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steminc
steminc / scikit-learn python
Repository URL to install this package:
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Version:
0.15.2 ▾
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import numpy as np
from numpy.testing import assert_equal, assert_raises
from numpy.testing import assert_array_almost_equal
from scipy import sparse
from sklearn.utils.testing import assert_less
from sklearn.linear_model import LinearRegression, RANSACRegressor
from sklearn.linear_model.ransac import _dynamic_max_trials
# Generate coordinates of line
X = np.arange(-200, 200)
y = 0.2 * X + 20
data = np.column_stack([X, y])
# Add some faulty data
outliers = np.array((10, 30, 200))
data[outliers[0], :] = (1000, 1000)
data[outliers[1], :] = (-1000, -1000)
data[outliers[2], :] = (-100, -50)
X = data[:, 0][:, np.newaxis]
y = data[:, 1]
def test_ransac_inliers_outliers():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
# Estimate parameters of corrupted data
ransac_estimator.fit(X, y)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_is_data_valid():
def is_data_valid(X, y):
assert_equal(X.shape[0], 2)
assert_equal(y.shape[0], 2)
return False
X = np.random.rand(10, 2)
y = np.random.rand(10, 1)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5,
is_data_valid=is_data_valid,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
def test_ransac_is_model_valid():
def is_model_valid(estimator, X, y):
assert_equal(X.shape[0], 2)
assert_equal(y.shape[0], 2)
return False
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5,
is_model_valid=is_model_valid,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
def test_ransac_max_trials():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, max_trials=0,
random_state=0)
assert_raises(ValueError, ransac_estimator.fit, X, y)
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, max_trials=11,
random_state=0)
assert getattr(ransac_estimator, 'n_trials_', None) is None
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.n_trials_, 2)
def test_ransac_stop_n_inliers():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, stop_n_inliers=2,
random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.n_trials_, 1)
def test_ransac_stop_score():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, stop_score=0,
random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.n_trials_, 1)
def test_ransac_score():
X = np.arange(100)[:, None]
y = np.zeros((100, ))
y[0] = 1
y[1] = 100
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=0.5, random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.score(X[2:], y[2:]), 1)
assert_less(ransac_estimator.score(X[:2], y[:2]), 1)
def test_ransac_predict():
X = np.arange(100)[:, None]
y = np.zeros((100, ))
y[0] = 1
y[1] = 100
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=0.5, random_state=0)
ransac_estimator.fit(X, y)
assert_equal(ransac_estimator.predict(X), np.zeros((100, 1)))
def test_ransac_sparse_coo():
X_sparse = sparse.coo_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_sparse_csr():
X_sparse = sparse.csr_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_sparse_csc():
X_sparse = sparse.csc_matrix(X)
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator.fit(X_sparse, y)
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_none_estimator():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_none_estimator = RANSACRegressor(None, 2, 5, random_state=0)
ransac_estimator.fit(X, y)
ransac_none_estimator.fit(X, y)
assert_array_almost_equal(ransac_estimator.predict(X),
ransac_none_estimator.predict(X))
def test_ransac_min_n_samples():
base_estimator = LinearRegression()
ransac_estimator1 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator2 = RANSACRegressor(base_estimator,
min_samples=2. / X.shape[0],
residual_threshold=5, random_state=0)
ransac_estimator3 = RANSACRegressor(base_estimator, min_samples=-1,
residual_threshold=5, random_state=0)
ransac_estimator4 = RANSACRegressor(base_estimator, min_samples=5.2,
residual_threshold=5, random_state=0)
ransac_estimator5 = RANSACRegressor(base_estimator, min_samples=2.0,
residual_threshold=5, random_state=0)
ransac_estimator6 = RANSACRegressor(base_estimator,
residual_threshold=5, random_state=0)
ransac_estimator7 = RANSACRegressor(base_estimator,
min_samples=X.shape[0] + 1,
residual_threshold=5, random_state=0)
ransac_estimator1.fit(X, y)
ransac_estimator2.fit(X, y)
ransac_estimator5.fit(X, y)
ransac_estimator6.fit(X, y)
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator2.predict(X))
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator5.predict(X))
assert_array_almost_equal(ransac_estimator1.predict(X),
ransac_estimator6.predict(X))
assert_raises(ValueError, ransac_estimator3.fit, X, y)
assert_raises(ValueError, ransac_estimator4.fit, X, y)
assert_raises(ValueError, ransac_estimator7.fit, X, y)
def test_ransac_multi_dimensional_targets():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
# 3-D target values
yyy = np.column_stack([y, y, y])
# Estimate parameters of corrupted data
ransac_estimator.fit(X, yyy)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_residual_metric():
residual_metric1 = lambda dy: np.sum(np.abs(dy), axis=1)
residual_metric2 = lambda dy: np.sum(dy ** 2, axis=1)
yyy = np.column_stack([y, y, y])
base_estimator = LinearRegression()
ransac_estimator0 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0)
ransac_estimator1 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
residual_metric=residual_metric1)
ransac_estimator2 = RANSACRegressor(base_estimator, min_samples=2,
residual_threshold=5, random_state=0,
residual_metric=residual_metric2)
# multi-dimensional
ransac_estimator0.fit(X, yyy)
ransac_estimator1.fit(X, yyy)
ransac_estimator2.fit(X, yyy)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator1.predict(X))
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
# one-dimensional
ransac_estimator0.fit(X, y)
ransac_estimator2.fit(X, y)
assert_array_almost_equal(ransac_estimator0.predict(X),
ransac_estimator2.predict(X))
def test_ransac_default_residual_threshold():
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
random_state=0)
# Estimate parameters of corrupted data
ransac_estimator.fit(X, y)
# Ground truth / reference inlier mask
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_
).astype(np.bool_)
ref_inlier_mask[outliers] = False
assert_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_dynamic_max_trials():
# Numbers hand-calculated and confirmed on page 119 (Table 4.3) in
# Hartley, R.~I. and Zisserman, A., 2004,
# Multiple View Geometry in Computer Vision, Second Edition,
# Cambridge University Press, ISBN: 0521540518
# e = 0%, min_samples = X
assert_equal(_dynamic_max_trials(100, 100, 2, 0.99), 1)
# e = 5%, min_samples = 2
assert_equal(_dynamic_max_trials(95, 100, 2, 0.99), 2)
# e = 10%, min_samples = 2
assert_equal(_dynamic_max_trials(90, 100, 2, 0.99), 3)
# e = 30%, min_samples = 2
assert_equal(_dynamic_max_trials(70, 100, 2, 0.99), 7)
# e = 50%, min_samples = 2
assert_equal(_dynamic_max_trials(50, 100, 2, 0.99), 17)
# e = 5%, min_samples = 8
assert_equal(_dynamic_max_trials(95, 100, 8, 0.99), 5)
# e = 10%, min_samples = 8
assert_equal(_dynamic_max_trials(90, 100, 8, 0.99), 9)
# e = 30%, min_samples = 8
assert_equal(_dynamic_max_trials(70, 100, 8, 0.99), 78)
# e = 50%, min_samples = 8
assert_equal(_dynamic_max_trials(50, 100, 8, 0.99), 1177)
# e = 0%, min_samples = 10
assert_equal(_dynamic_max_trials(1, 100, 10, 0), 0)
assert_equal(_dynamic_max_trials(1, 100, 10, 1), float('inf'))
base_estimator = LinearRegression()
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
stop_probability=-0.1)
assert_raises(ValueError, ransac_estimator.fit, X, y)
ransac_estimator = RANSACRegressor(base_estimator, min_samples=2,
stop_probability=1.1)
assert_raises(ValueError, ransac_estimator.fit, X, y)
if __name__ == "__main__":
np.testing.run_module_suite()