++;
+    fixh(sp) = h0*(1+0.1*i/d);
+    nbhd(lfd,des,0,1,sp);
+    if (locfit(lfd,des,sp,1,0,0) > 0) WARN(("aband3: failed fit"));
+    local_df(lfd,sp,des,t);
+    switch (acri(sp))
+    { case AKAT:
+        tlo = des->cf[0]-pen(sp)*t[5];
+        tup = des->cf[0]+pen(sp)*t[5];
+        if ((tlo>cup) | (tup<clo)) /* done */
+          i = 2;
+        else
+        { h1 = des->h;
+          clo = MAX(clo,tlo);
+          cup = MIN(cup,tup);
+        }
+        break;
+      case ACP:
+        cp = adcri(des->llk,t[0],t[2],pen(sp));
+        if (cp<mcp) { mcp = cp; h1 = des->h; }
+        else
+        { if (i>0) i = 2; }
+        break;
+      case AMDI:
+        cp = mmse(lfd,sp,dv,des);
+        if (cp<mcp) { mcp = cp; h1 = des->h; }
+        else
+        { if (i>0) i = 2; }
+    }
+  }
+  return(h1);
+}
+
+int alocfit(lfd,sp,dv,des,cv)
+lfdata *lfd;
+smpar *sp;
+deriv *dv;
+design *des;
+int cv;
+{ int lf_status;
+  double h0;
+
+  lf_status = ainitband(lfd,sp,dv,des);
+  if (lf_error) return(lf_status);
+  if (acri(sp) == AOK) return(lf_status);
+
+  h0 = fixh(sp);
+  fixh(sp) = aband2(lfd,sp,dv,des,des->h);
+  fixh(sp) = aband3(lfd,sp,dv,des,fixh(sp));
+  nbhd(lfd,des,0,1,sp);
+  lf_status = locfit(lfd,des,sp,0,0,cv);
+  fixh(sp) = h0;
+
+  return(lf_status);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *
+ *   Evaluate the locfit fitting functions.
+ *     calcp(sp,d)
+ *       calculates the number of fitting functions.
+ *     makecfn(sp,des,dv,d)
+ *       makes the coef.number vector.
+ *     fitfun(lfd, sp, x,t,f,dv)
+ *       lfd is the local fit structure.
+ *       sp  smoothing parameter structure.
+ *       x is the data point.
+ *       t is the fitting point.
+ *       f is a vector to return the results.
+ *       dv derivative structure.
+ *     designmatrix(lfd, sp, des)
+ *       is a wrapper for fitfun to build the design matrix.
+ *
+ */
+
+#include "locf.h"
+
+int calcp(sp,d)
+smpar *sp;
+int d;
+{ int i, k;
+
+  if (ubas(sp)) return(npar(sp));
+
+  switch (kt(sp))
+  { case KSPH:
+    case KCE:
+      k = 1;
+      for (i=1; i<=deg(sp); i++) k = k*(d+i)/i;
+      return(k);
+    case KPROD: return(d*deg(sp)+1);
+    case KLM: return(d);
+    case KZEON: return(1);
+  }
+  LERR(("calcp: invalid kt %d",kt(sp)));
+  return(0);
+}
+
+int coefnumber(dv,kt,d,deg)
+int kt, d, deg;
+deriv *dv;
+{ int d0, d1, t;
+
+  if (d==1)
+  { if (dv->nd<=deg) return(dv->nd);
+    return(-1);
+  }
+
+  if (dv->nd==0) return(0);
+  if (deg==0) return(-1);
+  if (dv->nd==1) return(1+dv->deriv[0]);
+  if (deg==1) return(-1);
+  if (kt==KPROD) return(-1);
+
+  if (dv->nd==2)
+  { d0 = dv->deriv[0]; d1 = dv->deriv[1];
+    if (d0<d1) { t = d0; d0 = d1; d1 = t; }
+    return((d+1)*(d0+1)-d0*(d0+3)/2+d1);
+  }
+  if (deg==2) return(-1);
+
+  LERR(("coefnumber not programmed for nd>=3"));
+  return(-1);
+}
+
+void makecfn(sp,des,dv,d)
+smpar *sp;
+design *des;
+deriv *dv;
+int d;
+{ int i, nd;
+  
+  nd = dv->nd;
+
+  des->cfn[0] = coefnumber(dv,kt(sp),d,deg(sp));
+  des->ncoef = 1;
+  if (nd >= deg(sp)) return;
+  if (kt(sp)==KZEON) return;
+
+  if (d>1)
+  { if (nd>=2) return;
+    if ((nd>=1) && (kt(sp)==KPROD)) return;
+  }
+
+  dv->nd = nd+1;
+  for (i=0; i<d; i++)
+  { dv->deriv[nd] = i;
+    des->cfn[i+1] = coefnumber(dv,kt(sp),d,deg(sp));
+  }
+  dv->nd = nd;
+
+  des->ncoef = 1+d;
+}
+
+void fitfunangl(dx,ff,sca,cd,deg)
+double dx, *ff, sca;
+int deg, cd;
+{
+  if (deg>=3) WARN(("Can't handle angular model with deg>=3"));
+
+  switch(cd)
+  { case 0:
+      ff[0] = 1;
+      ff[1] = sin(dx/sca)*sca;
+      ff[2] = (1-cos(dx/sca))*sca*sca;
+      return;
+    case 1:
+      ff[0] = 0;
+      ff[1] = cos(dx/sca);
+      ff[2] = sin(dx/sca)*sca;
+      return;
+    case 2:
+      ff[0] = 0;
+      ff[1] = -sin(dx/sca)/sca;
+      ff[2] = cos(dx/sca);
+      return;
+    default: WARN(("Can't handle angular model with >2 derivs"));
+  }
+}
+
+void fitfun(lfd,sp,x,t,f,dv)
+lfdata *lfd;
+smpar *sp;
+double *x, *t, *f;
+deriv *dv;
+{ int d, deg, nd, m, i, j, k, ct_deriv[MXDIM];
+  double ff[MXDIM][1+MXDEG], dx[MXDIM], *xx[MXDIM];
+
+  if (ubas(sp))
+  { for (i=0; i<lfd->d; i++) xx[i] = &x[i];
+    i = 0;
+    sp->vbasis(xx,t,1,lfd->d,1,npar(sp),f);
+    return;
+  }
+
+  d = lfd->d;
+  deg = deg(sp);
+  m = 0;
+  nd = (dv==NULL) ? 0 : dv->nd;
+
+  if (kt(sp)==KZEON)
+  { f[0] = 1.0;
+    return;
+  }
+
+  if (kt(sp)==KLM)
+  { for (i=0; i<d; i++) f[m++] = x[i];
+    return;
+  }
+
+  f[m++] = (nd==0);
+  if (deg==0) return;
+
+  for (i=0; i<d; i++)
+  { ct_deriv[i] = 0;
+    dx[i] = (t==NULL) ? x[i] : x[i]-t[i];
+  }
+  for (i=0; i<nd; i++) ct_deriv[dv->deriv[i]]++;
+
+  for (i=0; i<d; i++)
+  { switch(lfd->sty[i])
+    {
+      case STANGL:
+        fitfunangl(dx[i],ff[i],lfd->sca[i],ct_deriv[i],deg(sp));
+        break;
+      default:
+        for (j=0; j<ct_deriv[i]; j++) ff[i][j] = 0.0;
+        ff[i][ct_deriv[i]] = 1.0;
+        for (j=ct_deriv[i]+1; j<=deg; j++)
+          ff[i][j] = ff[i][j-1]*dx[i]/(j-ct_deriv[i]);
+    }
+  }
+
+/*
+ *  Product kernels. Note that if ct_deriv[i] != nd, that implies
+ *  there is differentiation wrt another variable, and all components
+ *  involving x[i] are 0.
+ */
+  if ((d==1) || (kt(sp)==KPROD))
+  { for (j=1; j<=deg; j++)
+      for (i=0; i<d; i++)
+        f[m++] = (ct_deriv[i]==nd) ? ff[i][j] : 0.0;
+    return;
+  }
+
+/*
+ *  Spherical kernels with the full polynomial basis.
+ *  Presently implemented up to deg=3.
+ */
+  for (i=0; i<d; i++)
+    f[m++] = (ct_deriv[i]==nd) ? ff[i][1] : 0.0;
+  if (deg==1) return;
+
+  for (i=0; i<d; i++)
+  {
+    /* xi^2/2 terms. */
+    f[m++] = (ct_deriv[i]==nd) ? ff[i][2] : 0.0;
+
+    /* xi xj terms */
+    for (j=i+1; j<d; j++)
+      f[m++] = (ct_deriv[i]+ct_deriv[j]==nd) ? ff[i][1]*ff[j][1] : 0.0;
+  }
+  if (deg==2) return;
+
+  for (i=0; i<d; i++)
+  { 
+    /* xi^3/6 terms */
+    f[m++] = (ct_deriv[i]==nd) ? ff[i][3] : 0.0;
+
+    /* xi^2/2 xk terms */
+    for (k=i+1; k<d; k++)
+      f[m++] = (ct_deriv[i]+ct_deriv[k]==nd) ? ff[i][2]*ff[k][1] : 0.0;
+
+    /* xi xj xk terms */
+    for (j=i+1; j<d; j++)
+    { f[m++] = (ct_deriv[i]+ct_deriv[j]==nd) ? ff[i][1]*ff[j][2] : 0.0;
+      for (k=j+1; k<d; k++)
+        f[m++] = (ct_deriv[i]+ct_deriv[j]+ct_deriv[k]==nd) ?
+                    ff[i][1]*ff[j][1]*ff[k][1] : 0.0;
+    }
+  }
+  if (deg==3) return;
+
+  LERR(("fitfun: can't handle deg=%d for spherical kernels",deg));
+}
+
+/*
+ *  Build the design matrix. Assumes des->ind contains the indices of
+ *  the required data points; des->n the number of points; des->xev
+ *  the fitting point.
+ */
+void designmatrix(lfd,sp,des)
+lfdata *lfd;
+smpar *sp;
+design *des;
+{ int i, ii, j, p;
+  double *X, u[MXDIM];
+
+  X = d_x(des);
+  p = des->p;
+
+  if (ubas(sp))
+  {
+    sp->vbasis(lfd->x,des->xev,lfd->n,lfd->d,des->n,p,X);
+    return;
+  }
+
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    for (j=0; j<lfd->d; j++) u[j] = datum(lfd,j,ii);
+    fitfun(lfd,sp,u,des->xev,&X[ii*p],NULL);
+  }
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *
+ *
+ *  Functions for determining bandwidth; smoothing neighborhood
+ *  and smoothing weights.
+ */
+
+#include "locf.h"
+
+double rho(x,sc,d,kt,sty) /* ||x|| for appropriate distance metric */
+double *x, *sc;
+int d, kt, *sty;
+{ double rhoi[MXDIM], s;
+  int i;
+  for (i=0; i<d; i++)
+  { if (sty!=NULL)
+    { switch(sty[i])
+      { case STANGL:  rhoi[i] = 2*sin(x[i]/(2*sc[i])); break;
+        case STCPAR: rhoi[i] = 0; break;
+        default: rhoi[i] = x[i]/sc[i];
+    } }
+    else rhoi[i] = x[i]/sc[i];
+  }
+
+  if (d==1) return(fabs(rhoi[0]));
+
+  s = 0;
+  if (kt==KPROD)
+  { for (i=0; i<d; i++)
+    { rhoi[i] = fabs(rhoi[i]);
+      if (rhoi[i]>s) s = rhoi[i];
+    }
+    return(s);
+  }
+
+  if (kt==KSPH)
+  { for (i=0; i<d; i++)
+      s += rhoi[i]*rhoi[i];
+    return(sqrt(s));
+  }
+
+  LERR(("rho: invalid kt"));
+  return(0.0);
+}
+
+double kordstat(x,k,n,ind)
+double *x;
+int k, n, *ind;
+{ int i, i0, i1, l, r;
+  double piv;
+  if (k<1) return(0.0);
+  i0 = 0; i1 = n-1;
+  while (1)
+  { piv = x[ind[(i0+i1)/2]];
+    l = i0; r = i1;
+    while (l<=r)
+    { while ((l<=i1) && (x[ind[l]]<=piv)) l++;
+      while ((r>=i0) && (x[ind[r]]>piv)) r--;
+      if (l<=r) ISWAP(ind[l],ind[r]);
+    } /* now, x[ind[i0..r]] <= piv < x[ind[l..i1]] */
+    if (r<k-1) i0 = l;  /* go right */
+    else /* put pivots in middle */
+    { for (i=i0; i<=r; )
+        if (x[ind[i]]==piv) { ISWAP(ind[i],ind[r]); r--; }
+        else i++;
+      if (r<k-1) return(piv);
+      i1 = r;
+    }
+  }
+}
+
+/* check if i'th data point is in limits */
+int inlim(lfd,i)
+lfdata *lfd;
+int i;
+{ int d, j, k;
+  double *xlim;
+
+  xlim = lfd->xl;
+  d = lfd->d;
+  k = 1;
+  for (j=0; j<d; j++)
+  { if (xlim[j]<xlim[j+d])
+      k &= ((datum(lfd,j,i)>=xlim[j]) & (datum(lfd,j,i)<=xlim[j+d]));
+  }
+  return(k);
+}
+
+double compbandwid(di,ind,x,n,d,nn,fxh)
+double *di, *x, fxh;
+int n, d, nn, *ind;
+{ int i;
+  double nnh;
+
+  if (nn==0) return(fxh);
+
+  if (nn<n)
+    nnh = kordstat(di,nn,n,ind);
+  else
+  { nnh = 0;
+    for (i=0; i<n; i++) nnh = MAX(nnh,di[i]);
+    nnh = nnh*exp(log(1.0*nn/n)/d);
+  }
+  return(MAX(fxh,nnh));
+}
+
+/*
+  fast version of nbhd for ordered 1-d data
+*/
+void nbhd1(lfd,sp,des,k)
+lfdata *lfd;
+smpar *sp;
+design *des;
+int k;
+{ double x, h, *xd, sc;
+  int i, l, r, m, n, z;
+
+  n = lfd->n;
+  x = des->xev[0];
+  xd = dvari(lfd,0);
+  sc = lfd->sca[0];
+
+  /* find closest data point to x */
+  if (x<=xd[0]) z = 0;
+  else
+  if (x>=xd[n-1]) z = n-1;
+  else
+  { l = 0; r = n-1;
+    while (r-l>1)
+    { z = (r+l)/2;
+      if (xd[z]>x) r = z;
+              else l = z;
+    }
+    /* now, xd[0..l] <= x < x[r..n-1] */
+    if ((x-xd[l])>(xd[r]-x)) z = r; else z = l;
+  }
+  /* closest point to x is xd[z] */
+
+  if (nn(sp)<0)  /* user bandwidth */
+    h = sp->vb(des->xev);
+  else
+  { if (k>0) /* set h to nearest neighbor bandwidth */
+    { l = r = z;
+      if (l==0) r = k-1;
+      if (r==n-1) l = n-k;
+      while (r-l<k-1)
+      { if ((x-xd[l-1])<(xd[r+1]-x)) l--; else r++;
+        if (l==0) r = k-1;
+        if (r==n-1) l = n-k;
+      }
+      h = x-xd[l];
+      if (h<xd[r]-x) h = xd[r]-x;
+    }
+    else h = 0;
+    h /= sc;
+    if (h<fixh(sp)) h = fixh(sp);
+  }
+
+  m = 0;
+  if (xd[z]>x) z--; /* so xd[z]<=x */
+  /* look left */
+  for (i=z; i>=0; i--) if (inlim(lfd,i))
+  { dist(des,i) = (x-xd[i])/sc;
+    wght(des,i) = weight(lfd, sp, &xd[i], &x, h, 1, dist(des,i));
+    if (wght(des,i)>0)
+    { des->ind[m] = i;
+      m++; 
+    } else i = 0;
+  }
+  /* look right */
+  for (i=z+1; i<n; i++) if (inlim(lfd,i))
+  { dist(des,i) = (xd[i]-x)/sc;
+    wght(des,i) = weight(lfd, sp, &xd[i], &x, h, 1, dist(des,i));
+    if (wght(des,i)>0)
+    { des->ind[m] = i;
+      m++; 
+    } else i = n;
+  }
+
+  des->n = m;
+  des->h = h;
+}
+
+void nbhd_zeon(lfd,des)
+lfdata *lfd;
+design *des;
+{ int i, j, m, eq;
+
+  m = 0;
+  for (i=0; i<lfd->n; i++)
+  { eq = 1;
+    for (j=0; j<lfd->d; j++) eq = eq && (des->xev[j] == datum(lfd,j,i));
+    if (eq)
+    { wght(des,i) = 1;
+      des->ind[m] = i;
+      m++;
+    }
+  }
+  des->n = m;
+  des->h = 1.0;
+}
+
+void nbhd(lfd,des,nn,redo,sp)
+lfdata *lfd;
+design *des;
+int redo, nn;
+smpar *sp;
+{ int d, i, j, m, n;
+  double h, u[MXDIM];
+
+  if (lf_debug>1) mut_printf("nbhd: nn %d  fixh %8.5f\n",nn,fixh(sp));
+  
+  d = lfd->d; n = lfd->n;
+
+  if (ker(sp)==WPARM)
+  { for (i=0; i<n; i++)
+    { wght(des,i) = 1.0;
+      des->ind[i] = i;
+    }
+    des->n = n;
+    return;
+  }
+
+  if (kt(sp)==KZEON)
+  { nbhd_zeon(lfd,des);
+    return;
+  }
+
+  if (kt(sp)==KCE)
+  { des->h = 0.0;
+    return;
+  }
+
+  /* ordered 1-dim; use fast searches */
+  if ((nn<=n) & (lfd->ord) & (ker(sp)!=WMINM) & (lfd->sty[0]!=STANGL))
+  { nbhd1(lfd,sp,des,nn);
+    return;
+  }
+
+  if (!redo)
+  { for (i=0; i<n; i++)
+    { for (j=0; j<d; j++) u[j] = datum(lfd,j,i)-des->xev[j];
+      dist(des,i) = rho(u,lfd->sca,d,kt(sp),lfd->sty);
+      des->ind[i] = i;
+    }
+  }
+  else
+    for (i=0; i<n; i++) des->ind[i] = i;
+
+  if (ker(sp)==WMINM)
+  { des->h = minmax(lfd,des,sp);
+    return;
+  }
+
+  if (nn<0)
+    h = sp->vb(des->xev);
+  else
+    h = compbandwid(des->di,des->ind,des->xev,n,lfd->d,nn,fixh(sp));
+  m = 0;
+  for (i=0; i<n; i++) if (inlim(lfd,i))
+  { for (j=0; j<d; j++) u[j] = datum(lfd,j,i);
+    wght(des,i) = weight(lfd, sp, u, des->xev, h, 1, dist(des,i));
+    if (wght(des,i)>0)
+    { des->ind[m] = i;
+      m++;
+    }
+  }
+  des->n = m;
+  des->h = h;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *
+ *   This file includes functions to solve for the scale estimate in
+ *   local robust regression and likelihood. The main entry point is
+ *   lf_robust(lfd,sp,des,mxit),
+ *   called from the locfit() function.
+ *
+ *   The update_rs(x) accepts a residual scale x as the argument (actually,
+ *   it works on the log-scale). The function computes the local fit
+ *   assuming this residual scale, and re-estimates the scale from this
+ *   new fit. The final solution satisfies the fixed point equation
+ *   update_rs(x)=x. The function lf_robust() automatically calls
+ *   update_rs() through the fixed point iterations.
+ *
+ *   The estimation of the scale from the fit is based on the sqrt of
+ *   the median deviance of observations with non-zero weights (in the
+ *   gaussian case, this is the median absolute residual).
+ *
+ *   TODO:
+ *     Should use smoothing weights in the median.
+ */
+
+#include "locf.h"
+
+extern int lf_status;
+double robscale;
+
+static lfdata *rob_lfd;
+static smpar *rob_sp;
+static design *rob_des;
+static int rob_mxit;
+
+double median(x,n)
+double *x;
+int n;
+{ int i, j, lt, eq, gt;
+  double lo, hi, s;
+  lo = hi = x[0];
+  for (i=0; i<n; i++)
+  { lo = MIN(lo,x[i]);
+    hi = MAX(hi,x[i]);
+  }
+  if (lo==hi) return(lo);
+  lo -= (hi-lo);
+  hi += (hi-lo);
+  for (i=0; i<n; i++)
+  { if ((x[i]>lo) & (x[i]<hi))
+    { s = x[i]; lt = eq = gt = 0;
+      for (j=0; j<n; j++)
+      { lt += (x[j]<s);
+        eq += (x[j]==s);
+        gt += (x[j]>s);
+      }
+      if ((2*(lt+eq)>n) && (2*(gt+eq)>n)) return(s);
+      if (2*(lt+eq)<=n) lo = s;
+      if (2*(gt+eq)<=n) hi = s;
+    }
+  }
+  return((hi+lo)/2);
+}
+
+double nrobustscale(lfd,sp,des,rs)
+lfdata *lfd;
+smpar *sp;
+design *des;
+double rs;
+{ int i, ii, p;
+  double link[LLEN], sc, sd, sw, e;
+  p = des->p; sc = sd = sw = 0.0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    fitv(des,ii) = base(lfd,ii)+innerprod(des->cf,d_xi(des,ii),p);
+    e = resp(lfd,ii)-fitv(des,ii);
+    stdlinks(link,lfd,sp,ii,fitv(des,ii),rs);
+    sc += wght(des,ii)*e*link[ZDLL];
+    sd += wght(des,ii)*e*e*link[ZDDLL];
+    sw += wght(des,ii);
+  }
+
+  /* newton-raphson iteration for log(s)
+     -psi(ei/s) - log(s); s = e^{-th}
+  */
+  rs *= exp((sc-sw)/(sd+sc));
+  return(rs);
+}
+
+double robustscale(lfd,sp,des)
+lfdata *lfd;
+smpar *sp;
+design *des;
+{ int i, ii, p, fam, lin, or;
+  double rs, link[LLEN];
+  p = des->p;
+  fam = fam(sp);
+  lin = link(sp);
+  or = fami(sp)->robust;
+  fami(sp)->robust = 0;
+
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    fitv(des,ii) = base(lfd,ii) + innerprod(des->cf,d_xi(des,ii),p);
+    links(fitv(des,ii),resp(lfd,ii),fami(sp),lin,link,cens(lfd,ii),prwt(lfd,ii),1.0);
+    des->res[i] = -2*link[ZLIK];
+  }
+  fami(sp)->robust = or;
+  rs = sqrt(median(des->res,des->n));
+
+  if (rs==0.0) rs = 1.0;
+  return(rs);
+}
+
+double update_rs(x)
+double x;
+{ double nx;
+  if (lf_status != LF_OK) return(x);
+  robscale = exp(x);
+  lfiter(rob_lfd,rob_sp,rob_des,rob_mxit);
+  if (lf_status != LF_OK) return(x);
+
+  nx = log(robustscale(rob_lfd,rob_sp,rob_des));
+  if (nx<x-0.2) nx = x-0.2;
+  return(nx);
+}
+
+void lf_robust(lfd,sp,des,mxit)
+lfdata *lfd;
+design *des;
+smpar *sp;
+int mxit;
+{ double x;
+  rob_lfd = lfd;
+  rob_des = des;
+  rob_sp = sp;
+  rob_mxit = mxit;
+  lf_status = LF_OK;
+
+  x = log(robustscale(lfd,sp,des));
+
+  solve_fp(update_rs, x, 1.0e-6, mxit);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *   Post-fitting functions to compute the local variance and
+ *   influence functions. Also the local degrees of freedom
+ *   calculations for adaptive smoothing.
+ */
+
+#include "locf.h"
+
+extern double robscale;
+
+/*
+  vmat() computes (after the local fit..) the matrix 
+  M2  = X^T W^2 V X.
+  M12 = (X^T W V X)^{-1} M2
+  Also, for convenience, tr[0] = sum(wi) tr[1] = sum(wi^2).
+*/
+void vmat(lfd, sp, des, M12, M2)
+lfdata *lfd;
+smpar *sp;
+design *des;
+double *M12, *M2;
+{ int i, ii, p, nk, ok;
+  double link[LLEN], h, ww, tr0, tr1;
+  p = des->p;
+  setzero(M2,p*p);
+
+  nk = -1;
+
+  /* for density estimation, use integral rather than
+     sum form, if W^2 is programmed...
+  */
+  if ((fam(sp)<=THAZ) && (link(sp)==LLOG))
+  { switch(ker(sp))
+    { case WGAUS: nk = WGAUS; h = des->h/SQRT2; break;
+      case WRECT: nk = WRECT; h = des->h; break;
+      case WEPAN: nk = WBISQ; h = des->h; break;
+      case WBISQ: nk = WQUQU; h = des->h; break;
+      case WTCUB: nk = W6CUB; h = des->h; break;
+      case WEXPL: nk = WEXPL; h = des->h/2; break;
+    }
+  }
+
+  tr0 = tr1 = 0.0;
+  if (nk != -1)
+  { ok = ker(sp); ker(sp) = nk;
+/* compute M2 using integration. Use M12 as work matrix. */
+    (des->itype)(des->xev, M2, M12, des->cf, h);
+    ker(sp) = ok;
+    if (fam(sp)==TDEN) multmatscal(M2,des->smwt,p*p);
+    tr0 = des->ss[0];
+    tr1 = M2[0]; /* n int W e^<a,A> */
+  }
+  else
+  { for (i=0; i<des->n; i++)
+    { ii = des->ind[i];
+      stdlinks(link,lfd,sp,ii,fitv(des,ii),robscale);
+      ww = SQR(wght(des,ii))*link[ZDDLL];
+      tr0 += wght(des,ii);
+      tr1 += SQR(wght(des,ii));
+      addouter(M2,d_xi(des,ii),d_xi(des,ii),p,ww);
+    }
+  }
+  des->tr0 = tr0;
+  des->tr1 = tr1;
+
+  memcpy(M12,M2,p*p*sizeof(double));
+  for (i=0; i<p; i++)
+    jacob_solve(&des->xtwx,&M12[i*p]);
+}
+
+void lf_vcov(lfd,sp,des)
+lfdata *lfd;
+smpar *sp;
+design *des;
+{ int i, j, k, p;
+  double *M12, *M2;
+  M12 = des->V; M2 = des->P; p = des->p;
+  vmat(lfd,sp,des,M12,M2); /* M2 = X^T W^2 V X  tr0=sum(W) tr1=sum(W*W) */
+  des->tr2 = m_trace(M12,p);   /* tr (XTWVX)^{-1}(XTW^2VX) */
+
+/*
+ * Covariance matrix is M1^{-1} * M2 * M1^{-1}
+ * We compute this using the cholesky decomposition of
+ * M2; premultiplying by M1^{-1} and squaring. This
+ * is more stable than direct computation in near-singular cases.
+ */
+  chol_dec(M2,p,p);
+  for (i=0; i<p; i++)
+    for (j=0; j<i; j++)
+    { M2[j*p+i] = M2[i*p+j];
+      M2[i*p+j] = 0.0;
+    }
+  for (i=0; i<p; i++) jacob_solve(&des->xtwx,&M2[i*p]);
+  for (i=0; i<p; i++)
+  { for (j=0; j<p; j++)
+    { M12[i*p+j] = 0;
+      for (k=0; k<p; k++)
+        M12[i*p+j] += M2[k*p+i]*M2[k*p+j]; /* ith column of covariance */
+    }
+  }
+  if ((fam(sp)==TDEN) && (link(sp)==LIDENT))
+    multmatscal(M12,1/SQR(des->smwt),p*p);
+
+/* this computes the influence function as des->f1[0]. */
+  unitvec(des->f1,0,des->p);
+  jacob_solve(&des->xtwx,des->f1);
+}
+
+/* local_df computes:
+ *   tr[0] = trace(W)
+ *   tr[1] = trace(W*W)
+ *   tr[2] = trace( M1^{-1} M2 )
+ *   tr[3] = trace( M1^{-1} M3 )
+ *   tr[4] = trace( (M1^{-1} M2)^2 )
+ *   tr[5] = var(theta-hat).
+ */
+void local_df(lfd,sp,des,tr)
+lfdata *lfd;
+smpar *sp;
+design *des;
+double *tr;
+{ int i, ii, j, p;
+  double *m2, *V, ww, link[LLEN];
+
+  tr[0] = tr[1] = tr[2] = tr[3] = tr[4] = tr[5] = 0.0;
+  m2 = des->V; V = des->P; p = des->p;
+
+  vmat(lfd,sp,des,m2,V);  /* M = X^T W^2 V X  tr0=sum(W) tr1=sum(W*W) */
+  tr[0] = des->tr0;
+  tr[1] = des->tr1;
+  tr[2] = m_trace(m2,p);   /* tr (XTWVX)^{-1}(XTW^2VX) */
+
+  unitvec(des->f1,0,p);
+  jacob_solve(&des->xtwx,des->f1);
+  for (i=0; i<p; i++)
+    for (j=0; j<p; j++)
+    { tr[4] += m2[i*p+j]*m2[j*p+i];  /* tr(M^2) */
+      tr[5] += des->f1[i]*V[i*p+j]*des->f1[j]; /* var(thetahat) */
+  }
+  tr[5] = sqrt(tr[5]);
+
+  setzero(m2,p*p);
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    stdlinks(link,lfd,sp,ii,fitv(des,ii),robscale);
+    ww = wght(des,ii)*wght(des,ii)*wght(des,ii)*link[ZDDLL];
+    addouter(m2,d_xi(des,ii),d_xi(des,ii),p,ww);
+  }
+  for (i=0; i<p; i++)
+  { jacob_solve(&des->xtwx,&m2[i*p]);
+    tr[3] += m2[i*(p+1)];
+  }
+
+  return;
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *  Routines for computing weight diagrams.
+ *     wdiag(lf,des,lx,deg,ty,exp)
+ *  Must locfit() first, unless ker==WPARM and has par. comp.
+ *  
+ */
+
+#include "locf.h"
+
+static double *wd;
+extern double robscale;
+void nnresproj(lfd,sp,des,u,m,p)
+lfdata *lfd;
+smpar *sp;
+design *des;
+double *u;
+int m, p;
+{ int i, ii, j;
+  double link[LLEN];
+  setzero(des->f1,p);
+  for (j=0; j<m; j++)
+  { ii = des->ind[j];
+    stdlinks(link,lfd,sp,ii,fitv(des,ii),robscale);
+    for (i=0; i<p; i++) des->f1[i] += link[ZDDLL]*d_xij(des,j,ii)*u[j];
+  }
+  jacob_solve(&des->xtwx,des->f1);
+  for (i=0; i<m; i++)
+  { ii = des->ind[i];
+    u[i] -= innerprod(des->f1,d_xi(des,ii),p)*wght(des,ii);
+  }
+}
+
+void wdexpand(l,n,ind,m)
+double *l;
+int *ind, n, m;
+{ int i, j, t;
+  double z;
+  for (j=m; j<n; j++) { l[j] = 0.0; ind[j] = -1; }
+  j = m-1;
+  while (j>=0)
+  { if (ind[j]==j) j--;
+    else
+    { i = ind[j];
+      z = l[j]; l[j] = l[i]; l[i] = z;
+      t = ind[j]; ind[j] = ind[i]; ind[i] = t;
+      if (ind[j]==-1) j--;
+    }
+  }
+
+/*  for (i=n-1; i>=0; i--)
+  { l[i] = ((j>=0) && (ind[j]==i)) ? l[j--] : 0.0; } */
+}
+
+int wdiagp(lfd,sp,des,lx,pc,dv,deg,ty,exp)
+lfdata *lfd;
+smpar *sp;
+design *des;
+paramcomp *pc;
+deriv *dv;
+double *lx;
+int deg, ty, exp;
+{ int i, j, p, nd;
+  double *l1;
+
+  p = des->p;
+
+  fitfun(lfd,sp,des->xev,pc->xbar,des->f1,dv);
+  if (exp)
+  { jacob_solve(&pc->xtwx,des->f1);
+    for (i=0; i<lfd->n; i++)
+      lx[i] = innerprod(des->f1,d_xi(des,des->ind[i]),p);
+    return(lfd->n);
+  }
+  jacob_hsolve(&pc->xtwx,des->f1);
+  for (i=0; i<p; i++) lx[i] = des->f1[i];
+
+  nd = dv->nd;
+  dv->nd = nd+1;
+  if (deg>=1)
+    for (i=0; i<lfd->d; i++)
+    { dv->deriv[nd] = i;
+      l1 = &lx[(i+1)*p];
+      fitfun(lfd,sp,des->xev,pc->xbar,l1,dv);
+      jacob_hsolve(&pc->xtwx,l1);
+    }
+
+  dv->nd = nd+2;
+  if (deg>=2)
+    for (i=0; i<lfd->d; i++)
+    { dv->deriv[nd] = i;
+      for (j=0; j<lfd->d; j++)
+      { dv->deriv[nd+1] = j;
+        l1 = &lx[(i*lfd->d+j+lfd->d+1)*p];
+        fitfun(lfd,sp,des->xev,pc->xbar,l1,dv);
+        jacob_hsolve(&pc->xtwx,l1);
+    } }
+  dv->nd = nd;
+  return(p);
+}
+
+int wdiag(lfd,sp,des,lx,dv,deg,ty,exp)
+lfdata *lfd;
+smpar *sp;
+design *des;
+deriv *dv;
+double *lx;
+int deg, ty, exp;
+/* deg=0: l(x) only.
+   deg=1: l(x), l'(x)
+   deg=2: l(x), l'(x), l''(x)
+   ty = 1: e1 (X^T WVX)^{-1} X^T W        -- hat matrix
+   ty = 2: e1 (X^T WVX)^{-1} X^T WV^{1/2} -- scb's
+*/
+{ double w, *X, *lxd, *lxdd, wdd, wdw, *ulx, link[LLEN], h;
+  double dfx[MXDIM], hs[MXDIM];
+  int i, ii, j, k, l, m, d, p, nd;
+
+  h = des->h;
+  nd = dv->nd;
+  wd = des->wd;
+  d = lfd->d; p = des->p; X = d_x(des);
+  ulx = des->res;
+  m = des->n;
+  for (i=0; i<d; i++) hs[i] = h*lfd->sca[i];
+  if (deg>0)
+  { lxd = &lx[m];
+    setzero(lxd,m*d);
+    if (deg>1)
+    { lxdd = &lxd[d*m];
+      setzero(lxdd,m*d*d);
+  } }
+
+  if (nd>0) fitfun(lfd,sp,des->xev,des->xev,des->f1,dv); /* c(0) */
+    else unitvec(des->f1,0,p);
+  jacob_solve(&des->xtwx,des->f1);   /* c(0) (X^TWX)^{-1} */
+  for (i=0; i<m; i++)
+  { ii = des->ind[i];
+    lx[i] = innerprod(des->f1,&X[ii*p],p); /* c(0)(XTWX)^{-1}X^T */
+    if (deg>0)
+    { wd[i] = Wd(dist(des,ii)/h,ker(sp));
+      for (j=0; j<d; j++)
+      { dfx[j] = datum(lfd,j,ii)-des->xev[j];
+        lxd[j*m+i] = lx[i]*wght(des,ii)*weightd(dfx[j],lfd->sca[j],
+          d,ker(sp),kt(sp),h,lfd->sty[j],dist(des,ii));
+             /* c(0) (XTWX)^{-1}XTW' */
+      }
+      if (deg>1)
+      { wdd = Wdd(dist(des,ii)/h,ker(sp));
+        for (j=0; j<d; j++)
+          for (k=0; k<d; k++)
+          { w = (dist(des,ii)==0) ? 0 : h/dist(des,ii);
+            w = wdd * (des->xev[k]-datum(lfd,k,ii)) * (des->xev[j]-datum(lfd,j,ii))
+                  * w*w / (hs[k]*hs[k]*hs[j]*hs[j]);
+            if (j==k) w += wd[i]/(hs[j]*hs[j]);
+            lxdd[(j*d+k)*m+i] = lx[i]*w;
+              /* c(0)(XTWX)^{-1}XTW'' */
+          }
+      }
+    }
+    lx[i] *= wght(des,ii);
+  }
+
+  dv->nd = nd+1;
+  if (deg==2)
+  { for (i=0; i<d; i++)
+    { dv->deriv[nd] = i;
+      fitfun(lfd,sp,des->xev,des->xev,des->f1,dv);
+      for (k=0; k<m; k++)
+      { ii = des->ind[i];
+        stdlinks(link,lfd,sp,ii,fitv(des,ii),robscale);
+        for (j=0; j<p; j++)
+          des->f1[j] -= link[ZDDLL]*lxd[i*m+k]*X[ii*p+j];
+        /* c'(x)-c(x)(XTWX)^{-1}XTW'X */
+      }
+      jacob_solve(&des->xtwx,des->f1); /* (...)(XTWX)^{-1} */
+      for (j=0; j<m; j++)
+      { ii = des->ind[j];
+        ulx[j] = innerprod(des->f1,&X[ii*p],p); /* (...)XT */
+      }
+      for (j=0; j<d; j++)
+        for (k=0; k<m; k++)
+        { ii = des->ind[k];
+          dfx[j] = datum(lfd,j,ii)-des->xev[j];
+          wdw = wght(des,ii)*weightd(dfx[j],lfd->sca[j],d,ker(sp),
+            kt(sp),h,lfd->sty[j],dist(des,ii));
+          lxdd[(i*d+j)*m+k] += ulx[k]*wdw;
+          lxdd[(j*d+i)*m+k] += ulx[k]*wdw;
+        } /* + 2(c'-c(XTWX)^{-1}XTW'X)(XTWX)^{-1}XTW' */
+    }
+    for (j=0; j<d*d; j++) nnresproj(lfd,sp,des,&lxdd[j*m],m,p);
+        /* * (I-X(XTWX)^{-1} XTW */
+  }
+  if (deg>0)
+  { for (j=0; j<d; j++) nnresproj(lfd,sp,des,&lxd[j*m],m,p);
+      /* c(0)(XTWX)^{-1}XTW'(I-X(XTWX)^{-1}XTW) */
+    for (i=0; i<d; i++)
+    { dv->deriv[nd]=i;
+      fitfun(lfd,sp,des->xev,des->xev,des->f1,dv);
+      jacob_solve(&des->xtwx,des->f1);
+      for (k=0; k<m; k++)
+      { ii = des->ind[k];
+        for (l=0; l<p; l++)
+          lxd[i*m+k] += des->f1[l]*X[ii*p+l]*wght(des,ii);
+      } /* add c'(0)(XTWX)^{-1}XTW */
+    }
+  }
+
+  dv->nd = nd+2;
+  if (deg==2)
+  { for (i=0; i<d; i++)
+    { dv->deriv[nd]=i;
+      for (j=0; j<d; j++)
+      { dv->deriv[nd+1]=j;
+        fitfun(lfd,sp,des->xev,des->xev,des->f1,dv);
+        jacob_solve(&des->xtwx,des->f1);
+        for (k=0; k<m; k++)
+        { ii = des->ind[k];
+          for (l=0; l<p; l++)
+            lxdd[(i*d+j)*m+k] += des->f1[l]*X[ii*p+l]*wght(des,ii);
+        } /* + c''(x)(XTWX)^{-1}XTW */
+      }
+    }
+  }
+  dv->nd = nd;
+
+  k = 1+d*(deg>0)+d*d*(deg==2);
+
+  if (exp) wdexpand(lx,lfd->n,des->ind,m);
+ 
+  if (ty==1) return(m);
+  for (i=0; i<m; i++)
+  { ii = des->ind[i];
+    stdlinks(link,lfd,sp,ii,fitv(des,ii),robscale);
+    link[ZDDLL] = sqrt(fabs(link[ZDDLL]));
+    for (j=0; j<k; j++) lx[j*m+i] *= link[ZDDLL];
+  }
+  return(m);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *  String  matching functions. For a given argument string, find
+ *  the best match from an array of possibilities. Is there a library
+ *  function somewhere to do something like this?
+ *
+ *  return values of -1 indicate failure/unknown string.
+ */
+
+#include "locf.h"
+
+int ct_match(z1, z2)
+char *z1, *z2;
+{ int ct = 0;
+  while (z1[ct]==z2[ct])
+  { if (z1[ct]=='\0') return(ct+1);
+    ct++;
+  }
+  return(ct);
+}
+
+int pmatch(z, strings, vals, n, def)
+char *z, **strings;
+int *vals, n, def;
+{ int i, ct, best, best_ct;
+  best = -1;
+  best_ct = 0;
+
+  for (i=0; i<n; i++)
+  { ct = ct_match(z,strings[i]);
+    if (ct==strlen(z)+1) return(vals[i]);
+    if (ct>best_ct) { best = i; best_ct = ct; }
+  }
+  if (best==-1) return(def);
+  return(vals[best]);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+#include "locf.h"
+
+int lf_maxit = 20;
+int lf_debug = 0;
+int lf_error = 0;
+
+double s0, s1;
+static lfdata *lf_lfd;
+static design *lf_des;
+static smpar   *lf_sp;
+int lf_status;
+int ident=0;
+double lf_tol;
+extern double robscale;
+
+void lfdata_init(lfd)
+lfdata *lfd;
+{ int i;
+  for (i=0; i<MXDIM; i++)
+  { lfd->sty[i] = 0;
+    lfd->sca[i] = 1.0;
+    lfd->xl[i] = lfd->xl[i+MXDIM] = 0.0;
+  }
+  lfd->y = lfd->w = lfd->c = lfd->b = NULL;
+  lfd->d = lfd->n = 0;
+}
+
+void smpar_init(sp,lfd)
+smpar *sp;
+lfdata *lfd;
+{ nn(sp)  = 0.7;
+  fixh(sp)= 0.0;
+  pen(sp) = 0.0;
+  acri(sp)= ANONE;
+  deg(sp) = deg0(sp) = 2;
+  ubas(sp) = 0;
+  kt(sp) = KSPH;
+  ker(sp) = WTCUB;
+  fam(sp) = 64+TGAUS;
+  link(sp)= LDEFAU;
+  npar(sp) = calcp(sp,lfd->d);
+}
+
+void deriv_init(dv)
+deriv *dv;
+{ dv->nd = 0;
+}
+
+int des_reqd(n,p)
+int n, p;
+{
+  return(n*(p+5)+2*p*p+4*p + jac_reqd(p));
+}
+int des_reqi(n,p)
+int n, p;
+{ return(n+p);
+}
+ 
+void des_init(des,n,p)
+design *des;
+int n, p;
+{ double *z;
+  int k;
+
+  if (n<=0) WARN(("des_init: n <= 0"));
+  if (p<=0) WARN(("des_init: p <= 0"));
+
+  if (des->des_init_id != DES_INIT_ID)
+  { des->lwk = des->lind = 0;
+    des->des_init_id = DES_INIT_ID;
+  }
+
+  k = des_reqd(n,p);
+  if (k>des->lwk)
+  { des->wk = (double *)calloc(k,sizeof(double));
+    if ( des->wk == NULL ) {
+      printf("Problem allocating memory for des->wk\n");fflush(stdout);
+    }
+    des->lwk = k;
+  }
+  z = des->wk;
+
+  des->X = z; z += n*p;
+  des->w = z; z += n;
+  des->res=z; z += n;
+  des->di =z; z += n;
+  des->th =z; z += n;
+  des->wd =z; z += n;
+  des->V  =z; z += p*p;
+  des->P  =z; z += p*p;
+  des->f1 =z; z += p;
+  des->ss =z; z += p;
+  des->oc =z; z += p;
+  des->cf =z; z += p;
+ 
+  z = jac_alloc(&des->xtwx,p,z);
+ 
+  k = des_reqi(n,p);
+  if (k>des->lind)
+  {
+    des->ind = (int *)calloc(k,sizeof(int));
+    if ( des->ind == NULL ) {
+      printf("Problem allocating memory for des->ind\n");fflush(stdout);
+    }
+    des->lind = k;
+  }
+  des->fix = &des->ind[n];
+  for (k=0; k<p; k++) des->fix[k] = 0;
+
+  des->n = n; des->p = p;
+  des->smwt = n;
+  des->xtwx.p = p;                                                              
+}
+
+void deschk(des,n,p)
+design *des;
+int n, p;
+{ WARN(("deschk deprecated - use des_init()"));
+  des_init(des,n,p);
+}
+
+int likereg(coef, lk0, f1, Z)
+double *coef, *lk0, *f1, *Z;
+{ int i, ii, j, p;
+  double lk, ww, link[LLEN], *X;
+
+  if (lf_debug>2) mut_printf("  likereg: %8.5f\n",coef[0]);
+  lf_status = LF_OK;
+  lk = 0.0; p = lf_des->p;
+  setzero(Z,p*p);
+  setzero(f1,p);
+  for (i=0; i<lf_des->n; i++)
+  {
+    ii = lf_des->ind[i];
+    X = d_xi(lf_des,ii);
+    fitv(lf_des,ii) = base(lf_lfd,ii)+innerprod(coef,X,p);
+    lf_status = stdlinks(link,lf_lfd,lf_sp,ii,fitv(lf_des,ii),robscale);
+    if (lf_status == LF_BADP)
+    { *lk0 = -1.0e300;
+      return(NR_REDUCE);
+    }
+    if (lf_error) lf_status = LF_ERR;
+    if (lf_status != LF_OK) return(NR_BREAK);
+
+    ww = wght(lf_des,ii);
+    lk += ww*link[ZLIK];
+    for (j=0; j<p; j++)
+      f1[j] += X[j]*ww*link[ZDLL];
+    addouter(Z, X, X, p, ww*link[ZDDLL]);
+  }
+  for (i=0; i<p; i++) if (lf_des->fix[i])
+  { for (j=0; j<p; j++) Z[i*p+j] = Z[j*p+i] = 0.0;
+    Z[i*p+i] = 1.0;
+    f1[i] = 0.0;
+  }
+
+  if (lf_debug>4) prresp(coef,Z,p);
+  if (lf_debug>3) mut_printf("  likelihood: %8.5f\n",lk);
+  *lk0 = lf_des->llk = lk;
+
+  lf_status = fami(lf_sp)->pcheck(lf_sp,lf_des,lf_lfd);
+  switch(lf_status)
+  { case LF_DONE: return(NR_BREAK);
+    case LF_OOB:  return(NR_REDUCE);
+    case LF_PF:   return(NR_REDUCE);
+    case LF_NSLN: return(NR_BREAK);
+  }
+
+  return(NR_OK);
+}
+
+int reginit(lfd,des,sp)
+lfdata *lfd;
+design *des;
+smpar *sp;
+{ int i, ii;
+  double sb, link[LLEN];
+  s0 = s1 = sb = 0;
+  for (i=0; i<des->n; i++)
+  { ii = des->ind[i];
+    links(base(lfd,ii),resp(lfd,ii),fami(sp),LINIT,link,cens(lfd,ii),prwt(lfd,ii),1.0);
+    s1 += wght(des,ii)*link[ZDLL];
+    s0 += wght(des,ii)*prwt(lfd,ii);
+    sb += wght(des,ii)*prwt(lfd,ii)*base(lfd,ii);
+  }
+  if (s0==0) return(LF_NOPT); /* no observations with W>0 */
+  setzero(des->cf,des->p);
+  lf_tol = 1.0e-6*s0;
+  switch(link(sp))
+  { case LIDENT:
+      des->cf[0] = (s1-sb)/s0;
+      return(LF_OK);
+    case LLOG:
+      if (s1<=0.0)
+      { des->cf[0] = -1000;
+        return(LF_INFA);
+      }
+      des->cf[0] = log(s1/s0) - sb/s0;
+      return(LF_OK);
+    case LLOGIT:
+      if (s1<=0.0)
+      { des->cf[0] = -1000;
+        return(LF_INFA);
+      }
+      if (s1>=s0)
+      { des->cf[0] = 1000;
+        return(LF_INFA);
+      }
+      des->cf[0] = logit(s1/s0)-sb/s0;
+      return(LF_OK);
+    case LINVER:
+      if (s1<=0.0)
+      { des->cf[0] = 1e100;
+        return(LF_INFA);
+      }
+      des->cf[0] = s0/s1-sb/s0;
+      return(LF_OK);
+    case LSQRT:
+      des->cf[0] = sqrt(s1/s0)-sb/s0;
+      return(LF_OK);
+    case LASIN:
+      des->cf[0] = asin(sqrt(s1/s0))-sb/s0;
+      return(LF_OK);
+    default:
+      LERR(("reginit: invalid link %d",link(sp)));
+      return(LF_ERR);
+  }
+}
+
+int lfinit(lfd,sp,des)
+lfdata *lfd;
+smpar *sp;
+design *des;
+{ int initstat;
+  des->xtwx.sm = (deg0(sp)<deg(sp)) ? JAC_CHOL : JAC_EIGD;
+
+  designmatrix(lfd,sp,des);
+  setfamily(sp);
+  initstat = fami(sp)->initial(lfd,des,sp);
+
+  return(initstat);
+}
+
+void lfiter(lfd,sp,des,maxit)
+lfdata *lfd;
+smpar *sp;
+design *des;
+int maxit;
+{ int err;
+  if (lf_debug>1) mut_printf(" lfiter: %8.5f\n",des->cf[0]);
+
+  lf_des = des;
+  lf_lfd = lfd;
+  lf_sp  = sp;
+
+  max_nr(fami(sp)->like, des->cf, des->oc, des->res, des->f1,
+    &des->xtwx, des->p, maxit, lf_tol, &err);
+  switch(err)
+  { case NR_OK: return;
+    case NR_NCON:
+      WARN(("max_nr not converged"));
+      return;
+    case NR_NDIV:
+      WARN(("max_nr reduction problem"));
+      return;
+  }
+  WARN(("max_nr return status %d",err));
+}
+
+int use_robust_scale(int tg)
+{ if ((tg&64)==0) return(0); /* not quasi - no scale */
+  if (((tg&128)==0) & (((tg&63)!=TROBT) & ((tg&63)!=TCAUC))) return(0);
+  return(1);
+}
+
+/*
+ * noit not really needed any more, since
+ * gauss->pcheck returns LF_DONE, and likereg NR_BREAK
+ * in gaussian case.
+ * nb: 0/1: does local neighborhood and weights need computing?
+ * cv: 0/1: is variance/covariance matrix needed?
+ */
+int locfit(lfd,des,sp,noit,nb,cv)
+lfdata *lfd;
+design *des;
+smpar *sp;
+int noit, nb, cv;
+{ int i;
+
+  if (des->xev==NULL)
+  { LERR(("locfit: NULL evaluation point?"));
+    return(246);
+  }
+
+  if (lf_debug>0)
+  { mut_printf("locfit: ");
+    for (i=0; i<lfd->d; i++) mut_printf(" %10.6f",des->xev[i]);
+    mut_printf("\n");
+  }
+
+/* the 1e-12 avoids problems that can occur with roundoff */
+  if (nb) nbhd(lfd,des,(int)(lfd->n*nn(sp)+1e-12),0,sp);
+
+  lf_status = lfinit(lfd,sp,des);
+
+  if (lf_status == LF_OK)
+  { if (use_robust_scale(fam(sp)))
+      lf_robust(lfd,sp,des,lf_maxit);
+    else
+    { if ((fam(sp)&63)==TQUANT)
+        lfquantile(lfd,sp,des,lf_maxit);
+      else
+      { robscale = 1.0;
+        lfiter(lfd,sp,des,lf_maxit);
+      }
+    }
+  }
+
+  if (lf_status == LF_DONE) lf_status = LF_OK;
+  if (lf_status == LF_OOB) lf_status = LF_OK;
+
+  if ((fam(sp)&63)==TDEN) /* convert from rate to density */
+  { switch(link(sp))
+    { case LLOG:
+        des->cf[0] -= log(des->smwt);
+        break;
+      case LIDENT:
+        multmatscal(des->cf,1.0/des->smwt,des->p);
+        break;
+      default: LERR(("Density adjustment; invalid link"));
+    }
+  }
+
+  /* variance calculations, if requested */
+  if (cv)
+  { switch(lf_status)
+    { case LF_PF:  /* for these cases, variance calc. would likely fail. */
+      case LF_NOPT:
+      case LF_NSLN:
+      case LF_INFA:
+      case LF_DEMP:
+      case LF_XOOR:
+      case LF_DNOP:
+      case LF_BADP:
+        des->llk = des->tr0 = des->tr1 = des->tr2 = 0.0;
+        setzero(des->V,des->p*des->p);
+        setzero(des->f1,des->p);
+        break;
+      default: lf_vcov(lfd,sp,des);
+    }
+  }
+
+  return(lf_status);
+}
+
+void lf_status_msg(status)
+int status;
+{ switch(status)
+{ case LF_OK: return;
+  case LF_NCON: WARN(("locfit did not converge")); return;
+  case LF_OOB: WARN(("parameters out of bounds")); return;
+  case LF_PF: WARN(("perfect fit")); return;
+  case LF_NOPT: WARN(("no points with non-zero weight")); return;
+  case LF_NSLN: WARN(("no solution")); return;
+  case LF_INFA: WARN(("initial value problem")); return;
+  case LF_DEMP: WARN(("density estimate, empty integration region")); return;
+  case LF_XOOR: WARN(("procv: fit point outside xlim region")); return;
+  case LF_DNOP: WARN(("density estimation -- insufficient points in smoothing window")); return;
+  case LF_BADP: WARN(("bad parameters")); return;
+  default: WARN(("procv: unknown return code %d",status)); return;
+} }
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *   Compute minimax weights for local regression.
+ */
+
+#include "locf.h"
+#define NR_EMPTY 834
+
+int mmsm_ct;
+
+static int debug=0;
+#define CONVTOL 1.0e-8
+#define SINGTOL 1.0e-10
+#define NR_SINGULAR 100
+
+static lfdata *mm_lfd;
+static design *mm_des;
+static double mm_gam, mmf, lb;
+static int st;
+
+double ipower(x,n) /* use for n not too large!! */
+double x;
+int n;
+{ if (n==0) return(1.0);
+  if (n<0) return(1/ipower(x,-n));
+  return(x*ipower(x,n-1));
+}
+
+double setmmwt(des,a,gam)
+design *des;
+double *a, gam;
+{ double ip, w0, w1, sw, wt;
+  int i;
+  sw = 0.0;
+  for (i=0; i<mm_lfd->n; i++)
+  { ip = innerprod(a,d_xi(des,i),des->p);
+    wt = prwt(mm_lfd,i);
+    w0 = ip - gam*des->wd[i];
+    w1 = ip + gam*des->wd[i];
+    wght(des,i) = 0.0;
+    if (w0>0) { wght(des,i) = w0; sw += wt*w0*w0; }
+    if (w1<0) { wght(des,i) = w1; sw += wt*w1*w1; }
+  }
+  return(sw/2-a[0]);
+}
+
+/* compute sum_{w!=0} AA^T; e1-sum wA  */
+int mmsums(des,coef,f,z,J)
+design *des;
+double *coef, *f, *z;
+jacobian *J;
+{ int ct, i, j, p, sing;
+  double *A;
+
+mmsm_ct++;
+  A = J->Z;
+  *f = setmmwt(des,coef,mm_gam);
+
+  p = des->p;
+  setzero(A,p*p);
+  setzero(z,p);
+  z[0] = 1.0;
+  ct = 0;
+
+  for (i=0; i<mm_lfd->n; i++)
+    if (wght(des,i)!=0.0)
+    { addouter(A,d_xi(des,i),d_xi(des,i),p,prwt(mm_lfd,i));
+      for (j=0; j<p; j++) z[j] -= prwt(mm_lfd,i)*wght(des,i)*d_xij(des,i,j);
+      ct++;
+    }
+  if (ct==0) return(NR_EMPTY);
+
+  J->st = JAC_RAW;
+  J->p = p;
+  jacob_dec(J,JAC_EIGD);
+
+  sing = 0;
+  for (i=0; i<p; i++) sing |= (J->Z[i*p+i]<SINGTOL);
+  if ((debug) & (sing)) mut_printf("SINGULAR!!!!\n");
+
+  return((sing) ? NR_SINGULAR : NR_OK);
+}
+
+int descenddir(des,coef,dlt,f,af)
+design *des;
+double *coef, *dlt, *f;
+int af;
+{ int i, p;
+  double f0, *oc;
+
+  if (debug) mut_printf("descenddir: %8.5f %8.5f\n",dlt[0],dlt[1]);
+
+  f0 = *f;
+  oc = des->oc;
+  p = des->p;
+  memcpy(oc,coef,p*sizeof(double));
+
+  for (i=0; i<p; i++) coef[i] = oc[i]+lb*dlt[i];
+  st = mmsums(des,coef,f,des->f1,&des->xtwx);
+
+  if (*f>f0) /* halve till we drop */
+  { while (*f>f0)
+    { lb = lb/2.0;
+      for (i=0; i<p; i++) coef[i] = oc[i]+lb*dlt[i];
+      st = mmsums(des,coef,f,des->f1,&des->xtwx);
+    }
+    return(st);
+  }
+
+  if (!af) return(st);
+
+  /* double */
+  while (*f<f0)
+  { f0 = *f;
+    lb *= 2.0;
+    for (i=0; i<p; i++) coef[i] = oc[i]+lb*dlt[i];
+    st = mmsums(des,coef,f,des->f1,&des->xtwx);
+  }
+
+  lb /= 2.0;
+  for (i=0; i<p; i++) coef[i] = oc[i]+lb*dlt[i];
+  st = mmsums(des,coef,f,des->f1,&des->xtwx);
+
+  return(st);
+}
+
+int mm_initial(des)
+design *des;
+{ double *dlt;
+
+  dlt = des->ss;
+
+  setzero(des->cf,des->p);
+  st = mmsums(des,des->cf,&mmf,des->f1,&des->xtwx);
+
+  setzero(dlt,des->p);
+  dlt[0] = 1;
+  lb = 1.0;
+  st = descenddir(des,des->cf,dlt,&mmf,1);
+  return(st);
+}
+
+void getsingdir(des,dlt)
+design *des;
+double *dlt;
+{ double f, sw, c0;
+  int i, j, p, sd;
+
+  sd = -1; p = des->p;
+  setzero(dlt,p);
+  for (i=0; i<p; i++) if (des->xtwx.Z[i*p+i]<SINGTOL) sd = i;
+  if (sd==-1)
+  { mut_printf("getsingdir: nonsing?\n");
+    return;
+  }
+  if (des->xtwx.dg[sd]>0)
+    for (i=0; i<p; i++) dlt[i] = des->xtwx.Q[p*i+sd]*des->xtwx.dg[i];
+  else
+  { dlt[sd] = 1.0;
+  }
+
+  c0 = innerprod(dlt,des->f1,p);
+  if (c0<0) for (i=0; i<p; i++) dlt[i] = -dlt[i];
+}
+
+void mmax(coef, old_coef, delta, J, p, maxit, tol, err)
+double *coef, *old_coef, *delta, tol;
+int p, maxit, *err;
+jacobian *J;
+{ double old_f, lambda;
+  int i, j;
+
+  *err = NR_OK;
+ 
+  for (j=0; j<maxit; j++)
+  { memcpy(old_coef,coef,p*sizeof(double));
+    old_f = mmf;
+
+    if (st == NR_SINGULAR)
+    {
+      getsingdir(mm_des,delta);
+      st = descenddir(mm_des,coef,delta,&mmf,1);
+    }
+    if (st == NR_EMPTY)
+    { 
+      setzero(delta,p);
+      delta[0] = 1.0;
+      st = descenddir(mm_des,coef,delta,&mmf,1);
+    }
+    if (st == NR_OK)
+    { 
+      lb = 1.0;
+      jacob_solve(J,mm_des->f1);
+      memcpy(delta,mm_des->f1,p*sizeof(double));
+      st = descenddir(mm_des,coef,delta,&mmf,0);
+    }
+
+    if ((j>0) & (fabs(mmf-old_f)<tol)) return;
+  }
+  WARN(("findab not converged"));
+  *err = NR_NCON;
+  return;
+}
+
+double findab(gam)
+double gam;
+{ double sl;
+  int i, p, nr_stat;
+
+  if (debug) mut_printf("  findab: gam %8.5f\n",gam);
+  mm_gam = gam;
+  p = mm_des->p;
+  lb = 1.0;
+  st = mm_initial(mm_des);
+
+    mmax(mm_des->cf, mm_des->oc, mm_des->ss,
+       &mm_des->xtwx, p, lf_maxit, CONVTOL, &nr_stat);
+
+  sl = 0.0;
+  for (i=0; i<mm_lfd->n; i++) sl += fabs(wght(mm_des,i))*mm_des->wd[i];
+
+  if (debug) mut_printf("  sl %8.5f  gam %8.5f    %8.5f %d\n", sl,gam,sl-gam,nr_stat);
+  return(sl-gam);
+}
+
+double weightmm(coef,di,ff,gam)
+double *coef, di, *ff, gam;
+{ double y1, y2, ip;
+  ip = innerprod(ff,coef,mm_des->p);
+  y1 = ip-gam*di; if (y1>0) return(y1/ip);
+  y2 = ip+gam*di; if (y2<0) return(y2/ip);
+  return(0.0);
+}
+
+double minmax(lfd,des,sp)
+lfdata *lfd;
+design *des;
+smpar *sp;
+{ double h, u[MXDIM], gam;
+  int i, j, m, d1, p1, err_flag;
+
+  if (debug) mut_printf("minmax: x %8.5f\n",des->xev[0]);
+  mm_lfd = lfd;
+  mm_des = des;
+
+mmsm_ct = 0;
+  d1 = deg(sp)+1;
+  p1 = factorial(d1);
+  for (i=0; i<lfd->n; i++)
+  { for (j=0; j<lfd->d; j++) u[j] = datum(lfd,j,i);
+    des->wd[i] = sp->nn/p1*ipower(dist(des,i),d1);
+    des->ind[i] = i;
+    fitfun(lfd, sp, u,des->xev,d_xi(des,i),NULL);
+  }
+
+/* find gamma (i.e. solve eqn 13.17 from book), using the secant method.
+ * As a side effect, this finds the other minimax coefficients.
+ * Note that 13.17 is rewritten as
+ *   g2 = sum |l_i(x)| (||xi-x||^(p+1) M/(s*(p+1)!))
+ * where g2 = gamma * s * (p+1)! / M. The gam variable below is g2.
+ * The smoothing parameter is sp->nn == M/s.
+ */
+  gam = solve_secant(findab, 0.0, 0.0,1.0, 0.0000001, BDF_EXPRIGHT, &err_flag);
+
+/*
+ * Set the smoothing weights, in preparation for the actual fit.
+ */
+  h = 0.0; m = 0;
+  for (i=0; i<lfd->n; i++)
+  { wght(des,i) = weightmm(des->cf, des->wd[i],d_xi(des,i),gam);
+    if (wght(des,i)>0)
+    { if (dist(des,i)>h) h = dist(des,i);
+      des->ind[m] = i;
+      m++;
+    }
+  }
+  des->n = m;
+  return(h);
+}
+/*
+ * Copyright 1996-2006 Catherine Loader.
+ */
+/*
+ *
+ *  Defines the weight functions and related quantities used
+ *  in LOCFIT.
+ */
+
+#include "locf.h"
+
+/*
+ * convert kernel and kernel type strings to numeric codes.
+ */
+#define NWFUNS 13
+static char *wfuns[NWFUNS] = {
+  "rectangular", "epanechnikov", "bisquare",    "tricube",
+  "triweight",   "gaussian",     "triangular",  "ququ",
+  "6cub",        "minimax",      "exponential", "maclean", "parametric" };
+static int wvals[NWFUNS] = { WRECT, WEPAN, WBISQ, WTCUB,
+  WTRWT, WGAUS, WTRIA, WQUQU, W6CUB, WMINM, WEXPL, WMACL, WPARM };
+int lfkernel(char *z)
+{ return(pmatch(z, wfuns, wvals, NWFUNS, WTCUB));
+}
+
+#define NKTYPE 5
+static char *ktype[NKTYPE] = { "spherical", "product", "center", "lm", "zeon" };
+static int   kvals[NKTYPE] = { KSPH, KPROD, KCE, KLM, KZEON };
+int lfketype(char *z)
+{ return(pmatch(z, ktype, kvals, NKTYPE, KSPH));
+}
+
+/* The weight functions themselves.  Used everywhere. */
+double W(u,ker)
+double u;
+int ker;
+{ u = fabs(u);
+  switch(ker)
+  { case WRECT: return((u>1) ? 0.0 : 1.0);
+    case WEPAN: return((u>1) ? 0.0 : 1-u*u);
+    case WBISQ: if (u>1) return(0.0);
+                u = 1-u*u; return(u*u);
+    case WTCUB: if (u>1) return(0.0);
+                u = 1-u*u*u; return(u*u*u);
+    case WTRWT: if (u>1) return(0.0);
+                u = 1-u*u; return(u*u*u);
+    case WQUQU: if (u>1) return(0.0);
+                u = 1-u*u; return(u*u*u*u);
+    case WTRIA: if (u>1) return(0.0);
+                return(1-u);
+    case W6CUB: if (u>1) return(0.0);
+                u = 1-u*u*u; u = u*u*u; return(u*u);
+    case WGAUS: return(exp(-SQR(GFACT*u)/2.0));
+    case WEXPL: return(exp(-EFACT*u));
+    case WMACL: return(1/((u+1.0e-100)*(u+1.0e-100)));
+    case WMINM: LERR(("WMINM in W"));
+                return(0.0);
+    case WPARM: return(1.0);
+  }
+  LERR(("W(): Unknown kernel %d\n",ker));
+  return(1.0);
+}
+
+int iscompact(ker)
+int ker;
+{ if ((ker==WEXPL) | (ker==WGAUS) | (ker==WMACL) | (ker==WPARM)) return(0);
+  return(1);
+}
+
+double weightprod(lfd,u,h,ker)
+lfdata *lfd;
+double *u, h;
+int ker;
+{ int i;
+  double sc, w;
+  w = 1.0;
+  for (i=0; i<lfd->d; i++)
+  { sc = lfd->sca[i];
+    switch(lfd->sty[i])
+    { case STLEFT:
+        if (u[i]>0) return(0.0);
+        w *= W(-u[i]/(h*sc),ker);
+        break;
+      case STRIGH:
+        if (u[i]<0) return(0.0);
+        w *= W(u[i]/(h*sc),ker);
+        break;
+      case STANGL:
+        w *= W(2*fabs(sin(u[i]/(2*sc)))/h,ker);
+        break;
+      case STCPAR:
+        break;
+      default:
+        w *= W(fabs(u[i])/(h*sc),ker);
+    }
+    if (w==0.0) return(w);
+  }
+  return(w);
+}
+
+double weightsph(lfd,u,h,ker, hasdi,di)
+lfdata *lfd;
+double *u, h, di;
+int ker, hasdi;
+{ int i;
+
+  if (!hasdi) di = rho(u,lfd->sca,lfd->d,KSPH,lfd->sty);
+
+  for (i=0; i<lfd->d; i++)
+  { if ((lfd->sty[i]==STLEFT) && (u[i]>0.0)) return(0.0);
+    if ((lfd->sty[i]==STRIGH) && (u[i]<0.0)) return(0.0);
+  }
+  if (h==0) return((di==0.0) ? 1.0 : 0.0);
+
+  return(W(di/h,ker));
+}
+
+double weight(lfd,sp,x,t,h, hasdi,di)
+lfdata *lfd;
+smpar *sp;
+double *x, *t, h, di;
+int hasdi;
+{ double u[MXDIM];
+  int i;
+  for (i=0; i<lfd->d; i++) u[i] = (t==NULL) ? x[i] : x[i]-t[i];
+  switch(kt(sp))
+  { case KPROD: return(weightprod(lfd,u,h,ker(sp)));
+    case KSPH:  return(weightsph(lfd,u,h,ker(sp), hasdi,di));
+  }
+  LERR(("weight: unknown kernel type %d",kt(sp)));
+  return(1.0);
+}
+
+double sgn(x)
+double x;
+{ if (x>0) return(1.0);
+  if (x<0) return(-1.0);
+  return(0.0);
+}
+
+double WdW(u,ker) /* W'(u)/W(u) */
+double u;
+int ker;
+{ double eps=1.0e-10;
+  if (ker==WGAUS) return(-GFACT*GFACT*u);
+  if (ker==WPARM) return(0.0);
+  if (fabs(u)>=1) return(0.0);
+  switch(ker)
+  { case WRECT: return(0.0);
+    case WTRIA: return(-sgn(u)/(1-fabs(u)+eps));
+    case WEPAN: return(-2*u/(1-u*u+eps));
+    case WBISQ: return(-4*u/(1-u*u+eps));
+    case WTRWT: return(-6*u/(1-u*u+eps));
+    case WTCUB: return(-9*sgn(u)*u*u/(1-u*u*fabs(u)+eps));
+    case WEXPL: return((u>0) ? -EFACT : EFACT);
+  }
+  LERR(("WdW: invalid kernel"));
+  return(0.0);
+}
+
+/* deriv. weights .. spherical, product etc
+   u, sc, sty needed only in relevant direction
+   Acutally, returns (d/dx W(||x||/h) ) / W(.)
+*/
+double weightd(u,sc,d,ker,kt,h,sty,di)
+double u, sc, h, di;
+int d, ker, kt, sty;
+{ if (sty==STANGL)
+  { if (kt==KPROD)
+      return(-WdW(2*sin(u/(2*sc)),ker)*cos(u/(2*sc))/(h*sc));
+    if (di==0.0) return(0.0);
+    return(-WdW(di/h,ker)*sin(u/sc)/(h*sc*di));
+  }
+  if (sty==STCPAR) return(0.0);
+  if (kt==KPROD)
+    return(-WdW(u/(h*sc),ker)/(h*sc));
+  if (di==0.0) return(0.0);
+  return(-WdW(di/h,ker)*u/(h*di*sc*sc));
+}
+
+double weightdd(u,sc,d,ker,kt,h,sty,di,i0,i1)
+double *u, *sc, h, di;
+int d, ker, kt, i0, i1, *sty;
+{ double w;
+  w = 1;
+  if (kt==KPROD)
+  {
+    w = WdW(u[i0]/(h*sc[i0]),ker)*WdW(u[i1]/(h*sc[i1]),ker)/(h*h*sc[i0]*sc[i1]);
+  }
+  return(0.0);
+}
+
+/* Derivatives W'(u)/u.
+   Used in simult. conf. band computations,
+   and kernel density bandwidth selectors. */
+double Wd(u,ker)
+double u;
+int ker;
+{ double v;
+  if (ker==WGAUS) return(-SQR(GFACT)*exp(-SQR(GFACT*u)/2));
+  if (ker==WPARM) return(0.0);
+  if (fabs(u)>1) return(0.0);
+  switch(ker)
+  { case WEPAN: return(-2.0);
+    case WBISQ: return(-4*(1-u*u));
+    case WTCUB: v = 1-u*u*u;
+                return(-9*v*v*u);
+    case WTRWT: v = 1-u*u;
+                return(-6*v*v);
+    default: LERR(("Invalid kernel %d in Wd",ker));
+  }
+  return(0.0);
+}
+
+/* Second derivatives W''(u)-W'(u)/u.
+   used in simult. conf. band computations in >1 dimension. */
+double Wdd(u,ker)
+double u;
+int ker;
+{ double v;
+  if (ker==WGAUS) return(SQR(u*GFACT*GFACT)*exp(-SQR(u*GFACT)/2));
+  if (ker==WPARM) return(0.0);
+  if (u>1) return(0.0);
+  switch(ker)
+  { case WBISQ: return(12*u*u);
+    case WTCUB: v = 1-u*u*u;
+                return(-9*u*v*v+54*u*u*u*u*v);
+    case WTRWT: return(24*u*u*(1-u*u));
+    default: LERR(("Invalid kernel %d in Wdd",ker));
+  }
+  return(0.0);
+}
+
+/* int u1^j1..ud^jd W(u) du.
+   Used for local log-linear density estimation.
+   Assume all j_i are even.
+   Also in some bandwidth selection.
+*/
+double wint(d,j,nj,ker)
+int d, *j, nj, ker;
+{ double I, z;
+  int k, dj;
+  dj = d;
+  for (k=0; k<nj; k++) dj += j[k];
+  switch(ker) /* int_0^1 u^(dj-1) W(u)du  */
+  { case WRECT: I = 1.0/dj; break;
+    case WEPAN: I = 2.0/(dj*(dj+2)); break;
+    case WBISQ: I = 8.0/(dj*(dj+2)*(dj+4)); break;
+    case WTCUB: I = 162.0/(dj*(dj+3)*(dj+6)*(dj+9)); break;
+    case WTRWT: I = 48.0/(dj*(dj+2)*(dj+4)*(dj+6)); break;
+    case WTRIA: I = 1.0/(dj*(dj+1)); break;
+    case WQUQU: I = 384.0/(dj*(dj+2)*(dj+4)*(dj+6)*(dj+8)); break;
+    case W6CUB: I = 524880.0/(dj*(dj+3)*(dj+6)*(dj+9)*(dj+12)*(dj+15)*(dj+18)); break;
+    case WGAUS: switch(d)
+                { case 1: I = S2PI/GFACT; break;
+                  case 2: I = 2*PI/(GFACT*GFACT); break;
+                  default: I = exp(d*log(S2PI/GFACT)); /* for nj=0 */
+                }
+                for (k=0; k<nj; k++) /* deliberate drop */
+                  switch(j[k])
+                  { case 4: I *= 3.0/(GFACT*GFACT);
+                    case 2: I /= GFACT*GFACT;
+                  }
+                return(I);
+    case WEXPL: I = factorial(dj-1)/ipower(EFACT,dj); break;
+    default: LERR(("Unknown kernel %d in exacint",ker));
+  }
+  if ((d==1) && (nj==0)) return(2*I); /* common case quick */
+  z = (d-nj)*LOGPI/2-mut_lgammai(dj);
+  for (k=0; k<nj; k++) z += mut_lgammai(j[k]+1);
+  return(2*I*exp(z));
+}
+
+/* taylor series expansion of weight function around x.
+   0 and 1 are common arguments, so are worth programming
+   as special cases.
+   Used in density estimation.
+*/
+int wtaylor(f,x,ker)
+double *f, x;
+int ker;
+{ double v;
+  switch(ker)
+  { case WRECT:
+      f[0] = 1.0;
+      return(1);
+    case WEPAN:
+      f[0] = 1-x*x; f[1] = -2*x; f[2] = -1;
+      return(3);
+    case WBISQ:
+      v = 1-x*x;
+      f[0] = v*v;   f[1] = -4*x*v; f[2] = 4-6*v;
+      f[3] = 4*x;   f[4] = 1;
+      return(5);
+    case WTCUB:
+      if (x==1.0)
+      { f[0] = f[1] = f[2] = 0; f[3] = -27; f[4] = -81; f[5] = -108;
+        f[6] = -81; f[7] = -36; f[8] = -9; f[9] = -1; return(10); }
+      if (x==0.0)
+      { f[1] = f[2] = f[4] = f[5] = f[7] = f[8] = 0;
+        f[0] = 1; f[3] = -3; f[6] = 3; f[9] = -1; return(10); }
+      v = 1-x*x*x;
+      f[0] = v*v*v; f[1] = -9*v*v*x*x; f[2] = x*v*(27-36*v);
+      f[3] = -27+v*(108-84*v);         f[4] = -3*x*x*(27-42*v);
+      f[5] = x*(-108+126*v);           f[6] = -81+84*v;
+      f[7] = -36*x*x; f[8] = -9*x;     f[9] = -1;
+      return(10);
+    case WTRWT:
+      v = 1-x*x;
+      f[0] = v*v*v; f[1] = -6*x*v*v; f[2] = v*(12-15*v);
+      f[3] = x*(20*v-8); f[4] = 15*v-12; f[5] = -6; f[6] = -1;
+      return(7);
+    case WTRIA:
+      f[0] = 1-x; f[1] = -1;
+      return(2);
+    case WQUQU:
+      v = 1-x*x;
+      f[0] = v*v*v*v; f[1] = -8*x*v*v*v; f[2] = v*v*(24-28*v);
+      f[3] = v*x*(56*v-32); f[4] = (70*v-80)*v+16; f[5] = x*(32-56*v);
+      f[6] = 24-28*v; f[7] = 8*x; f[8] = 1;
+      return(9);
+    case W6CUB:
+      v = 1-x*x*x;
+      f[0] = v*v*v*v*v*v;
+      f[1] = -18*x*x*v*v*v*v*v;
+      f[2] = x*v*v*v*v*(135-153*v);
+      f[3] = v*v*v*(-540+v*(1350-816*v));
+      f[4] = x*x*v*v*(1215-v*(4050-v*3060));
+      f[5] = x*v*(-1458+v*(9234+v*(-16254+v*8568)));
+      f[6] = 729-v*(10206-v*(35154-v*(44226-v*18564)));
+      f[7] = x*x*(4374-v*(30132-v*(56862-v*31824)));
+      f[8] = x*(12393-v*(61479-v*(92664-v*43758)));
+      f[9] = 21870-v*(89100-v*(115830-v*48620));
+      f[10]= x*x*(26730-v*(69498-v*43758));
+      f[11]= x*(23814-v*(55458-v*31824));
+      f[12]= 15849-v*(34398-v*18564);
+      f[13]= x*x*(7938-8568*v);
+      f[14]= x*(2970-3060*v);
+      f[15]= 810-816*v;
+      f[16]= 153*x*x;
+      f[17]= 18*x;
+      f[18]= 1;
+      return(19);
+  }
+  LERR(("Invalid kernel %d in wtaylor",ker));
+  return(0);
+}
+
+/* convolution int W(x)W(x+v)dx.
+   used in kde bandwidth selection.
+*/
+double Wconv(v,ker)
+double v;
+int ker;
+{ double v2;
+  switch(ker)
+  { case WGAUS: return(SQRPI/GFACT*exp(-SQR(GFACT*v)/4));
+    case WRECT:
+      v = fabs(v);
+      if (v>2) return(0.0);
+      return(2-v);
+    case WEPAN:
+      v = fabs(v);
+      if (v>2) return(0.0);
+      return((2-v)*(16+v*(8-v*(16-v*(2+v))))/30);
+    case WBISQ:
+      v = fabs(v);
+      if (v>2) return(0.0);
+      v2 = 2-v;
+      return(v2*v2*v2*v2*v2*(16+v*(40+v*(36+v*(10+v))))/630);
+  }
+  LERR(("Wconv not implemented for kernel %d",ker));
+  return(0.0);
+}
+
+/* derivative of Wconv.
+   1/v d/dv int W(x)W(x+v)dx
+   used in kde bandwidth selection.
+*/
+double Wconv1(v,ker)
+double v;
+int ker;
+{ double v2;
+  v = fabs(v);
+  switch(ker)
+  { case WGAUS: return(-0.5*SQRPI*GFACT*exp(-SQR(GFACT*v)/4));
+    case WRECT:
+      if (v>2) return(0.0);
+      return(1.0);
+    case WEPAN:
+      if (v>2) return(0.0);
+      return((-16+v*(12-v*v))/6);
+    case WBISQ:
+      if (v>2) return(0.0);
+      v2 = 2-v;
+      return(-v2*v2*v2*v2*(32+v*(64+v*(24+v*3)))/210);
+  }
+  LERR(("Wconv1 not implemented for kernel %d",ker));
+  return(0.0);
+}
+
+/* 4th derivative of Wconv.
+   used in kde bandwidth selection (BCV, SJPI, GKK)
+*/
+double Wconv4(v,ker)
+double v;
+int ker;
+{ double gv;
+  switch(ker)
+  { case WGAUS:
+      gv = GFACT*v;
+      return(exp(-SQR(gv)/4)*GFACT*GFACT*GFACT*(12-gv*gv*(12-gv*gv))*SQRPI/16);
+  }
+  LERR(("Wconv4 not implemented for kernel %d",ker));
+  return(0.0);
+}
+
+/* 5th derivative of Wconv.
+   used in kde bandwidth selection (BCV method only)
+*/
+double Wconv5(v,ker) /* (d/dv)^5 int W(x)W(x+v)dx */
+double v;
+int ker;
+{ double gv;
+  switch(ker)
+  { case WGAUS:
+      gv = GFACT*v;
+      return(-exp(-SQR(gv)/4)*GFACT*GFACT*GFACT*GFACT*gv*(60-gv*gv*(20-gv*gv))*SQRPI/32);
+  }
+  LERR(("Wconv5 not implemented for kernel %d",ker));
+  return(0.0);
+}
+
+/* 6th derivative of Wconv.
+   used in kde bandwidth selection (SJPI)
+*/
+double Wconv6(v,ker)
+double v;
+int ker;
+{ double gv, z;
+  switch(ker)
+  { case WGAUS:
+      gv = GFACT*v;
+      gv = gv*gv;
+      z = exp(-gv/4)*(-120+gv*(180-gv*(30-gv)))*0.02769459142;
+      gv = GFACT*GFACT;
+      return(z*gv*gv*GFACT);
+  }
+  LERR(("Wconv6 not implemented for kernel %d",ker));
+  return(0.0);
+}
+
+/* int W(v)^2 dv / (int v^2 W(v) dv)^2
+   used in some bandwidth selectors
+*/
+double Wikk(ker,deg)
+int ker, deg;
+{ switch(deg)
+  { case 0:
+    case 1: /* int W(v)^2 dv / (int v^2 W(v) dv)^2 */
+      switch(ker)
+      { case WRECT: return(4.5);
+        case WEPAN: return(15.0);
+        case WBISQ: return(35.0);
+        case WGAUS: return(0.2820947918*GFACT*GFACT*GFACT*GFACT*GFACT);
+        case WTCUB: return(34.152111046847892);   /* 59049 / 1729 */
+        case WTRWT: return(66.083916083916080);   /* 9450/143 */
+      }
+    case 2:
+    case 3: /* 4!^2/8*int(W1^2)/int(v^4W1)^2
+               W1=W*(n4-v^2n2)/(n0n4-n2n2) */
+      switch(ker)
+      { case WRECT: return(11025.0);
+        case WEPAN: return(39690.0);
+        case WBISQ: return(110346.9231);
+        case WGAUS: return(14527.43412);
+        case WTCUB: return(126500.5904);
+        case WTRWT: return(254371.7647);
+      }
+  }
+  LERR(("Wikk not implemented for kernel %d, deg %d",ker,deg));
+  return(0.0);
+}