# ---------------------------------------------------------------------------- # Copyright (c) 2013--, scikit-bio development team. # # Distributed under the terms of the Modified BSD License. # # The full license is in the file COPYING.txt, distributed with this software. # ---------------------------------------------------------------------------- import io from unittest import TestCase, main from skbio import DistanceMatrix, TreeNode, nj from skbio.tree._nj import ( _compute_q, _compute_collapsed_dm, _lowest_index, _otu_to_new_node, _pair_members_to_new_node) class NjTests(TestCase): def setUp(self): data1 = [[0, 5, 9, 9, 8], [5, 0, 10, 10, 9], [9, 10, 0, 8, 7], [9, 10, 8, 0, 3], [8, 9, 7, 3, 0]] ids1 = list('abcde') self.dm1 = DistanceMatrix(data1, ids1) # this newick string was confirmed against http://www.trex.uqam.ca/ # which generated the following (isomorphic) newick string: # (d:2.0000,e:1.0000,(c:4.0000,(a:2.0000,b:3.0000):3.0000):2.0000); self.expected1_str = ("(d:2.000000, (c:4.000000, (b:3.000000," " a:2.000000):3.000000):2.000000, e:1.000000);") self.expected1_TreeNode = TreeNode.read( io.StringIO(self.expected1_str)) # this example was pulled from the Phylip manual # http://evolution.genetics.washington.edu/phylip/doc/neighbor.html data2 = [[0.0000, 1.6866, 1.7198, 1.6606, 1.5243, 1.6043, 1.5905], [1.6866, 0.0000, 1.5232, 1.4841, 1.4465, 1.4389, 1.4629], [1.7198, 1.5232, 0.0000, 0.7115, 0.5958, 0.6179, 0.5583], [1.6606, 1.4841, 0.7115, 0.0000, 0.4631, 0.5061, 0.4710], [1.5243, 1.4465, 0.5958, 0.4631, 0.0000, 0.3484, 0.3083], [1.6043, 1.4389, 0.6179, 0.5061, 0.3484, 0.0000, 0.2692], [1.5905, 1.4629, 0.5583, 0.4710, 0.3083, 0.2692, 0.0000]] ids2 = ["Bovine", "Mouse", "Gibbon", "Orang", "Gorilla", "Chimp", "Human"] self.dm2 = DistanceMatrix(data2, ids2) self.expected2_str = ("(Mouse:0.76891, (Gibbon:0.35793, (Orang:0.28469" ", (Gorilla:0.15393, (Chimp:0.15167, Human:0.117" "53):0.03982):0.02696):0.04648):0.42027, Bovine:" "0.91769);") self.expected2_TreeNode = TreeNode.read( io.StringIO(self.expected2_str)) data3 = [[0, 5, 4, 7, 6, 8], [5, 0, 7, 10, 9, 11], [4, 7, 0, 7, 6, 8], [7, 10, 7, 0, 5, 8], [6, 9, 6, 5, 0, 8], [8, 11, 8, 8, 8, 0]] ids3 = map(str, range(6)) self.dm3 = DistanceMatrix(data3, ids3) self.expected3_str = ("((((0:1.000000,1:4.000000):1.000000,2:2.000000" "):1.250000,5:4.750000):0.750000,3:2.750000,4:2." "250000);") self.expected3_TreeNode = TreeNode.read( io.StringIO(self.expected3_str)) # this dm can yield negative branch lengths data4 = [[0, 5, 9, 9, 800], [5, 0, 10, 10, 9], [9, 10, 0, 8, 7], [9, 10, 8, 0, 3], [800, 9, 7, 3, 0]] ids4 = list('abcde') self.dm4 = DistanceMatrix(data4, ids4) def test_nj_dm1(self): self.assertEqual(nj(self.dm1, result_constructor=str), self.expected1_str) # what is the correct way to compare TreeNode objects for equality? actual_TreeNode = nj(self.dm1) self.assertEqual(actual_TreeNode.compare_tip_distances( self.expected1_TreeNode), 0.0) def test_nj_dm2(self): actual_TreeNode = nj(self.dm2) self.assertAlmostEqual(actual_TreeNode.compare_tip_distances( self.expected2_TreeNode), 0.0) def test_nj_dm3(self): actual_TreeNode = nj(self.dm3) self.assertAlmostEqual(actual_TreeNode.compare_tip_distances( self.expected3_TreeNode), 0.0) def test_nj_zero_branch_length(self): # no nodes have negative branch length when we disallow negative # branch length. self is excluded as branch length is None tree = nj(self.dm4) for n in tree.postorder(include_self=False): self.assertTrue(n.length >= 0) # only tips associated with the large distance in the input # have positive branch lengths when we allow negative branch # length tree = nj(self.dm4, False) self.assertTrue(tree.find('a').length > 0) self.assertTrue(tree.find('b').length < 0) self.assertTrue(tree.find('c').length < 0) self.assertTrue(tree.find('d').length < 0) self.assertTrue(tree.find('e').length > 0) def test_nj_trivial(self): data = [[0, 3, 2], [3, 0, 3], [2, 3, 0]] dm = DistanceMatrix(data, list('abc')) expected_str = "(b:2.000000, a:1.000000, c:1.000000);" self.assertEqual(nj(dm, result_constructor=str), expected_str) def test_nj_error(self): data = [[0, 3], [3, 0]] dm = DistanceMatrix(data, list('ab')) self.assertRaises(ValueError, nj, dm) def test_compute_q(self): expected_data = [[0, -50, -38, -34, -34], [-50, 0, -38, -34, -34], [-38, -38, 0, -40, -40], [-34, -34, -40, 0, -48], [-34, -34, -40, -48, 0]] expected_ids = list('abcde') expected = DistanceMatrix(expected_data, expected_ids) self.assertEqual(_compute_q(self.dm1), expected) data = [[0, 3, 2], [3, 0, 3], [2, 3, 0]] dm = DistanceMatrix(data, list('abc')) # computed this manually expected_data = [[0, -8, -8], [-8, 0, -8], [-8, -8, 0]] expected = DistanceMatrix(expected_data, list('abc')) self.assertEqual(_compute_q(dm), expected) def test_compute_collapsed_dm(self): expected_data = [[0, 7, 7, 6], [7, 0, 8, 7], [7, 8, 0, 3], [6, 7, 3, 0]] expected_ids = ['x', 'c', 'd', 'e'] expected1 = DistanceMatrix(expected_data, expected_ids) self.assertEqual(_compute_collapsed_dm(self.dm1, 'a', 'b', True, 'x'), expected1) # computed manually expected_data = [[0, 4, 3], [4, 0, 3], [3, 3, 0]] expected_ids = ['yy', 'd', 'e'] expected2 = DistanceMatrix(expected_data, expected_ids) self.assertEqual( _compute_collapsed_dm(expected1, 'x', 'c', True, 'yy'), expected2) def test_lowest_index(self): self.assertEqual(_lowest_index(self.dm1), (4, 3)) self.assertEqual(_lowest_index(_compute_q(self.dm1)), (1, 0)) def test_otu_to_new_node(self): self.assertEqual(_otu_to_new_node(self.dm1, 'a', 'b', 'c', True), 7) self.assertEqual(_otu_to_new_node(self.dm1, 'a', 'b', 'd', True), 7) self.assertEqual(_otu_to_new_node(self.dm1, 'a', 'b', 'e', True), 6) def test_otu_to_new_node_zero_branch_length(self): data = [[0, 40, 3], [40, 0, 3], [3, 3, 0]] ids = ['a', 'b', 'c'] dm = DistanceMatrix(data, ids) self.assertEqual(_otu_to_new_node(dm, 'a', 'b', 'c', True), 0) self.assertEqual(_otu_to_new_node(dm, 'a', 'b', 'c', False), -17) def test_pair_members_to_new_node(self): self.assertEqual(_pair_members_to_new_node(self.dm1, 'a', 'b', True), (2, 3)) self.assertEqual(_pair_members_to_new_node(self.dm1, 'a', 'c', True), (4, 5)) self.assertEqual(_pair_members_to_new_node(self.dm1, 'd', 'e', True), (2, 1)) def test_pair_members_to_new_node_zero_branch_length(self): # the values in this example don't really make sense # (I'm not sure how you end up with these distances between # three sequences), but that doesn't really matter for the sake # of this test data = [[0, 4, 2], [4, 0, 38], [2, 38, 0]] ids = ['a', 'b', 'c'] dm = DistanceMatrix(data, ids) self.assertEqual(_pair_members_to_new_node(dm, 'a', 'b', True), (0, 4)) # this makes it clear why negative branch lengths don't make sense... self.assertEqual( _pair_members_to_new_node(dm, 'a', 'b', False), (-16, 20)) if __name__ == "__main__": main()