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
|
import numpy as np
import pytest
from scipy import sparse as sp
from numpy.testing import assert_array_equal
from sklearn.base import BaseEstimator
from sklearn.feature_selection._base import SelectorMixin
from sklearn.utils import check_array
class StepSelector(SelectorMixin, BaseEstimator):
"""Retain every `step` features (beginning with 0)"""
def __init__(self, step=2):
self.step = step
def fit(self, X, y=None):
X = check_array(X, accept_sparse="csc")
self.n_input_feats = X.shape[1]
return self
def _get_support_mask(self):
mask = np.zeros(self.n_input_feats, dtype=bool)
mask[:: self.step] = True
return mask
support = [True, False] * 5
support_inds = [0, 2, 4, 6, 8]
X = np.arange(20).reshape(2, 10)
Xt = np.arange(0, 20, 2).reshape(2, 5)
Xinv = X.copy()
Xinv[:, 1::2] = 0
y = [0, 1]
feature_names = list("ABCDEFGHIJ")
feature_names_t = feature_names[::2]
feature_names_inv = np.array(feature_names)
feature_names_inv[1::2] = ""
def test_transform_dense():
sel = StepSelector()
Xt_actual = sel.fit(X, y).transform(X)
Xt_actual2 = StepSelector().fit_transform(X, y)
assert_array_equal(Xt, Xt_actual)
assert_array_equal(Xt, Xt_actual2)
# Check dtype matches
assert np.int32 == sel.transform(X.astype(np.int32)).dtype
assert np.float32 == sel.transform(X.astype(np.float32)).dtype
# Check 1d list and other dtype:
names_t_actual = sel.transform([feature_names])
assert_array_equal(feature_names_t, names_t_actual.ravel())
# Check wrong shape raises error
with pytest.raises(ValueError):
sel.transform(np.array([[1], [2]]))
def test_transform_sparse():
sparse = sp.csc_matrix
sel = StepSelector()
Xt_actual = sel.fit(sparse(X)).transform(sparse(X))
Xt_actual2 = sel.fit_transform(sparse(X))
assert_array_equal(Xt, Xt_actual.toarray())
assert_array_equal(Xt, Xt_actual2.toarray())
# Check dtype matches
assert np.int32 == sel.transform(sparse(X).astype(np.int32)).dtype
assert np.float32 == sel.transform(sparse(X).astype(np.float32)).dtype
# Check wrong shape raises error
with pytest.raises(ValueError):
sel.transform(np.array([[1], [2]]))
def test_inverse_transform_dense():
sel = StepSelector()
Xinv_actual = sel.fit(X, y).inverse_transform(Xt)
assert_array_equal(Xinv, Xinv_actual)
# Check dtype matches
assert np.int32 == sel.inverse_transform(Xt.astype(np.int32)).dtype
assert np.float32 == sel.inverse_transform(Xt.astype(np.float32)).dtype
# Check 1d list and other dtype:
names_inv_actual = sel.inverse_transform([feature_names_t])
assert_array_equal(feature_names_inv, names_inv_actual.ravel())
# Check wrong shape raises error
with pytest.raises(ValueError):
sel.inverse_transform(np.array([[1], [2]]))
def test_inverse_transform_sparse():
sparse = sp.csc_matrix
sel = StepSelector()
Xinv_actual = sel.fit(sparse(X)).inverse_transform(sparse(Xt))
assert_array_equal(Xinv, Xinv_actual.toarray())
# Check dtype matches
assert np.int32 == sel.inverse_transform(sparse(Xt).astype(np.int32)).dtype
assert np.float32 == sel.inverse_transform(sparse(Xt).astype(np.float32)).dtype
# Check wrong shape raises error
with pytest.raises(ValueError):
sel.inverse_transform(np.array([[1], [2]]))
def test_get_support():
sel = StepSelector()
sel.fit(X, y)
assert_array_equal(support, sel.get_support())
assert_array_equal(support_inds, sel.get_support(indices=True))
|
