summaryrefslogtreecommitdiff
path: root/numpy/lib/tests/test_index_tricks.py
blob: c17ee5d6a2d92be5d54c6b79a7997d0e82a7ce50 (plain)
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
from numpy.testing import *
import numpy as np
from numpy import ( array, ones, r_, mgrid, unravel_index, zeros, where,
                    ndenumerate, fill_diagonal, diag_indices,
                    diag_indices_from, s_, index_exp )

class TestUnravelIndex(TestCase):
    def test_basic(self):
        assert unravel_index(2,(2,2)) == (1,0)
        assert unravel_index(254,(17,94)) == (2, 66)
        assert_raises(ValueError, unravel_index, 4,(2,2))


class TestGrid(TestCase):
    def test_basic(self):
        a = mgrid[-1:1:10j]
        b = mgrid[-1:1:0.1]
        assert(a.shape == (10,))
        assert(b.shape == (20,))
        assert(a[0] == -1)
        assert_almost_equal(a[-1],1)
        assert(b[0] == -1)
        assert_almost_equal(b[1]-b[0],0.1,11)
        assert_almost_equal(b[-1],b[0]+19*0.1,11)
        assert_almost_equal(a[1]-a[0],2.0/9.0,11)

    def test_linspace_equivalence(self):
        y,st = np.linspace(2,10,retstep=1)
        assert_almost_equal(st,8/49.0)
        assert_array_almost_equal(y,mgrid[2:10:50j],13)

    def test_nd(self):
        c = mgrid[-1:1:10j,-2:2:10j]
        d = mgrid[-1:1:0.1,-2:2:0.2]
        assert(c.shape == (2,10,10))
        assert(d.shape == (2,20,20))
        assert_array_equal(c[0][0,:],-ones(10,'d'))
        assert_array_equal(c[1][:,0],-2*ones(10,'d'))
        assert_array_almost_equal(c[0][-1,:],ones(10,'d'),11)
        assert_array_almost_equal(c[1][:,-1],2*ones(10,'d'),11)
        assert_array_almost_equal(d[0,1,:]-d[0,0,:], 0.1*ones(20,'d'),11)
        assert_array_almost_equal(d[1,:,1]-d[1,:,0], 0.2*ones(20,'d'),11)


class TestConcatenator(TestCase):
    def test_1d(self):
        assert_array_equal(r_[1,2,3,4,5,6],array([1,2,3,4,5,6]))
        b = ones(5)
        c = r_[b,0,0,b]
        assert_array_equal(c,[1,1,1,1,1,0,0,1,1,1,1,1])

    def test_mixed_type(self):
        g = r_[10.1, 1:10]
        assert(g.dtype == 'f8')

    def test_more_mixed_type(self):
        g = r_[-10.1, array([1]), array([2,3,4]), 10.0]
        assert(g.dtype == 'f8')

    def test_2d(self):
        b = rand(5,5)
        c = rand(5,5)
        d = r_['1',b,c]  # append columns
        assert(d.shape == (5,10))
        assert_array_equal(d[:,:5],b)
        assert_array_equal(d[:,5:],c)
        d = r_[b,c]
        assert(d.shape == (10,5))
        assert_array_equal(d[:5,:],b)
        assert_array_equal(d[5:,:],c)


class TestNdenumerate(TestCase):
    def test_basic(self):
        a = array([[1,2], [3,4]])
        assert_equal(list(ndenumerate(a)),
                     [((0,0), 1), ((0,1), 2), ((1,0), 3), ((1,1), 4)])


class TestIndexExpression(TestCase):
    def test_regression_1(self):
        # ticket #1196
        a = np.arange(2)
        assert_equal(a[:-1], a[s_[:-1]])
        assert_equal(a[:-1], a[index_exp[:-1]])

    def test_simple_1(self):
        a = np.random.rand(4,5,6)

        assert_equal(a[:,:3,[1,2]], a[index_exp[:,:3,[1,2]]])
        assert_equal(a[:,:3,[1,2]], a[s_[:,:3,[1,2]]])

def test_fill_diagonal():
    a = zeros((3, 3),int)
    fill_diagonal(a, 5)
    yield (assert_array_equal, a,
           array([[5, 0, 0],
                  [0, 5, 0],
                  [0, 0, 5]]))

    # The same function can operate on a 4-d array:
    a = zeros((3, 3, 3, 3), int)
    fill_diagonal(a, 4)
    i = array([0, 1, 2])
    yield (assert_equal, where(a != 0), (i, i, i, i))


def test_diag_indices():
    di = diag_indices(4)
    a = array([[1, 2, 3, 4],
               [5, 6, 7, 8],
               [9, 10, 11, 12],
               [13, 14, 15, 16]])
    a[di] = 100
    yield (assert_array_equal, a,
           array([[100,   2,   3,   4],
                  [  5, 100,   7,   8],
                  [  9,  10, 100,  12],
                  [ 13,  14,  15, 100]]))

    # Now, we create indices to manipulate a 3-d array:
    d3 = diag_indices(2, 3)

    # And use it to set the diagonal of a zeros array to 1:
    a = zeros((2, 2, 2),int)
    a[d3] = 1
    yield (assert_array_equal, a,
           array([[[1, 0],
                   [0, 0]],

                  [[0, 0],
                   [0, 1]]]) )

def test_diag_indices_from():
    x = np.random.random((4, 4))
    r, c = diag_indices_from(x)
    assert_array_equal(r, np.arange(4))
    assert_array_equal(c, np.arange(4))


if __name__ == "__main__":
    run_module_suite()