ai-content-maker/.venv/Lib/site-packages/sklearn/linear_model/tests/test_ransac.py

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2024-05-03 04:18:51 +03:00
import numpy as np
import pytest
from numpy.testing import assert_array_almost_equal, assert_array_equal
from sklearn.datasets import make_regression
from sklearn.exceptions import ConvergenceWarning
from sklearn.linear_model import (
LinearRegression,
OrthogonalMatchingPursuit,
RANSACRegressor,
Ridge,
)
from sklearn.linear_model._ransac import _dynamic_max_trials
from sklearn.utils import check_random_state
from sklearn.utils._testing import assert_allclose
from sklearn.utils.fixes import COO_CONTAINERS, CSC_CONTAINERS, CSR_CONTAINERS
# Generate coordinates of line
X = np.arange(-200, 200)
y = 0.2 * X + 20
data = np.column_stack([X, y])
# Add some faulty data
rng = np.random.RandomState(1000)
outliers = np.unique(rng.randint(len(X), size=200))
data[outliers, :] += 50 + rng.rand(len(outliers), 2) * 10
X = data[:, 0][:, np.newaxis]
y = data[:, 1]
def test_ransac_inliers_outliers():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
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_array_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_is_data_valid():
def is_data_valid(X, y):
assert X.shape[0] == 2
assert y.shape[0] == 2
return False
rng = np.random.RandomState(0)
X = rng.rand(10, 2)
y = rng.rand(10, 1)
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
is_data_valid=is_data_valid,
random_state=0,
)
with pytest.raises(ValueError):
ransac_estimator.fit(X, y)
def test_ransac_is_model_valid():
def is_model_valid(estimator, X, y):
assert X.shape[0] == 2
assert y.shape[0] == 2
return False
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
is_model_valid=is_model_valid,
random_state=0,
)
with pytest.raises(ValueError):
ransac_estimator.fit(X, y)
def test_ransac_max_trials():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
max_trials=0,
random_state=0,
)
with pytest.raises(ValueError):
ransac_estimator.fit(X, y)
# there is a 1e-9 chance it will take these many trials. No good reason
# 1e-2 isn't enough, can still happen
# 2 is the what ransac defines as min_samples = X.shape[1] + 1
max_trials = _dynamic_max_trials(len(X) - len(outliers), X.shape[0], 2, 1 - 1e-9)
ransac_estimator = RANSACRegressor(estimator, min_samples=2)
for i in range(50):
ransac_estimator.set_params(min_samples=2, random_state=i)
ransac_estimator.fit(X, y)
assert ransac_estimator.n_trials_ < max_trials + 1
def test_ransac_stop_n_inliers():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
stop_n_inliers=2,
random_state=0,
)
ransac_estimator.fit(X, y)
assert ransac_estimator.n_trials_ == 1
def test_ransac_stop_score():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
stop_score=0,
random_state=0,
)
ransac_estimator.fit(X, y)
assert ransac_estimator.n_trials_ == 1
def test_ransac_score():
X = np.arange(100)[:, None]
y = np.zeros((100,))
y[0] = 1
y[1] = 100
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, min_samples=2, residual_threshold=0.5, random_state=0
)
ransac_estimator.fit(X, y)
assert ransac_estimator.score(X[2:], y[2:]) == 1
assert 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
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, min_samples=2, residual_threshold=0.5, random_state=0
)
ransac_estimator.fit(X, y)
assert_array_equal(ransac_estimator.predict(X), np.zeros(100))
def test_ransac_no_valid_data():
def is_data_valid(X, y):
return False
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, is_data_valid=is_data_valid, max_trials=5
)
msg = "RANSAC could not find a valid consensus set"
with pytest.raises(ValueError, match=msg):
ransac_estimator.fit(X, y)
assert ransac_estimator.n_skips_no_inliers_ == 0
assert ransac_estimator.n_skips_invalid_data_ == 5
assert ransac_estimator.n_skips_invalid_model_ == 0
def test_ransac_no_valid_model():
def is_model_valid(estimator, X, y):
return False
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, is_model_valid=is_model_valid, max_trials=5
)
msg = "RANSAC could not find a valid consensus set"
with pytest.raises(ValueError, match=msg):
ransac_estimator.fit(X, y)
assert ransac_estimator.n_skips_no_inliers_ == 0
assert ransac_estimator.n_skips_invalid_data_ == 0
assert ransac_estimator.n_skips_invalid_model_ == 5
def test_ransac_exceed_max_skips():
def is_data_valid(X, y):
return False
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, is_data_valid=is_data_valid, max_trials=5, max_skips=3
)
msg = "RANSAC skipped more iterations than `max_skips`"
with pytest.raises(ValueError, match=msg):
ransac_estimator.fit(X, y)
assert ransac_estimator.n_skips_no_inliers_ == 0
assert ransac_estimator.n_skips_invalid_data_ == 4
assert ransac_estimator.n_skips_invalid_model_ == 0
def test_ransac_warn_exceed_max_skips():
global cause_skip
cause_skip = False
def is_data_valid(X, y):
global cause_skip
if not cause_skip:
cause_skip = True
return True
else:
return False
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, is_data_valid=is_data_valid, max_skips=3, max_trials=5
)
warning_message = (
"RANSAC found a valid consensus set but exited "
"early due to skipping more iterations than "
"`max_skips`. See estimator attributes for "
"diagnostics."
)
with pytest.warns(ConvergenceWarning, match=warning_message):
ransac_estimator.fit(X, y)
assert ransac_estimator.n_skips_no_inliers_ == 0
assert ransac_estimator.n_skips_invalid_data_ == 4
assert ransac_estimator.n_skips_invalid_model_ == 0
@pytest.mark.parametrize(
"sparse_container", COO_CONTAINERS + CSR_CONTAINERS + CSC_CONTAINERS
)
def test_ransac_sparse(sparse_container):
X_sparse = sparse_container(X)
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
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_array_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_none_estimator():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
estimator, min_samples=2, residual_threshold=5, random_state=0
)
ransac_none_estimator = RANSACRegressor(
None, min_samples=2, residual_threshold=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():
estimator = LinearRegression()
ransac_estimator1 = RANSACRegressor(
estimator, min_samples=2, residual_threshold=5, random_state=0
)
ransac_estimator2 = RANSACRegressor(
estimator,
min_samples=2.0 / X.shape[0],
residual_threshold=5,
random_state=0,
)
ransac_estimator5 = RANSACRegressor(
estimator, min_samples=2, residual_threshold=5, random_state=0
)
ransac_estimator6 = RANSACRegressor(estimator, residual_threshold=5, random_state=0)
ransac_estimator7 = RANSACRegressor(
estimator, min_samples=X.shape[0] + 1, residual_threshold=5, random_state=0
)
# GH #19390
ransac_estimator8 = RANSACRegressor(
Ridge(), min_samples=None, 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)
)
with pytest.raises(ValueError):
ransac_estimator7.fit(X, y)
err_msg = "`min_samples` needs to be explicitly set"
with pytest.raises(ValueError, match=err_msg):
ransac_estimator8.fit(X, y)
def test_ransac_multi_dimensional_targets():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(
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_array_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
def test_ransac_residual_loss():
def loss_multi1(y_true, y_pred):
return np.sum(np.abs(y_true - y_pred), axis=1)
def loss_multi2(y_true, y_pred):
return np.sum((y_true - y_pred) ** 2, axis=1)
def loss_mono(y_true, y_pred):
return np.abs(y_true - y_pred)
yyy = np.column_stack([y, y, y])
estimator = LinearRegression()
ransac_estimator0 = RANSACRegressor(
estimator, min_samples=2, residual_threshold=5, random_state=0
)
ransac_estimator1 = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
random_state=0,
loss=loss_multi1,
)
ransac_estimator2 = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
random_state=0,
loss=loss_multi2,
)
# 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.loss = loss_mono
ransac_estimator2.fit(X, y)
assert_array_almost_equal(
ransac_estimator0.predict(X), ransac_estimator2.predict(X)
)
ransac_estimator3 = RANSACRegressor(
estimator,
min_samples=2,
residual_threshold=5,
random_state=0,
loss="squared_error",
)
ransac_estimator3.fit(X, y)
assert_array_almost_equal(
ransac_estimator0.predict(X), ransac_estimator2.predict(X)
)
def test_ransac_default_residual_threshold():
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(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_array_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 _dynamic_max_trials(100, 100, 2, 0.99) == 1
# e = 5%, min_samples = 2
assert _dynamic_max_trials(95, 100, 2, 0.99) == 2
# e = 10%, min_samples = 2
assert _dynamic_max_trials(90, 100, 2, 0.99) == 3
# e = 30%, min_samples = 2
assert _dynamic_max_trials(70, 100, 2, 0.99) == 7
# e = 50%, min_samples = 2
assert _dynamic_max_trials(50, 100, 2, 0.99) == 17
# e = 5%, min_samples = 8
assert _dynamic_max_trials(95, 100, 8, 0.99) == 5
# e = 10%, min_samples = 8
assert _dynamic_max_trials(90, 100, 8, 0.99) == 9
# e = 30%, min_samples = 8
assert _dynamic_max_trials(70, 100, 8, 0.99) == 78
# e = 50%, min_samples = 8
assert _dynamic_max_trials(50, 100, 8, 0.99) == 1177
# e = 0%, min_samples = 10
assert _dynamic_max_trials(1, 100, 10, 0) == 0
assert _dynamic_max_trials(1, 100, 10, 1) == float("inf")
def test_ransac_fit_sample_weight():
ransac_estimator = RANSACRegressor(random_state=0)
n_samples = y.shape[0]
weights = np.ones(n_samples)
ransac_estimator.fit(X, y, weights)
# sanity check
assert ransac_estimator.inlier_mask_.shape[0] == n_samples
ref_inlier_mask = np.ones_like(ransac_estimator.inlier_mask_).astype(np.bool_)
ref_inlier_mask[outliers] = False
# check that mask is correct
assert_array_equal(ransac_estimator.inlier_mask_, ref_inlier_mask)
# check that fit(X) = fit([X1, X2, X3],sample_weight = [n1, n2, n3]) where
# X = X1 repeated n1 times, X2 repeated n2 times and so forth
random_state = check_random_state(0)
X_ = random_state.randint(0, 200, [10, 1])
y_ = np.ndarray.flatten(0.2 * X_ + 2)
sample_weight = random_state.randint(0, 10, 10)
outlier_X = random_state.randint(0, 1000, [1, 1])
outlier_weight = random_state.randint(0, 10, 1)
outlier_y = random_state.randint(-1000, 0, 1)
X_flat = np.append(
np.repeat(X_, sample_weight, axis=0),
np.repeat(outlier_X, outlier_weight, axis=0),
axis=0,
)
y_flat = np.ndarray.flatten(
np.append(
np.repeat(y_, sample_weight, axis=0),
np.repeat(outlier_y, outlier_weight, axis=0),
axis=0,
)
)
ransac_estimator.fit(X_flat, y_flat)
ref_coef_ = ransac_estimator.estimator_.coef_
sample_weight = np.append(sample_weight, outlier_weight)
X_ = np.append(X_, outlier_X, axis=0)
y_ = np.append(y_, outlier_y)
ransac_estimator.fit(X_, y_, sample_weight)
assert_allclose(ransac_estimator.estimator_.coef_, ref_coef_)
# check that if estimator.fit doesn't support
# sample_weight, raises error
estimator = OrthogonalMatchingPursuit()
ransac_estimator = RANSACRegressor(estimator, min_samples=10)
err_msg = f"{estimator.__class__.__name__} does not support sample_weight."
with pytest.raises(ValueError, match=err_msg):
ransac_estimator.fit(X, y, weights)
def test_ransac_final_model_fit_sample_weight():
X, y = make_regression(n_samples=1000, random_state=10)
rng = check_random_state(42)
sample_weight = rng.randint(1, 4, size=y.shape[0])
sample_weight = sample_weight / sample_weight.sum()
ransac = RANSACRegressor(estimator=LinearRegression(), random_state=0)
ransac.fit(X, y, sample_weight=sample_weight)
final_model = LinearRegression()
mask_samples = ransac.inlier_mask_
final_model.fit(
X[mask_samples], y[mask_samples], sample_weight=sample_weight[mask_samples]
)
assert_allclose(ransac.estimator_.coef_, final_model.coef_, atol=1e-12)
def test_perfect_horizontal_line():
"""Check that we can fit a line where all samples are inliers.
Non-regression test for:
https://github.com/scikit-learn/scikit-learn/issues/19497
"""
X = np.arange(100)[:, None]
y = np.zeros((100,))
estimator = LinearRegression()
ransac_estimator = RANSACRegressor(estimator, random_state=0)
ransac_estimator.fit(X, y)
assert_allclose(ransac_estimator.estimator_.coef_, 0.0)
assert_allclose(ransac_estimator.estimator_.intercept_, 0.0)