File: test_linalg.py

package info (click to toggle)
python-bayespy 0.6.2-1
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 2,132 kB
  • sloc: python: 22,402; makefile: 156
file content (182 lines) | stat: -rw-r--r-- 6,202 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
################################################################################
# Copyright (C) 2013 Jaakko Luttinen
#
# This file is licensed under the MIT License.
################################################################################


"""
Unit tests for bayespy.utils.linalg module.
"""

import numpy as np

from .. import misc
from .. import linalg

class TestDot(misc.TestCase):

    def test_dot(self):
        """
        Test dot product multiple multi-dimensional arrays.
        """

        # If no arrays, return 0
        self.assertAllClose(linalg.dot(),
                            0)
        # If only one array, return itself
        self.assertAllClose(linalg.dot([[1,2,3],
                                        [4,5,6]]),
                            [[1,2,3],
                             [4,5,6]])
        # Basic test of two arrays: (2,3) * (3,2)
        self.assertAllClose(linalg.dot([[1,2,3],
                                        [4,5,6]],
                                       [[7,8],
                                        [9,1],
                                        [2,3]]),
                            [[31,19],
                             [85,55]])
        # Basic test of four arrays: (2,3) * (3,2) * (2,1) * (1,2)
        self.assertAllClose(linalg.dot([[1,2,3],
                                        [4,5,6]],
                                       [[7,8],
                                        [9,1],
                                        [2,3]],
                                       [[4],
                                        [5]],
                                       [[6,7]]),
                            [[1314,1533],
                             [3690,4305]])

        # Test broadcasting: (2,2,2) * (2,2,2,2)
        self.assertAllClose(linalg.dot([[[1,2],
                                         [3,4]],
                                        [[5,6],
                                         [7,8]]],
                                       [[[[1,2],
                                          [3,4]],
                                         [[5,6],
                                          [7,8]]],
                                        [[[9,1],
                                          [2,3]],
                                         [[4,5],
                                          [6,7]]]]),
                            [[[[  7,  10],
                               [ 15,  22]],

                              [[ 67,  78],
                               [ 91, 106]]],


                             [[[ 13,   7],
                               [ 35,  15]],

                              [[ 56,  67],
                               [ 76,  91]]]])

        # Inconsistent shapes: (2,3) * (2,3)
        self.assertRaises(ValueError,
                          linalg.dot,
                          [[1,2,3],
                           [4,5,6]],
                          [[1,2,3],
                           [4,5,6]])
        # Other axes do not broadcast: (2,2,2) * (3,2,2)
        self.assertRaises(ValueError,
                          linalg.dot,
                          [[[1,2],
                            [3,4]],
                           [[5,6],
                            [7,8]]],
                          [[[1,2],
                            [3,4]],
                           [[5,6],
                            [7,8]],
                           [[9,1],
                            [2,3]]])
        # Do not broadcast matrix axes: (2,1) * (3,2)
        self.assertRaises(ValueError,
                          linalg.dot,
                          [[1],
                           [2]],
                          [[1,2,3],
                           [4,5,6]])
        # Do not accept less than 2-D arrays: (2) * (2,2)
        self.assertRaises(ValueError,
                          linalg.dot,
                          [1,2],
                          [[1,2,3],
                           [4,5,6]])

class TestBandedSolve(misc.TestCase):

    def test_block_banded_solve(self):
        """
        Test the Gaussian elimination algorithm for block-banded matrices.
        """

        #
        # Create a block-banded matrix
        #

        # Number of blocks
        N = 40

        # Random sizes of the blocks
        #D = np.random.randint(5, 10, size=N)
        # Fixed sizes of the blocks
        D = 5*np.ones(N, dtype=np.int64)

        # Some helpful variables to create the covariances
        W = [np.random.randn(D[i], 2*D[i])
             for i in range(N)]

        # The diagonal blocks (covariances)
        A = [np.dot(W[i], W[i].T) for i in range(N)]
        # The superdiagonal blocks (cross-covariances)
        B = [np.dot(W[i][:,-1:], W[i+1][:,:1].T) for i in range(N-1)]

        C = misc.block_banded(A, B)

        # Create the system to be solved: y=C*x
        x_true = np.random.randn(np.sum(D))
        y = np.dot(C, x_true)
        x_true = np.reshape(x_true, (N, -1))
        y = np.reshape(y, (N, -1))

        #
        # Run tests
        #

        # The correct inverse
        invC = np.linalg.inv(C)

        # Inverse from the function that is tested
        (invA, invB, x, ldet) = linalg.block_banded_solve(np.asarray(A),
                                                          np.asarray(B),
                                                          np.asarray(y))

        # Check that you get the correct number of blocks
        self.assertEqual(len(invA), N)
        self.assertEqual(len(invB), N-1)

        # Check each block
        i0 = 0
        for i in range(N-1):
            i1 = i0 + D[i]
            i2 = i1 + D[i+1]
            # Check diagonal block
            self.assertTrue(np.allclose(invA[i], invC[i0:i1, i0:i1]))
            # Check super-diagonal block
            self.assertTrue(np.allclose(invB[i], invC[i0:i1, i1:i2]))
            i0 = i1
        # Check last block
        self.assertTrue(np.allclose(invA[-1], invC[i0:, i0:]))

        # Check the solution of the system
        self.assertTrue(np.allclose(x_true, x))

        # Check the log determinant
        self.assertAlmostEqual(ldet/np.linalg.slogdet(C)[1], 1)