comparison tools/stats/lda_analy.xml @ 0:9071e359b9a3

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author xuebing
date Fri, 09 Mar 2012 19:37:19 -0500
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1 <tool id="lda_analy1" name="Perform LDA" version="1.0.1">
2 <description>Linear Discriminant Analysis</description>
3 <command interpreter="sh">r_wrapper.sh $script_file</command>
4 <inputs>
5 <param format="tabular" name="input" type="data" label="Source file"/>
6 <param name="cond" size="30" type="integer" value="3" label="Number of principal components" help="See TIP below">
7 <validator type="empty_field" message="Enter a valid number of principal components, see syntax below for examples"/>
8 </param>
9
10 </inputs>
11 <outputs>
12 <data format="txt" name="output" />
13 </outputs>
14
15 <tests>
16 <test>
17 <param name="input" value="matrix_generator_for_pc_and_lda_output.tabular"/>
18 <output name="output" file="lda_analy_output.txt"/>
19 <param name="cond" value="2"/>
20
21 </test>
22 </tests>
23
24 <configfiles>
25 <configfile name="script_file">
26
27 rm(list = objects() )
28
29 ############# FORMAT X DATA #########################
30 format&lt;-function(data) {
31 ind=NULL
32 for(i in 1 : ncol(data)){
33 if (is.na(data[nrow(data),i])) {
34 ind&lt;-c(ind,i)
35 }
36 }
37 #print(is.null(ind))
38 if (!is.null(ind)) {
39 data&lt;-data[,-c(ind)]
40 }
41
42 data
43 }
44
45 ########GET RESPONSES ###############################
46 get_resp&lt;- function(data) {
47 resp1&lt;-as.vector(data[,ncol(data)])
48 resp=numeric(length(resp1))
49 for (i in 1:length(resp1)) {
50 if (resp1[i]=="Y ") {
51 resp[i] = 0
52 }
53 if (resp1[i]=="X ") {
54 resp[i] = 1
55 }
56 }
57 return(resp)
58 }
59
60 ######## CHARS TO NUMBERS ###########################
61 f_to_numbers&lt;- function(F) {
62 ind&lt;-NULL
63 G&lt;-matrix(0,nrow(F), ncol(F))
64 for (i in 1:nrow(F)) {
65 for (j in 1:ncol(F)) {
66 G[i,j]&lt;-as.integer(F[i,j])
67 }
68 }
69 return(G)
70 }
71
72 ###################NORMALIZING#########################
73 norm &lt;- function(M, a=NULL, b=NULL) {
74 C&lt;-NULL
75 ind&lt;-NULL
76
77 for (i in 1: ncol(M)) {
78 if (sd(M[,i])!=0) {
79 M[,i]&lt;-(M[,i]-mean(M[,i]))/sd(M[,i])
80 }
81 # else {print(mean(M[,i]))}
82 }
83 return(M)
84 }
85
86 ##### LDA DIRECTIONS #################################
87 lda_dec &lt;- function(data, k){
88 priors=numeric(k)
89 grandmean&lt;-numeric(ncol(data)-1)
90 means=matrix(0,k,ncol(data)-1)
91 B = matrix(0, ncol(data)-1, ncol(data)-1)
92 N=nrow(data)
93 for (i in 1:k){
94 priors[i]=sum(data[,1]==i)/N
95 grp=subset(data,data\$group==i)
96 means[i,]=mean(grp[,2:ncol(data)])
97 #print(means[i,])
98 #print(priors[i])
99 #print(priors[i]*means[i,])
100 grandmean = priors[i]*means[i,] + grandmean
101 }
102
103 for (i in 1:k) {
104 B= B + priors[i]*((means[i,]-grandmean)%*%t(means[i,]-grandmean))
105 }
106
107 W = var(data[,2:ncol(data)])
108 svdW = svd(W)
109 inv_sqrtW =solve(svdW\$v %*% diag(sqrt(svdW\$d)) %*% t(svdW\$v))
110 B_star= t(inv_sqrtW)%*%B%*%inv_sqrtW
111 B_star_decomp = svd(B_star)
112 directions = inv_sqrtW%*%B_star_decomp\$v
113 return( list(directions, B_star_decomp\$d) )
114 }
115
116 ################ NAIVE BAYES FOR 1D SIR OR LDA ##############
117 naive_bayes_classifier &lt;- function(resp, tr_data, test_data, k=2, tau) {
118 tr_data=data.frame(resp=resp, dir=tr_data)
119 means=numeric(k)
120 #print(k)
121 cl=numeric(k)
122 predclass=numeric(length(test_data))
123 for (i in 1:k) {
124 grp = subset(tr_data, resp==i)
125 means[i] = mean(grp\$dir)
126 #print(i, means[i])
127 }
128 cutoff = tau*means[1]+(1-tau)*means[2]
129 #print(tau)
130 #print(means)
131 #print(cutoff)
132 if (cutoff&gt;means[1]) {
133 cl[1]=1
134 cl[2]=2
135 }
136 else {
137 cl[1]=2
138 cl[2]=1
139 }
140
141 for (i in 1:length(test_data)) {
142
143 if (test_data[i] &lt;= cutoff) {
144 predclass[i] = cl[1]
145 }
146 else {
147 predclass[i] = cl[2]
148 }
149 }
150 #print(means)
151 #print(mean(means))
152 #X11()
153 #plot(test_data,pch=predclass, col=resp)
154 predclass
155 }
156
157 ################# EXTENDED ERROR RATES #################
158 ext_error_rate &lt;- function(predclass, actualclass,msg=c("you forgot the message"), pr=1) {
159 er=sum(predclass != actualclass)/length(predclass)
160
161 matr&lt;-data.frame(predclass=predclass,actualclass=actualclass)
162 escapes = subset(matr, actualclass==1)
163 subjects = subset(matr, actualclass==2)
164 er_esc=sum(escapes\$predclass != escapes\$actualclass)/length(escapes\$predclass)
165 er_subj=sum(subjects\$predclass != subjects\$actualclass)/length(subjects\$predclass)
166
167 if (pr==1) {
168 # print(paste(c(msg, 'overall : ', (1-er)*100, "%."),collapse=" "))
169 # print(paste(c(msg, 'within escapes : ', (1-er_esc)*100, "%."),collapse=" "))
170 # print(paste(c(msg, 'within subjects: ', (1-er_subj)*100, "%."),collapse=" "))
171 }
172 return(c((1-er)*100, (1-er_esc)*100, (1-er_subj)*100))
173 }
174
175 ## Main Function ##
176
177 files&lt;-matrix("${input}", 1,1, byrow=T)
178
179 d&lt;-"${cond}" # Number of PC
180
181 tau&lt;-seq(0,1, by=0.005)
182 #tau&lt;-seq(0,1, by=0.1)
183 for_curve=matrix(-10, 3,length(tau))
184
185 ##############################################################
186
187 test_data_whole_X &lt;-read.delim(files[1,1], row.names=1)
188
189 #### FORMAT TRAINING DATA ####################################
190 # get only necessary columns
191
192 test_data_whole_X&lt;-format(test_data_whole_X)
193 oligo_labels&lt;-test_data_whole_X[1:(nrow(test_data_whole_X)-1),ncol(test_data_whole_X)]
194 test_data_whole_X&lt;-test_data_whole_X[,1:(ncol(test_data_whole_X)-1)]
195
196 X_names&lt;-colnames(test_data_whole_X)[1:ncol(test_data_whole_X)]
197 test_data_whole_X&lt;-t(test_data_whole_X)
198 resp&lt;-get_resp(test_data_whole_X)
199 ldaqda_resp = resp + 1
200 a&lt;-sum(resp) # Number of Subject
201 b&lt;-length(resp) - a # Number of Escape
202 ## FREQUENCIES #################################################
203 F&lt;-test_data_whole_X[,1:(ncol(test_data_whole_X)-1)]
204 F&lt;-f_to_numbers(F)
205 FN&lt;-norm(F, a, b)
206 ss&lt;-svd(FN)
207 eigvar&lt;-NULL
208 eig&lt;-ss\$d^2
209
210 for ( i in 1:length(ss\$d)) {
211 eigvar[i]&lt;-sum(eig[1:i])/sum(eig)
212 }
213
214 #print(paste(c("Variance explained : ", eigvar[d]*100, "%"), collapse=""))
215
216 Z&lt;-F%*%ss\$v
217
218 ldaqda_data &lt;- data.frame(group=ldaqda_resp,Z[,1:d])
219 lda_dir&lt;-lda_dec(ldaqda_data,2)
220 train_lda_pred &lt;-Z[,1:d]%*%lda_dir[[1]]
221
222 ############# NAIVE BAYES CROSS-VALIDATION #############
223 ### LDA #####
224
225 y&lt;-ldaqda_resp
226 X&lt;-F
227 cv&lt;-matrix(c(rep('NA',nrow(test_data_whole_X))), nrow(test_data_whole_X), length(tau))
228 for (i in 1:nrow(test_data_whole_X)) {
229 # print(i)
230 resp&lt;-y[-i]
231 p&lt;-matrix(X[-i,], dim(X)[1]-1, dim(X)[2])
232 testdata&lt;-matrix(X[i,],1,dim(X)[2])
233 p1&lt;-norm(p)
234 sss&lt;-svd(p1)
235 pred&lt;-(p%*%sss\$v)[,1:d]
236 test&lt;- (testdata%*%sss\$v)[,1:d]
237 lda &lt;- lda_dec(data.frame(group=resp,pred),2)
238 pred &lt;- pred[,1:d]%*%lda[[1]][,1]
239 test &lt;- test%*%lda[[1]][,1]
240 test&lt;-matrix(test, 1, length(test))
241 for (t in 1:length(tau)) {
242 cv[i, t] &lt;- naive_bayes_classifier (resp, pred, test,k=2, tau[t])
243 }
244 }
245
246 for (t in 1:length(tau)) {
247 tr_err&lt;-ext_error_rate(cv[,t], ldaqda_resp , c("CV"), 1)
248 for_curve[1:3,t]&lt;-tr_err
249 }
250
251 dput(for_curve, file="${output}")
252
253
254 </configfile>
255 </configfiles>
256
257 <help>
258
259 .. class:: infomark
260
261 **TIP:** If you want to perform Principal Component Analysis (PCA) on the give numeric input data (which corresponds to the "Source file First in "Generate A Matrix" tool), please use *Multivariate Analysis/Principal Component Analysis*
262
263 -----
264
265 .. class:: infomark
266
267 **What it does**
268
269 This tool consists of the module to perform the Linear Discriminant Analysis as described in Carrel et al., 2006 (PMID: 17009873)
270
271 *Carrel L, Park C, Tyekucheva S, Dunn J, Chiaromonte F, et al. (2006) Genomic Environment Predicts Expression Patterns on the Human Inactive X Chromosome. PLoS Genet 2(9): e151. doi:10.1371/journal.pgen.0020151*
272
273 -----
274
275 .. class:: warningmark
276
277 **Note**
278
279 - Output from "Generate A Matrix" tool is used as input file for this tool
280 - Output of this tool contains LDA classification success rates for different values of the turning parameter tau (from 0 to 1 with 0.005 interval). This output file will be used to establish the ROC plot, and you can obtain more detail information from this plot.
281
282
283 </help>
284
285 </tool>