### view env/lib/python3.9/site-packages/networkx/generators/tests/test_nonisomorphic_trees.py @ 0:4f3585e2f14bdraftdefaulttip

author shellac Mon, 22 Mar 2021 18:12:50 +0000
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"""
====================
Generators - Non Isomorphic Trees
====================

Unit tests for WROM algorithm generator in generators/nonisomorphic_trees.py
"""
import networkx as nx
from networkx.testing import assert_edges_equal

class TestGeneratorNonIsomorphicTrees:
def test_tree_structure(self):
# test for tree structure for nx.nonisomorphic_trees()
def f(x):
return list(nx.nonisomorphic_trees(x))

for i in f(6):
assert nx.is_tree(i)
for i in f(8):
assert nx.is_tree(i)

def test_nonisomorphism(self):
# test for nonisomorphism of trees for nx.nonisomorphic_trees()
def f(x):
return list(nx.nonisomorphic_trees(x))

trees = f(6)
for i in range(len(trees)):
for j in range(i + 1, len(trees)):
assert not nx.is_isomorphic(trees[i], trees[j])
trees = f(8)
for i in range(len(trees)):
for j in range(i + 1, len(trees)):
assert not nx.is_isomorphic(trees[i], trees[j])

def test_number_of_nonisomorphic_trees(self):
# http://oeis.org/A000055
assert nx.number_of_nonisomorphic_trees(2) == 1
assert nx.number_of_nonisomorphic_trees(3) == 1
assert nx.number_of_nonisomorphic_trees(4) == 2
assert nx.number_of_nonisomorphic_trees(5) == 3
assert nx.number_of_nonisomorphic_trees(6) == 6
assert nx.number_of_nonisomorphic_trees(7) == 11
assert nx.number_of_nonisomorphic_trees(8) == 23

def test_nonisomorphic_trees(self):
def f(x):
return list(nx.nonisomorphic_trees(x))

assert_edges_equal(f(3)[0].edges(), [(0, 1), (0, 2)])
assert_edges_equal(f(4)[0].edges(), [(0, 1), (0, 3), (1, 2)])
assert_edges_equal(f(4)[1].edges(), [(0, 1), (0, 2), (0, 3)])

def test_nonisomorphic_trees_matrix(self):
trees_2 = [[[0, 1], [1, 0]]]
assert list(nx.nonisomorphic_trees(2, create="matrix")) == trees_2
trees_3 = [[[0, 1, 1], [1, 0, 0], [1, 0, 0]]]
assert list(nx.nonisomorphic_trees(3, create="matrix")) == trees_3
trees_4 = [
[[0, 1, 0, 1], [1, 0, 1, 0], [0, 1, 0, 0], [1, 0, 0, 0]],
[[0, 1, 1, 1], [1, 0, 0, 0], [1, 0, 0, 0], [1, 0, 0, 0]],
]
assert list(nx.nonisomorphic_trees(4, create="matrix")) == trees_4
```