2171 lines
68 KiB
Python
2171 lines
68 KiB
Python
import pickle
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import joblib
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import pytest
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import numpy as np
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import scipy.sparse as sp
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from unittest.mock import Mock
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from sklearn.utils._testing import assert_allclose
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from sklearn.utils._testing import assert_array_equal
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from sklearn.utils._testing import assert_almost_equal
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from sklearn.utils._testing import assert_array_almost_equal
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from sklearn.utils._testing import ignore_warnings
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from sklearn import linear_model, datasets, metrics
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from sklearn.base import clone, is_classifier
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from sklearn.svm import OneClassSVM
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from sklearn.preprocessing import LabelEncoder, scale, MinMaxScaler
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from sklearn.preprocessing import StandardScaler
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from sklearn.kernel_approximation import Nystroem
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from sklearn.pipeline import make_pipeline
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from sklearn.exceptions import ConvergenceWarning
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from sklearn.model_selection import StratifiedShuffleSplit, ShuffleSplit
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from sklearn.linear_model import _sgd_fast as sgd_fast
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from sklearn.linear_model import _stochastic_gradient
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from sklearn.model_selection import RandomizedSearchCV
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def _update_kwargs(kwargs):
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if "random_state" not in kwargs:
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kwargs["random_state"] = 42
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if "tol" not in kwargs:
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kwargs["tol"] = None
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if "max_iter" not in kwargs:
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kwargs["max_iter"] = 5
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class _SparseSGDClassifier(linear_model.SGDClassifier):
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def fit(self, X, y, *args, **kw):
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X = sp.csr_matrix(X)
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return super().fit(X, y, *args, **kw)
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def partial_fit(self, X, y, *args, **kw):
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X = sp.csr_matrix(X)
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return super().partial_fit(X, y, *args, **kw)
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def decision_function(self, X):
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X = sp.csr_matrix(X)
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return super().decision_function(X)
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def predict_proba(self, X):
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X = sp.csr_matrix(X)
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return super().predict_proba(X)
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class _SparseSGDRegressor(linear_model.SGDRegressor):
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def fit(self, X, y, *args, **kw):
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X = sp.csr_matrix(X)
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return linear_model.SGDRegressor.fit(self, X, y, *args, **kw)
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def partial_fit(self, X, y, *args, **kw):
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X = sp.csr_matrix(X)
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return linear_model.SGDRegressor.partial_fit(self, X, y, *args, **kw)
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def decision_function(self, X, *args, **kw):
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# XXX untested as of v0.22
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X = sp.csr_matrix(X)
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return linear_model.SGDRegressor.decision_function(self, X, *args, **kw)
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class _SparseSGDOneClassSVM(linear_model.SGDOneClassSVM):
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def fit(self, X, *args, **kw):
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X = sp.csr_matrix(X)
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return linear_model.SGDOneClassSVM.fit(self, X, *args, **kw)
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def partial_fit(self, X, *args, **kw):
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X = sp.csr_matrix(X)
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return linear_model.SGDOneClassSVM.partial_fit(self, X, *args, **kw)
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def decision_function(self, X, *args, **kw):
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X = sp.csr_matrix(X)
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return linear_model.SGDOneClassSVM.decision_function(self, X, *args, **kw)
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def SGDClassifier(**kwargs):
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_update_kwargs(kwargs)
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return linear_model.SGDClassifier(**kwargs)
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def SGDRegressor(**kwargs):
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_update_kwargs(kwargs)
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return linear_model.SGDRegressor(**kwargs)
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def SGDOneClassSVM(**kwargs):
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_update_kwargs(kwargs)
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return linear_model.SGDOneClassSVM(**kwargs)
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def SparseSGDClassifier(**kwargs):
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_update_kwargs(kwargs)
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return _SparseSGDClassifier(**kwargs)
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def SparseSGDRegressor(**kwargs):
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_update_kwargs(kwargs)
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return _SparseSGDRegressor(**kwargs)
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def SparseSGDOneClassSVM(**kwargs):
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_update_kwargs(kwargs)
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return _SparseSGDOneClassSVM(**kwargs)
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# Test Data
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# test sample 1
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X = np.array([[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]])
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Y = [1, 1, 1, 2, 2, 2]
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T = np.array([[-1, -1], [2, 2], [3, 2]])
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true_result = [1, 2, 2]
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# test sample 2; string class labels
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X2 = np.array(
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[
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[-1, 1],
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[-0.75, 0.5],
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[-1.5, 1.5],
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[1, 1],
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[0.75, 0.5],
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[1.5, 1.5],
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[-1, -1],
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[0, -0.5],
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[1, -1],
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]
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)
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Y2 = ["one"] * 3 + ["two"] * 3 + ["three"] * 3
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T2 = np.array([[-1.5, 0.5], [1, 2], [0, -2]])
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true_result2 = ["one", "two", "three"]
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# test sample 3
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X3 = np.array(
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[
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[1, 1, 0, 0, 0, 0],
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[1, 1, 0, 0, 0, 0],
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[0, 0, 1, 0, 0, 0],
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[0, 0, 1, 0, 0, 0],
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[0, 0, 0, 0, 1, 1],
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[0, 0, 0, 0, 1, 1],
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[0, 0, 0, 1, 0, 0],
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[0, 0, 0, 1, 0, 0],
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]
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)
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Y3 = np.array([1, 1, 1, 1, 2, 2, 2, 2])
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# test sample 4 - two more or less redundant feature groups
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X4 = np.array(
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[
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[1, 0.9, 0.8, 0, 0, 0],
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[1, 0.84, 0.98, 0, 0, 0],
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[1, 0.96, 0.88, 0, 0, 0],
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[1, 0.91, 0.99, 0, 0, 0],
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[0, 0, 0, 0.89, 0.91, 1],
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[0, 0, 0, 0.79, 0.84, 1],
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[0, 0, 0, 0.91, 0.95, 1],
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[0, 0, 0, 0.93, 1, 1],
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]
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)
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Y4 = np.array([1, 1, 1, 1, 2, 2, 2, 2])
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iris = datasets.load_iris()
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# test sample 5 - test sample 1 as binary classification problem
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X5 = np.array([[-2, -1], [-1, -1], [-1, -2], [1, 1], [1, 2], [2, 1]])
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Y5 = [1, 1, 1, 2, 2, 2]
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true_result5 = [0, 1, 1]
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###############################################################################
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# Common Test Case to classification and regression
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# a simple implementation of ASGD to use for testing
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# uses squared loss to find the gradient
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def asgd(klass, X, y, eta, alpha, weight_init=None, intercept_init=0.0):
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if weight_init is None:
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weights = np.zeros(X.shape[1])
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else:
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weights = weight_init
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average_weights = np.zeros(X.shape[1])
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intercept = intercept_init
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average_intercept = 0.0
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decay = 1.0
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# sparse data has a fixed decay of .01
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if klass in (SparseSGDClassifier, SparseSGDRegressor):
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decay = 0.01
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for i, entry in enumerate(X):
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p = np.dot(entry, weights)
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p += intercept
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gradient = p - y[i]
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weights *= 1.0 - (eta * alpha)
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weights += -(eta * gradient * entry)
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intercept += -(eta * gradient) * decay
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average_weights *= i
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average_weights += weights
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average_weights /= i + 1.0
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average_intercept *= i
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average_intercept += intercept
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average_intercept /= i + 1.0
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return average_weights, average_intercept
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def _test_warm_start(klass, X, Y, lr):
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# Test that explicit warm restart...
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clf = klass(alpha=0.01, eta0=0.01, shuffle=False, learning_rate=lr)
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clf.fit(X, Y)
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clf2 = klass(alpha=0.001, eta0=0.01, shuffle=False, learning_rate=lr)
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clf2.fit(X, Y, coef_init=clf.coef_.copy(), intercept_init=clf.intercept_.copy())
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# ... and implicit warm restart are equivalent.
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clf3 = klass(
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alpha=0.01, eta0=0.01, shuffle=False, warm_start=True, learning_rate=lr
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)
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clf3.fit(X, Y)
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assert clf3.t_ == clf.t_
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assert_array_almost_equal(clf3.coef_, clf.coef_)
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clf3.set_params(alpha=0.001)
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clf3.fit(X, Y)
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assert clf3.t_ == clf2.t_
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assert_array_almost_equal(clf3.coef_, clf2.coef_)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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@pytest.mark.parametrize("lr", ["constant", "optimal", "invscaling", "adaptive"])
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def test_warm_start(klass, lr):
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_test_warm_start(klass, X, Y, lr)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_input_format(klass):
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# Input format tests.
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clf = klass(alpha=0.01, shuffle=False)
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clf.fit(X, Y)
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Y_ = np.array(Y)[:, np.newaxis]
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Y_ = np.c_[Y_, Y_]
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with pytest.raises(ValueError):
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clf.fit(X, Y_)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_clone(klass):
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# Test whether clone works ok.
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clf = klass(alpha=0.01, penalty="l1")
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clf = clone(clf)
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clf.set_params(penalty="l2")
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clf.fit(X, Y)
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clf2 = klass(alpha=0.01, penalty="l2")
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clf2.fit(X, Y)
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assert_array_equal(clf.coef_, clf2.coef_)
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@pytest.mark.parametrize(
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"klass",
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[
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SGDClassifier,
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SparseSGDClassifier,
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SGDRegressor,
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SparseSGDRegressor,
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SGDOneClassSVM,
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SparseSGDOneClassSVM,
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],
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)
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def test_plain_has_no_average_attr(klass):
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clf = klass(average=True, eta0=0.01)
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clf.fit(X, Y)
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assert hasattr(clf, "_average_coef")
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assert hasattr(clf, "_average_intercept")
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assert hasattr(clf, "_standard_intercept")
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assert hasattr(clf, "_standard_coef")
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clf = klass()
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clf.fit(X, Y)
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assert not hasattr(clf, "_average_coef")
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assert not hasattr(clf, "_average_intercept")
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assert not hasattr(clf, "_standard_intercept")
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assert not hasattr(clf, "_standard_coef")
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@pytest.mark.parametrize(
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"klass",
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[
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SGDClassifier,
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SparseSGDClassifier,
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SGDRegressor,
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SparseSGDRegressor,
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SGDOneClassSVM,
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SparseSGDOneClassSVM,
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],
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)
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def test_late_onset_averaging_not_reached(klass):
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clf1 = klass(average=600)
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clf2 = klass()
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for _ in range(100):
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if is_classifier(clf1):
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clf1.partial_fit(X, Y, classes=np.unique(Y))
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clf2.partial_fit(X, Y, classes=np.unique(Y))
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else:
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clf1.partial_fit(X, Y)
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clf2.partial_fit(X, Y)
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assert_array_almost_equal(clf1.coef_, clf2.coef_, decimal=16)
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if klass in [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]:
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assert_almost_equal(clf1.intercept_, clf2.intercept_, decimal=16)
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elif klass in [SGDOneClassSVM, SparseSGDOneClassSVM]:
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assert_allclose(clf1.offset_, clf2.offset_)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_late_onset_averaging_reached(klass):
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eta0 = 0.001
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alpha = 0.0001
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Y_encode = np.array(Y)
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Y_encode[Y_encode == 1] = -1.0
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Y_encode[Y_encode == 2] = 1.0
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clf1 = klass(
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average=7,
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learning_rate="constant",
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loss="squared_error",
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eta0=eta0,
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alpha=alpha,
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max_iter=2,
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shuffle=False,
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)
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clf2 = klass(
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average=0,
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learning_rate="constant",
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loss="squared_error",
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eta0=eta0,
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alpha=alpha,
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max_iter=1,
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shuffle=False,
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)
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clf1.fit(X, Y_encode)
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clf2.fit(X, Y_encode)
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average_weights, average_intercept = asgd(
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klass,
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X,
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Y_encode,
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eta0,
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alpha,
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weight_init=clf2.coef_.ravel(),
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intercept_init=clf2.intercept_,
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)
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assert_array_almost_equal(clf1.coef_.ravel(), average_weights.ravel(), decimal=16)
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assert_almost_equal(clf1.intercept_, average_intercept, decimal=16)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_early_stopping(klass):
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X = iris.data[iris.target > 0]
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Y = iris.target[iris.target > 0]
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for early_stopping in [True, False]:
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max_iter = 1000
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clf = klass(early_stopping=early_stopping, tol=1e-3, max_iter=max_iter).fit(
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X, Y
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)
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assert clf.n_iter_ < max_iter
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_adaptive_longer_than_constant(klass):
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clf1 = klass(learning_rate="adaptive", eta0=0.01, tol=1e-3, max_iter=100)
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clf1.fit(iris.data, iris.target)
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clf2 = klass(learning_rate="constant", eta0=0.01, tol=1e-3, max_iter=100)
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clf2.fit(iris.data, iris.target)
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assert clf1.n_iter_ > clf2.n_iter_
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_validation_set_not_used_for_training(klass):
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X, Y = iris.data, iris.target
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validation_fraction = 0.4
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seed = 42
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shuffle = False
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max_iter = 10
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clf1 = klass(
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early_stopping=True,
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random_state=np.random.RandomState(seed),
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validation_fraction=validation_fraction,
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learning_rate="constant",
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eta0=0.01,
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tol=None,
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max_iter=max_iter,
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shuffle=shuffle,
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)
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clf1.fit(X, Y)
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assert clf1.n_iter_ == max_iter
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clf2 = klass(
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early_stopping=False,
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random_state=np.random.RandomState(seed),
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learning_rate="constant",
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eta0=0.01,
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tol=None,
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max_iter=max_iter,
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shuffle=shuffle,
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)
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if is_classifier(clf2):
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cv = StratifiedShuffleSplit(test_size=validation_fraction, random_state=seed)
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else:
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cv = ShuffleSplit(test_size=validation_fraction, random_state=seed)
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idx_train, idx_val = next(cv.split(X, Y))
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idx_train = np.sort(idx_train) # remove shuffling
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clf2.fit(X[idx_train], Y[idx_train])
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assert clf2.n_iter_ == max_iter
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assert_array_equal(clf1.coef_, clf2.coef_)
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
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def test_n_iter_no_change(klass):
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X, Y = iris.data, iris.target
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# test that n_iter_ increases monotonically with n_iter_no_change
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for early_stopping in [True, False]:
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n_iter_list = [
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klass(
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early_stopping=early_stopping,
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n_iter_no_change=n_iter_no_change,
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tol=1e-4,
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max_iter=1000,
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)
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.fit(X, Y)
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.n_iter_
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for n_iter_no_change in [2, 3, 10]
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]
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assert_array_equal(n_iter_list, sorted(n_iter_list))
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@pytest.mark.parametrize(
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"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
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)
|
|
def test_not_enough_sample_for_early_stopping(klass):
|
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# test an error is raised if the training or validation set is empty
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clf = klass(early_stopping=True, validation_fraction=0.99)
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with pytest.raises(ValueError):
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clf.fit(X3, Y3)
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###############################################################################
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# Classification Test Case
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_clf(klass):
|
|
# Check that SGD gives any results :-)
|
|
|
|
for loss in ("hinge", "squared_hinge", "log_loss", "modified_huber"):
|
|
clf = klass(
|
|
penalty="l2",
|
|
alpha=0.01,
|
|
fit_intercept=True,
|
|
loss=loss,
|
|
max_iter=10,
|
|
shuffle=True,
|
|
)
|
|
clf.fit(X, Y)
|
|
# assert_almost_equal(clf.coef_[0], clf.coef_[1], decimal=7)
|
|
assert_array_equal(clf.predict(T), true_result)
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"klass", [SGDClassifier, SparseSGDClassifier, SGDOneClassSVM, SparseSGDOneClassSVM]
|
|
)
|
|
def test_provide_coef(klass):
|
|
"""Check that the shape of `coef_init` is validated."""
|
|
with pytest.raises(ValueError, match="Provided coef_init does not match dataset"):
|
|
klass().fit(X, Y, coef_init=np.zeros((3,)))
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"klass, fit_params",
|
|
[
|
|
(SGDClassifier, {"intercept_init": np.zeros((3,))}),
|
|
(SparseSGDClassifier, {"intercept_init": np.zeros((3,))}),
|
|
(SGDOneClassSVM, {"offset_init": np.zeros((3,))}),
|
|
(SparseSGDOneClassSVM, {"offset_init": np.zeros((3,))}),
|
|
],
|
|
)
|
|
def test_set_intercept_offset(klass, fit_params):
|
|
"""Check that `intercept_init` or `offset_init` is validated."""
|
|
sgd_estimator = klass()
|
|
with pytest.raises(ValueError, match="does not match dataset"):
|
|
sgd_estimator.fit(X, Y, **fit_params)
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"klass", [SGDClassifier, SparseSGDClassifier, SGDRegressor, SparseSGDRegressor]
|
|
)
|
|
def test_sgd_early_stopping_with_partial_fit(klass):
|
|
"""Check that we raise an error for `early_stopping` used with
|
|
`partial_fit`.
|
|
"""
|
|
err_msg = "early_stopping should be False with partial_fit"
|
|
with pytest.raises(ValueError, match=err_msg):
|
|
klass(early_stopping=True).partial_fit(X, Y)
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"klass, fit_params",
|
|
[
|
|
(SGDClassifier, {"intercept_init": 0}),
|
|
(SparseSGDClassifier, {"intercept_init": 0}),
|
|
(SGDOneClassSVM, {"offset_init": 0}),
|
|
(SparseSGDOneClassSVM, {"offset_init": 0}),
|
|
],
|
|
)
|
|
def test_set_intercept_offset_binary(klass, fit_params):
|
|
"""Check that we can pass a scaler with binary classification to
|
|
`intercept_init` or `offset_init`."""
|
|
klass().fit(X5, Y5, **fit_params)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_average_binary_computed_correctly(klass):
|
|
# Checks the SGDClassifier correctly computes the average weights
|
|
eta = 0.1
|
|
alpha = 2.0
|
|
n_samples = 20
|
|
n_features = 10
|
|
rng = np.random.RandomState(0)
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
w = rng.normal(size=n_features)
|
|
|
|
clf = klass(
|
|
loss="squared_error",
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
alpha=alpha,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
# simple linear function without noise
|
|
y = np.dot(X, w)
|
|
y = np.sign(y)
|
|
|
|
clf.fit(X, y)
|
|
|
|
average_weights, average_intercept = asgd(klass, X, y, eta, alpha)
|
|
average_weights = average_weights.reshape(1, -1)
|
|
assert_array_almost_equal(clf.coef_, average_weights, decimal=14)
|
|
assert_almost_equal(clf.intercept_, average_intercept, decimal=14)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_set_intercept_to_intercept(klass):
|
|
# Checks intercept_ shape consistency for the warm starts
|
|
# Inconsistent intercept_ shape.
|
|
clf = klass().fit(X5, Y5)
|
|
klass().fit(X5, Y5, intercept_init=clf.intercept_)
|
|
clf = klass().fit(X, Y)
|
|
klass().fit(X, Y, intercept_init=clf.intercept_)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_at_least_two_labels(klass):
|
|
# Target must have at least two labels
|
|
clf = klass(alpha=0.01, max_iter=20)
|
|
with pytest.raises(ValueError):
|
|
clf.fit(X2, np.ones(9))
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_partial_fit_weight_class_balanced(klass):
|
|
# partial_fit with class_weight='balanced' not supported"""
|
|
regex = (
|
|
r"class_weight 'balanced' is not supported for "
|
|
r"partial_fit\. In order to use 'balanced' weights, "
|
|
r"use compute_class_weight\('balanced', classes=classes, y=y\). "
|
|
r"In place of y you can use a large enough sample "
|
|
r"of the full training set target to properly "
|
|
r"estimate the class frequency distributions\. "
|
|
r"Pass the resulting weights as the class_weight "
|
|
r"parameter\."
|
|
)
|
|
with pytest.raises(ValueError, match=regex):
|
|
klass(class_weight="balanced").partial_fit(X, Y, classes=np.unique(Y))
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_multiclass(klass):
|
|
# Multi-class test case
|
|
clf = klass(alpha=0.01, max_iter=20).fit(X2, Y2)
|
|
assert clf.coef_.shape == (3, 2)
|
|
assert clf.intercept_.shape == (3,)
|
|
assert clf.decision_function([[0, 0]]).shape == (1, 3)
|
|
pred = clf.predict(T2)
|
|
assert_array_equal(pred, true_result2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_multiclass_average(klass):
|
|
eta = 0.001
|
|
alpha = 0.01
|
|
# Multi-class average test case
|
|
clf = klass(
|
|
loss="squared_error",
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
alpha=alpha,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
np_Y2 = np.array(Y2)
|
|
clf.fit(X2, np_Y2)
|
|
classes = np.unique(np_Y2)
|
|
|
|
for i, cl in enumerate(classes):
|
|
y_i = np.ones(np_Y2.shape[0])
|
|
y_i[np_Y2 != cl] = -1
|
|
average_coef, average_intercept = asgd(klass, X2, y_i, eta, alpha)
|
|
assert_array_almost_equal(average_coef, clf.coef_[i], decimal=16)
|
|
assert_almost_equal(average_intercept, clf.intercept_[i], decimal=16)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_multiclass_with_init_coef(klass):
|
|
# Multi-class test case
|
|
clf = klass(alpha=0.01, max_iter=20)
|
|
clf.fit(X2, Y2, coef_init=np.zeros((3, 2)), intercept_init=np.zeros(3))
|
|
assert clf.coef_.shape == (3, 2)
|
|
assert clf.intercept_.shape, (3,)
|
|
pred = clf.predict(T2)
|
|
assert_array_equal(pred, true_result2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_multiclass_njobs(klass):
|
|
# Multi-class test case with multi-core support
|
|
clf = klass(alpha=0.01, max_iter=20, n_jobs=2).fit(X2, Y2)
|
|
assert clf.coef_.shape == (3, 2)
|
|
assert clf.intercept_.shape == (3,)
|
|
assert clf.decision_function([[0, 0]]).shape == (1, 3)
|
|
pred = clf.predict(T2)
|
|
assert_array_equal(pred, true_result2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_set_coef_multiclass(klass):
|
|
# Checks coef_init and intercept_init shape for multi-class
|
|
# problems
|
|
# Provided coef_ does not match dataset
|
|
clf = klass()
|
|
with pytest.raises(ValueError):
|
|
clf.fit(X2, Y2, coef_init=np.zeros((2, 2)))
|
|
|
|
# Provided coef_ does match dataset
|
|
clf = klass().fit(X2, Y2, coef_init=np.zeros((3, 2)))
|
|
|
|
# Provided intercept_ does not match dataset
|
|
clf = klass()
|
|
with pytest.raises(ValueError):
|
|
clf.fit(X2, Y2, intercept_init=np.zeros((1,)))
|
|
|
|
# Provided intercept_ does match dataset.
|
|
clf = klass().fit(X2, Y2, intercept_init=np.zeros((3,)))
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_predict_proba_method_access(klass):
|
|
# Checks that SGDClassifier predict_proba and predict_log_proba methods
|
|
# can either be accessed or raise an appropriate error message
|
|
# otherwise. See
|
|
# https://github.com/scikit-learn/scikit-learn/issues/10938 for more
|
|
# details.
|
|
for loss in linear_model.SGDClassifier.loss_functions:
|
|
clf = SGDClassifier(loss=loss)
|
|
# TODO(1.3): Remove "log"
|
|
if loss in ("log_loss", "log", "modified_huber"):
|
|
assert hasattr(clf, "predict_proba")
|
|
assert hasattr(clf, "predict_log_proba")
|
|
else:
|
|
message = "probability estimates are not available for loss={!r}".format(
|
|
loss
|
|
)
|
|
assert not hasattr(clf, "predict_proba")
|
|
assert not hasattr(clf, "predict_log_proba")
|
|
with pytest.raises(AttributeError, match=message):
|
|
clf.predict_proba
|
|
with pytest.raises(AttributeError, match=message):
|
|
clf.predict_log_proba
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_proba(klass):
|
|
# Check SGD.predict_proba
|
|
|
|
# Hinge loss does not allow for conditional prob estimate.
|
|
# We cannot use the factory here, because it defines predict_proba
|
|
# anyway.
|
|
clf = SGDClassifier(loss="hinge", alpha=0.01, max_iter=10, tol=None).fit(X, Y)
|
|
assert not hasattr(clf, "predict_proba")
|
|
assert not hasattr(clf, "predict_log_proba")
|
|
|
|
# log and modified_huber losses can output probability estimates
|
|
# binary case
|
|
for loss in ["log_loss", "modified_huber"]:
|
|
clf = klass(loss=loss, alpha=0.01, max_iter=10)
|
|
clf.fit(X, Y)
|
|
p = clf.predict_proba([[3, 2]])
|
|
assert p[0, 1] > 0.5
|
|
p = clf.predict_proba([[-1, -1]])
|
|
assert p[0, 1] < 0.5
|
|
|
|
p = clf.predict_log_proba([[3, 2]])
|
|
assert p[0, 1] > p[0, 0]
|
|
p = clf.predict_log_proba([[-1, -1]])
|
|
assert p[0, 1] < p[0, 0]
|
|
|
|
# log loss multiclass probability estimates
|
|
clf = klass(loss="log_loss", alpha=0.01, max_iter=10).fit(X2, Y2)
|
|
|
|
d = clf.decision_function([[0.1, -0.1], [0.3, 0.2]])
|
|
p = clf.predict_proba([[0.1, -0.1], [0.3, 0.2]])
|
|
assert_array_equal(np.argmax(p, axis=1), np.argmax(d, axis=1))
|
|
assert_almost_equal(p[0].sum(), 1)
|
|
assert np.all(p[0] >= 0)
|
|
|
|
p = clf.predict_proba([[-1, -1]])
|
|
d = clf.decision_function([[-1, -1]])
|
|
assert_array_equal(np.argsort(p[0]), np.argsort(d[0]))
|
|
|
|
lp = clf.predict_log_proba([[3, 2]])
|
|
p = clf.predict_proba([[3, 2]])
|
|
assert_array_almost_equal(np.log(p), lp)
|
|
|
|
lp = clf.predict_log_proba([[-1, -1]])
|
|
p = clf.predict_proba([[-1, -1]])
|
|
assert_array_almost_equal(np.log(p), lp)
|
|
|
|
# Modified Huber multiclass probability estimates; requires a separate
|
|
# test because the hard zero/one probabilities may destroy the
|
|
# ordering present in decision_function output.
|
|
clf = klass(loss="modified_huber", alpha=0.01, max_iter=10)
|
|
clf.fit(X2, Y2)
|
|
d = clf.decision_function([[3, 2]])
|
|
p = clf.predict_proba([[3, 2]])
|
|
if klass != SparseSGDClassifier:
|
|
assert np.argmax(d, axis=1) == np.argmax(p, axis=1)
|
|
else: # XXX the sparse test gets a different X2 (?)
|
|
assert np.argmin(d, axis=1) == np.argmin(p, axis=1)
|
|
|
|
# the following sample produces decision_function values < -1,
|
|
# which would cause naive normalization to fail (see comment
|
|
# in SGDClassifier.predict_proba)
|
|
x = X.mean(axis=0)
|
|
d = clf.decision_function([x])
|
|
if np.all(d < -1): # XXX not true in sparse test case (why?)
|
|
p = clf.predict_proba([x])
|
|
assert_array_almost_equal(p[0], [1 / 3.0] * 3)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sgd_l1(klass):
|
|
# Test L1 regularization
|
|
n = len(X4)
|
|
rng = np.random.RandomState(13)
|
|
idx = np.arange(n)
|
|
rng.shuffle(idx)
|
|
|
|
X = X4[idx, :]
|
|
Y = Y4[idx]
|
|
|
|
clf = klass(
|
|
penalty="l1",
|
|
alpha=0.2,
|
|
fit_intercept=False,
|
|
max_iter=2000,
|
|
tol=None,
|
|
shuffle=False,
|
|
)
|
|
clf.fit(X, Y)
|
|
assert_array_equal(clf.coef_[0, 1:-1], np.zeros((4,)))
|
|
pred = clf.predict(X)
|
|
assert_array_equal(pred, Y)
|
|
|
|
# test sparsify with dense inputs
|
|
clf.sparsify()
|
|
assert sp.issparse(clf.coef_)
|
|
pred = clf.predict(X)
|
|
assert_array_equal(pred, Y)
|
|
|
|
# pickle and unpickle with sparse coef_
|
|
clf = pickle.loads(pickle.dumps(clf))
|
|
assert sp.issparse(clf.coef_)
|
|
pred = clf.predict(X)
|
|
assert_array_equal(pred, Y)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_class_weights(klass):
|
|
# Test class weights.
|
|
X = np.array([[-1.0, -1.0], [-1.0, 0], [-0.8, -1.0], [1.0, 1.0], [1.0, 0.0]])
|
|
y = [1, 1, 1, -1, -1]
|
|
|
|
clf = klass(alpha=0.1, max_iter=1000, fit_intercept=False, class_weight=None)
|
|
clf.fit(X, y)
|
|
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([1]))
|
|
|
|
# we give a small weights to class 1
|
|
clf = klass(alpha=0.1, max_iter=1000, fit_intercept=False, class_weight={1: 0.001})
|
|
clf.fit(X, y)
|
|
|
|
# now the hyperplane should rotate clock-wise and
|
|
# the prediction on this point should shift
|
|
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([-1]))
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_equal_class_weight(klass):
|
|
# Test if equal class weights approx. equals no class weights.
|
|
X = [[1, 0], [1, 0], [0, 1], [0, 1]]
|
|
y = [0, 0, 1, 1]
|
|
clf = klass(alpha=0.1, max_iter=1000, class_weight=None)
|
|
clf.fit(X, y)
|
|
|
|
X = [[1, 0], [0, 1]]
|
|
y = [0, 1]
|
|
clf_weighted = klass(alpha=0.1, max_iter=1000, class_weight={0: 0.5, 1: 0.5})
|
|
clf_weighted.fit(X, y)
|
|
|
|
# should be similar up to some epsilon due to learning rate schedule
|
|
assert_almost_equal(clf.coef_, clf_weighted.coef_, decimal=2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_wrong_class_weight_label(klass):
|
|
# ValueError due to not existing class label.
|
|
clf = klass(alpha=0.1, max_iter=1000, class_weight={0: 0.5})
|
|
with pytest.raises(ValueError):
|
|
clf.fit(X, Y)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_weights_multiplied(klass):
|
|
# Tests that class_weight and sample_weight are multiplicative
|
|
class_weights = {1: 0.6, 2: 0.3}
|
|
rng = np.random.RandomState(0)
|
|
sample_weights = rng.random_sample(Y4.shape[0])
|
|
multiplied_together = np.copy(sample_weights)
|
|
multiplied_together[Y4 == 1] *= class_weights[1]
|
|
multiplied_together[Y4 == 2] *= class_weights[2]
|
|
|
|
clf1 = klass(alpha=0.1, max_iter=20, class_weight=class_weights)
|
|
clf2 = klass(alpha=0.1, max_iter=20)
|
|
|
|
clf1.fit(X4, Y4, sample_weight=sample_weights)
|
|
clf2.fit(X4, Y4, sample_weight=multiplied_together)
|
|
|
|
assert_almost_equal(clf1.coef_, clf2.coef_)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_balanced_weight(klass):
|
|
# Test class weights for imbalanced data"""
|
|
# compute reference metrics on iris dataset that is quite balanced by
|
|
# default
|
|
X, y = iris.data, iris.target
|
|
X = scale(X)
|
|
idx = np.arange(X.shape[0])
|
|
rng = np.random.RandomState(6)
|
|
rng.shuffle(idx)
|
|
X = X[idx]
|
|
y = y[idx]
|
|
clf = klass(alpha=0.0001, max_iter=1000, class_weight=None, shuffle=False).fit(X, y)
|
|
f1 = metrics.f1_score(y, clf.predict(X), average="weighted")
|
|
assert_almost_equal(f1, 0.96, decimal=1)
|
|
|
|
# make the same prediction using balanced class_weight
|
|
clf_balanced = klass(
|
|
alpha=0.0001, max_iter=1000, class_weight="balanced", shuffle=False
|
|
).fit(X, y)
|
|
f1 = metrics.f1_score(y, clf_balanced.predict(X), average="weighted")
|
|
assert_almost_equal(f1, 0.96, decimal=1)
|
|
|
|
# Make sure that in the balanced case it does not change anything
|
|
# to use "balanced"
|
|
assert_array_almost_equal(clf.coef_, clf_balanced.coef_, 6)
|
|
|
|
# build an very very imbalanced dataset out of iris data
|
|
X_0 = X[y == 0, :]
|
|
y_0 = y[y == 0]
|
|
|
|
X_imbalanced = np.vstack([X] + [X_0] * 10)
|
|
y_imbalanced = np.concatenate([y] + [y_0] * 10)
|
|
|
|
# fit a model on the imbalanced data without class weight info
|
|
clf = klass(max_iter=1000, class_weight=None, shuffle=False)
|
|
clf.fit(X_imbalanced, y_imbalanced)
|
|
y_pred = clf.predict(X)
|
|
assert metrics.f1_score(y, y_pred, average="weighted") < 0.96
|
|
|
|
# fit a model with balanced class_weight enabled
|
|
clf = klass(max_iter=1000, class_weight="balanced", shuffle=False)
|
|
clf.fit(X_imbalanced, y_imbalanced)
|
|
y_pred = clf.predict(X)
|
|
assert metrics.f1_score(y, y_pred, average="weighted") > 0.96
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_sample_weights(klass):
|
|
# Test weights on individual samples
|
|
X = np.array([[-1.0, -1.0], [-1.0, 0], [-0.8, -1.0], [1.0, 1.0], [1.0, 0.0]])
|
|
y = [1, 1, 1, -1, -1]
|
|
|
|
clf = klass(alpha=0.1, max_iter=1000, fit_intercept=False)
|
|
clf.fit(X, y)
|
|
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([1]))
|
|
|
|
# we give a small weights to class 1
|
|
clf.fit(X, y, sample_weight=[0.001] * 3 + [1] * 2)
|
|
|
|
# now the hyperplane should rotate clock-wise and
|
|
# the prediction on this point should shift
|
|
assert_array_equal(clf.predict([[0.2, -1.0]]), np.array([-1]))
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"klass", [SGDClassifier, SparseSGDClassifier, SGDOneClassSVM, SparseSGDOneClassSVM]
|
|
)
|
|
def test_wrong_sample_weights(klass):
|
|
# Test if ValueError is raised if sample_weight has wrong shape
|
|
if klass in [SGDClassifier, SparseSGDClassifier]:
|
|
clf = klass(alpha=0.1, max_iter=1000, fit_intercept=False)
|
|
elif klass in [SGDOneClassSVM, SparseSGDOneClassSVM]:
|
|
clf = klass(nu=0.1, max_iter=1000, fit_intercept=False)
|
|
# provided sample_weight too long
|
|
with pytest.raises(ValueError):
|
|
clf.fit(X, Y, sample_weight=np.arange(7))
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_partial_fit_exception(klass):
|
|
clf = klass(alpha=0.01)
|
|
# classes was not specified
|
|
with pytest.raises(ValueError):
|
|
clf.partial_fit(X3, Y3)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_partial_fit_binary(klass):
|
|
third = X.shape[0] // 3
|
|
clf = klass(alpha=0.01)
|
|
classes = np.unique(Y)
|
|
|
|
clf.partial_fit(X[:third], Y[:third], classes=classes)
|
|
assert clf.coef_.shape == (1, X.shape[1])
|
|
assert clf.intercept_.shape == (1,)
|
|
assert clf.decision_function([[0, 0]]).shape == (1,)
|
|
id1 = id(clf.coef_.data)
|
|
|
|
clf.partial_fit(X[third:], Y[third:])
|
|
id2 = id(clf.coef_.data)
|
|
# check that coef_ haven't been re-allocated
|
|
assert id1, id2
|
|
|
|
y_pred = clf.predict(T)
|
|
assert_array_equal(y_pred, true_result)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_partial_fit_multiclass(klass):
|
|
third = X2.shape[0] // 3
|
|
clf = klass(alpha=0.01)
|
|
classes = np.unique(Y2)
|
|
|
|
clf.partial_fit(X2[:third], Y2[:third], classes=classes)
|
|
assert clf.coef_.shape == (3, X2.shape[1])
|
|
assert clf.intercept_.shape == (3,)
|
|
assert clf.decision_function([[0, 0]]).shape == (1, 3)
|
|
id1 = id(clf.coef_.data)
|
|
|
|
clf.partial_fit(X2[third:], Y2[third:])
|
|
id2 = id(clf.coef_.data)
|
|
# check that coef_ haven't been re-allocated
|
|
assert id1, id2
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_partial_fit_multiclass_average(klass):
|
|
third = X2.shape[0] // 3
|
|
clf = klass(alpha=0.01, average=X2.shape[0])
|
|
classes = np.unique(Y2)
|
|
|
|
clf.partial_fit(X2[:third], Y2[:third], classes=classes)
|
|
assert clf.coef_.shape == (3, X2.shape[1])
|
|
assert clf.intercept_.shape == (3,)
|
|
|
|
clf.partial_fit(X2[third:], Y2[third:])
|
|
assert clf.coef_.shape == (3, X2.shape[1])
|
|
assert clf.intercept_.shape == (3,)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_fit_then_partial_fit(klass):
|
|
# Partial_fit should work after initial fit in the multiclass case.
|
|
# Non-regression test for #2496; fit would previously produce a
|
|
# Fortran-ordered coef_ that subsequent partial_fit couldn't handle.
|
|
clf = klass()
|
|
clf.fit(X2, Y2)
|
|
clf.partial_fit(X2, Y2) # no exception here
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
@pytest.mark.parametrize("lr", ["constant", "optimal", "invscaling", "adaptive"])
|
|
def test_partial_fit_equal_fit_classif(klass, lr):
|
|
for X_, Y_, T_ in ((X, Y, T), (X2, Y2, T2)):
|
|
clf = klass(alpha=0.01, eta0=0.01, max_iter=2, learning_rate=lr, shuffle=False)
|
|
clf.fit(X_, Y_)
|
|
y_pred = clf.decision_function(T_)
|
|
t = clf.t_
|
|
|
|
classes = np.unique(Y_)
|
|
clf = klass(alpha=0.01, eta0=0.01, learning_rate=lr, shuffle=False)
|
|
for i in range(2):
|
|
clf.partial_fit(X_, Y_, classes=classes)
|
|
y_pred2 = clf.decision_function(T_)
|
|
|
|
assert clf.t_ == t
|
|
assert_array_almost_equal(y_pred, y_pred2, decimal=2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_regression_losses(klass):
|
|
random_state = np.random.RandomState(1)
|
|
clf = klass(
|
|
alpha=0.01,
|
|
learning_rate="constant",
|
|
eta0=0.1,
|
|
loss="epsilon_insensitive",
|
|
random_state=random_state,
|
|
)
|
|
clf.fit(X, Y)
|
|
assert 1.0 == np.mean(clf.predict(X) == Y)
|
|
|
|
clf = klass(
|
|
alpha=0.01,
|
|
learning_rate="constant",
|
|
eta0=0.1,
|
|
loss="squared_epsilon_insensitive",
|
|
random_state=random_state,
|
|
)
|
|
clf.fit(X, Y)
|
|
assert 1.0 == np.mean(clf.predict(X) == Y)
|
|
|
|
clf = klass(alpha=0.01, loss="huber", random_state=random_state)
|
|
clf.fit(X, Y)
|
|
assert 1.0 == np.mean(clf.predict(X) == Y)
|
|
|
|
clf = klass(
|
|
alpha=0.01,
|
|
learning_rate="constant",
|
|
eta0=0.01,
|
|
loss="squared_error",
|
|
random_state=random_state,
|
|
)
|
|
clf.fit(X, Y)
|
|
assert 1.0 == np.mean(clf.predict(X) == Y)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_warm_start_multiclass(klass):
|
|
_test_warm_start(klass, X2, Y2, "optimal")
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDClassifier, SparseSGDClassifier])
|
|
def test_multiple_fit(klass):
|
|
# Test multiple calls of fit w/ different shaped inputs.
|
|
clf = klass(alpha=0.01, shuffle=False)
|
|
clf.fit(X, Y)
|
|
assert hasattr(clf, "coef_")
|
|
|
|
# Non-regression test: try fitting with a different label set.
|
|
y = [["ham", "spam"][i] for i in LabelEncoder().fit_transform(Y)]
|
|
clf.fit(X[:, :-1], y)
|
|
|
|
|
|
###############################################################################
|
|
# Regression Test Case
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_reg(klass):
|
|
# Check that SGD gives any results.
|
|
clf = klass(alpha=0.1, max_iter=2, fit_intercept=False)
|
|
clf.fit([[0, 0], [1, 1], [2, 2]], [0, 1, 2])
|
|
assert clf.coef_[0] == clf.coef_[1]
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_averaged_computed_correctly(klass):
|
|
# Tests the average regressor matches the naive implementation
|
|
|
|
eta = 0.001
|
|
alpha = 0.01
|
|
n_samples = 20
|
|
n_features = 10
|
|
rng = np.random.RandomState(0)
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
w = rng.normal(size=n_features)
|
|
|
|
# simple linear function without noise
|
|
y = np.dot(X, w)
|
|
|
|
clf = klass(
|
|
loss="squared_error",
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
alpha=alpha,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
clf.fit(X, y)
|
|
average_weights, average_intercept = asgd(klass, X, y, eta, alpha)
|
|
|
|
assert_array_almost_equal(clf.coef_, average_weights, decimal=16)
|
|
assert_almost_equal(clf.intercept_, average_intercept, decimal=16)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_averaged_partial_fit(klass):
|
|
# Tests whether the partial fit yields the same average as the fit
|
|
eta = 0.001
|
|
alpha = 0.01
|
|
n_samples = 20
|
|
n_features = 10
|
|
rng = np.random.RandomState(0)
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
w = rng.normal(size=n_features)
|
|
|
|
# simple linear function without noise
|
|
y = np.dot(X, w)
|
|
|
|
clf = klass(
|
|
loss="squared_error",
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
alpha=alpha,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
clf.partial_fit(X[: int(n_samples / 2)][:], y[: int(n_samples / 2)])
|
|
clf.partial_fit(X[int(n_samples / 2) :][:], y[int(n_samples / 2) :])
|
|
average_weights, average_intercept = asgd(klass, X, y, eta, alpha)
|
|
|
|
assert_array_almost_equal(clf.coef_, average_weights, decimal=16)
|
|
assert_almost_equal(clf.intercept_[0], average_intercept, decimal=16)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_average_sparse(klass):
|
|
# Checks the average weights on data with 0s
|
|
|
|
eta = 0.001
|
|
alpha = 0.01
|
|
clf = klass(
|
|
loss="squared_error",
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
alpha=alpha,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
n_samples = Y3.shape[0]
|
|
|
|
clf.partial_fit(X3[: int(n_samples / 2)][:], Y3[: int(n_samples / 2)])
|
|
clf.partial_fit(X3[int(n_samples / 2) :][:], Y3[int(n_samples / 2) :])
|
|
average_weights, average_intercept = asgd(klass, X3, Y3, eta, alpha)
|
|
|
|
assert_array_almost_equal(clf.coef_, average_weights, decimal=16)
|
|
assert_almost_equal(clf.intercept_, average_intercept, decimal=16)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_least_squares_fit(klass):
|
|
xmin, xmax = -5, 5
|
|
n_samples = 100
|
|
rng = np.random.RandomState(0)
|
|
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
|
|
|
|
# simple linear function without noise
|
|
y = 0.5 * X.ravel()
|
|
|
|
clf = klass(loss="squared_error", alpha=0.1, max_iter=20, fit_intercept=False)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.99
|
|
|
|
# simple linear function with noise
|
|
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
|
|
|
|
clf = klass(loss="squared_error", alpha=0.1, max_iter=20, fit_intercept=False)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.5
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_epsilon_insensitive(klass):
|
|
xmin, xmax = -5, 5
|
|
n_samples = 100
|
|
rng = np.random.RandomState(0)
|
|
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
|
|
|
|
# simple linear function without noise
|
|
y = 0.5 * X.ravel()
|
|
|
|
clf = klass(
|
|
loss="epsilon_insensitive",
|
|
epsilon=0.01,
|
|
alpha=0.1,
|
|
max_iter=20,
|
|
fit_intercept=False,
|
|
)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.99
|
|
|
|
# simple linear function with noise
|
|
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
|
|
|
|
clf = klass(
|
|
loss="epsilon_insensitive",
|
|
epsilon=0.01,
|
|
alpha=0.1,
|
|
max_iter=20,
|
|
fit_intercept=False,
|
|
)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.5
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_sgd_huber_fit(klass):
|
|
xmin, xmax = -5, 5
|
|
n_samples = 100
|
|
rng = np.random.RandomState(0)
|
|
X = np.linspace(xmin, xmax, n_samples).reshape(n_samples, 1)
|
|
|
|
# simple linear function without noise
|
|
y = 0.5 * X.ravel()
|
|
|
|
clf = klass(loss="huber", epsilon=0.1, alpha=0.1, max_iter=20, fit_intercept=False)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.99
|
|
|
|
# simple linear function with noise
|
|
y = 0.5 * X.ravel() + rng.randn(n_samples, 1).ravel()
|
|
|
|
clf = klass(loss="huber", epsilon=0.1, alpha=0.1, max_iter=20, fit_intercept=False)
|
|
clf.fit(X, y)
|
|
score = clf.score(X, y)
|
|
assert score > 0.5
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_elasticnet_convergence(klass):
|
|
# Check that the SGD output is consistent with coordinate descent
|
|
|
|
n_samples, n_features = 1000, 5
|
|
rng = np.random.RandomState(0)
|
|
X = rng.randn(n_samples, n_features)
|
|
# ground_truth linear model that generate y from X and to which the
|
|
# models should converge if the regularizer would be set to 0.0
|
|
ground_truth_coef = rng.randn(n_features)
|
|
y = np.dot(X, ground_truth_coef)
|
|
|
|
# XXX: alpha = 0.1 seems to cause convergence problems
|
|
for alpha in [0.01, 0.001]:
|
|
for l1_ratio in [0.5, 0.8, 1.0]:
|
|
cd = linear_model.ElasticNet(
|
|
alpha=alpha, l1_ratio=l1_ratio, fit_intercept=False
|
|
)
|
|
cd.fit(X, y)
|
|
sgd = klass(
|
|
penalty="elasticnet",
|
|
max_iter=50,
|
|
alpha=alpha,
|
|
l1_ratio=l1_ratio,
|
|
fit_intercept=False,
|
|
)
|
|
sgd.fit(X, y)
|
|
err_msg = (
|
|
"cd and sgd did not converge to comparable "
|
|
"results for alpha=%f and l1_ratio=%f" % (alpha, l1_ratio)
|
|
)
|
|
assert_almost_equal(cd.coef_, sgd.coef_, decimal=2, err_msg=err_msg)
|
|
|
|
|
|
@ignore_warnings
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_partial_fit(klass):
|
|
third = X.shape[0] // 3
|
|
clf = klass(alpha=0.01)
|
|
|
|
clf.partial_fit(X[:third], Y[:third])
|
|
assert clf.coef_.shape == (X.shape[1],)
|
|
assert clf.intercept_.shape == (1,)
|
|
assert clf.predict([[0, 0]]).shape == (1,)
|
|
id1 = id(clf.coef_.data)
|
|
|
|
clf.partial_fit(X[third:], Y[third:])
|
|
id2 = id(clf.coef_.data)
|
|
# check that coef_ haven't been re-allocated
|
|
assert id1, id2
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
@pytest.mark.parametrize("lr", ["constant", "optimal", "invscaling", "adaptive"])
|
|
def test_partial_fit_equal_fit(klass, lr):
|
|
clf = klass(alpha=0.01, max_iter=2, eta0=0.01, learning_rate=lr, shuffle=False)
|
|
clf.fit(X, Y)
|
|
y_pred = clf.predict(T)
|
|
t = clf.t_
|
|
|
|
clf = klass(alpha=0.01, eta0=0.01, learning_rate=lr, shuffle=False)
|
|
for i in range(2):
|
|
clf.partial_fit(X, Y)
|
|
y_pred2 = clf.predict(T)
|
|
|
|
assert clf.t_ == t
|
|
assert_array_almost_equal(y_pred, y_pred2, decimal=2)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDRegressor, SparseSGDRegressor])
|
|
def test_loss_function_epsilon(klass):
|
|
clf = klass(epsilon=0.9)
|
|
clf.set_params(epsilon=0.1)
|
|
assert clf.loss_functions["huber"][1] == 0.1
|
|
|
|
|
|
###############################################################################
|
|
# SGD One Class SVM Test Case
|
|
|
|
# a simple implementation of ASGD to use for testing SGDOneClassSVM
|
|
def asgd_oneclass(klass, X, eta, nu, coef_init=None, offset_init=0.0):
|
|
if coef_init is None:
|
|
coef = np.zeros(X.shape[1])
|
|
else:
|
|
coef = coef_init
|
|
|
|
average_coef = np.zeros(X.shape[1])
|
|
offset = offset_init
|
|
intercept = 1 - offset
|
|
average_intercept = 0.0
|
|
decay = 1.0
|
|
|
|
# sparse data has a fixed decay of .01
|
|
if klass == SparseSGDOneClassSVM:
|
|
decay = 0.01
|
|
|
|
for i, entry in enumerate(X):
|
|
p = np.dot(entry, coef)
|
|
p += intercept
|
|
if p <= 1.0:
|
|
gradient = -1
|
|
else:
|
|
gradient = 0
|
|
coef *= max(0, 1.0 - (eta * nu / 2))
|
|
coef += -(eta * gradient * entry)
|
|
intercept += -(eta * (nu + gradient)) * decay
|
|
|
|
average_coef *= i
|
|
average_coef += coef
|
|
average_coef /= i + 1.0
|
|
|
|
average_intercept *= i
|
|
average_intercept += intercept
|
|
average_intercept /= i + 1.0
|
|
|
|
return average_coef, 1 - average_intercept
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def _test_warm_start_oneclass(klass, X, lr):
|
|
# Test that explicit warm restart...
|
|
clf = klass(nu=0.5, eta0=0.01, shuffle=False, learning_rate=lr)
|
|
clf.fit(X)
|
|
|
|
clf2 = klass(nu=0.1, eta0=0.01, shuffle=False, learning_rate=lr)
|
|
clf2.fit(X, coef_init=clf.coef_.copy(), offset_init=clf.offset_.copy())
|
|
|
|
# ... and implicit warm restart are equivalent.
|
|
clf3 = klass(nu=0.5, eta0=0.01, shuffle=False, warm_start=True, learning_rate=lr)
|
|
clf3.fit(X)
|
|
|
|
assert clf3.t_ == clf.t_
|
|
assert_allclose(clf3.coef_, clf.coef_)
|
|
|
|
clf3.set_params(nu=0.1)
|
|
clf3.fit(X)
|
|
|
|
assert clf3.t_ == clf2.t_
|
|
assert_allclose(clf3.coef_, clf2.coef_)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
@pytest.mark.parametrize("lr", ["constant", "optimal", "invscaling", "adaptive"])
|
|
def test_warm_start_oneclass(klass, lr):
|
|
_test_warm_start_oneclass(klass, X, lr)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_clone_oneclass(klass):
|
|
# Test whether clone works ok.
|
|
clf = klass(nu=0.5)
|
|
clf = clone(clf)
|
|
clf.set_params(nu=0.1)
|
|
clf.fit(X)
|
|
|
|
clf2 = klass(nu=0.1)
|
|
clf2.fit(X)
|
|
|
|
assert_array_equal(clf.coef_, clf2.coef_)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_partial_fit_oneclass(klass):
|
|
third = X.shape[0] // 3
|
|
clf = klass(nu=0.1)
|
|
|
|
clf.partial_fit(X[:third])
|
|
assert clf.coef_.shape == (X.shape[1],)
|
|
assert clf.offset_.shape == (1,)
|
|
assert clf.predict([[0, 0]]).shape == (1,)
|
|
previous_coefs = clf.coef_
|
|
|
|
clf.partial_fit(X[third:])
|
|
# check that coef_ haven't been re-allocated
|
|
assert clf.coef_ is previous_coefs
|
|
|
|
# raises ValueError if number of features does not match previous data
|
|
with pytest.raises(ValueError):
|
|
clf.partial_fit(X[:, 1])
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
@pytest.mark.parametrize("lr", ["constant", "optimal", "invscaling", "adaptive"])
|
|
def test_partial_fit_equal_fit_oneclass(klass, lr):
|
|
clf = klass(nu=0.05, max_iter=2, eta0=0.01, learning_rate=lr, shuffle=False)
|
|
clf.fit(X)
|
|
y_scores = clf.decision_function(T)
|
|
t = clf.t_
|
|
coef = clf.coef_
|
|
offset = clf.offset_
|
|
|
|
clf = klass(nu=0.05, eta0=0.01, max_iter=1, learning_rate=lr, shuffle=False)
|
|
for _ in range(2):
|
|
clf.partial_fit(X)
|
|
y_scores2 = clf.decision_function(T)
|
|
|
|
assert clf.t_ == t
|
|
assert_allclose(y_scores, y_scores2)
|
|
assert_allclose(clf.coef_, coef)
|
|
assert_allclose(clf.offset_, offset)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_late_onset_averaging_reached_oneclass(klass):
|
|
# Test average
|
|
eta0 = 0.001
|
|
nu = 0.05
|
|
|
|
# 2 passes over the training set but average only at second pass
|
|
clf1 = klass(
|
|
average=7, learning_rate="constant", eta0=eta0, nu=nu, max_iter=2, shuffle=False
|
|
)
|
|
# 1 pass over the training set with no averaging
|
|
clf2 = klass(
|
|
average=0, learning_rate="constant", eta0=eta0, nu=nu, max_iter=1, shuffle=False
|
|
)
|
|
|
|
clf1.fit(X)
|
|
clf2.fit(X)
|
|
|
|
# Start from clf2 solution, compute averaging using asgd function and
|
|
# compare with clf1 solution
|
|
average_coef, average_offset = asgd_oneclass(
|
|
klass, X, eta0, nu, coef_init=clf2.coef_.ravel(), offset_init=clf2.offset_
|
|
)
|
|
|
|
assert_allclose(clf1.coef_.ravel(), average_coef.ravel())
|
|
assert_allclose(clf1.offset_, average_offset)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_sgd_averaged_computed_correctly_oneclass(klass):
|
|
# Tests the average SGD One-Class SVM matches the naive implementation
|
|
eta = 0.001
|
|
nu = 0.05
|
|
n_samples = 20
|
|
n_features = 10
|
|
rng = np.random.RandomState(0)
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
|
|
clf = klass(
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
nu=nu,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
clf.fit(X)
|
|
average_coef, average_offset = asgd_oneclass(klass, X, eta, nu)
|
|
|
|
assert_allclose(clf.coef_, average_coef)
|
|
assert_allclose(clf.offset_, average_offset)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_sgd_averaged_partial_fit_oneclass(klass):
|
|
# Tests whether the partial fit yields the same average as the fit
|
|
eta = 0.001
|
|
nu = 0.05
|
|
n_samples = 20
|
|
n_features = 10
|
|
rng = np.random.RandomState(0)
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
|
|
clf = klass(
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
nu=nu,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
clf.partial_fit(X[: int(n_samples / 2)][:])
|
|
clf.partial_fit(X[int(n_samples / 2) :][:])
|
|
average_coef, average_offset = asgd_oneclass(klass, X, eta, nu)
|
|
|
|
assert_allclose(clf.coef_, average_coef)
|
|
assert_allclose(clf.offset_, average_offset)
|
|
|
|
|
|
@pytest.mark.parametrize("klass", [SGDOneClassSVM, SparseSGDOneClassSVM])
|
|
def test_average_sparse_oneclass(klass):
|
|
# Checks the average coef on data with 0s
|
|
eta = 0.001
|
|
nu = 0.01
|
|
clf = klass(
|
|
learning_rate="constant",
|
|
eta0=eta,
|
|
nu=nu,
|
|
fit_intercept=True,
|
|
max_iter=1,
|
|
average=True,
|
|
shuffle=False,
|
|
)
|
|
|
|
n_samples = X3.shape[0]
|
|
|
|
clf.partial_fit(X3[: int(n_samples / 2)])
|
|
clf.partial_fit(X3[int(n_samples / 2) :])
|
|
average_coef, average_offset = asgd_oneclass(klass, X3, eta, nu)
|
|
|
|
assert_allclose(clf.coef_, average_coef)
|
|
assert_allclose(clf.offset_, average_offset)
|
|
|
|
|
|
def test_sgd_oneclass():
|
|
# Test fit, decision_function, predict and score_samples on a toy
|
|
# dataset
|
|
X_train = np.array([[-2, -1], [-1, -1], [1, 1]])
|
|
X_test = np.array([[0.5, -2], [2, 2]])
|
|
clf = SGDOneClassSVM(
|
|
nu=0.5, eta0=1, learning_rate="constant", shuffle=False, max_iter=1
|
|
)
|
|
clf.fit(X_train)
|
|
assert_allclose(clf.coef_, np.array([-0.125, 0.4375]))
|
|
assert clf.offset_[0] == -0.5
|
|
|
|
scores = clf.score_samples(X_test)
|
|
assert_allclose(scores, np.array([-0.9375, 0.625]))
|
|
|
|
dec = clf.score_samples(X_test) - clf.offset_
|
|
assert_allclose(clf.decision_function(X_test), dec)
|
|
|
|
pred = clf.predict(X_test)
|
|
assert_array_equal(pred, np.array([-1, 1]))
|
|
|
|
|
|
def test_ocsvm_vs_sgdocsvm():
|
|
# Checks SGDOneClass SVM gives a good approximation of kernelized
|
|
# One-Class SVM
|
|
nu = 0.05
|
|
gamma = 2.0
|
|
random_state = 42
|
|
|
|
# Generate train and test data
|
|
rng = np.random.RandomState(random_state)
|
|
X = 0.3 * rng.randn(500, 2)
|
|
X_train = np.r_[X + 2, X - 2]
|
|
X = 0.3 * rng.randn(100, 2)
|
|
X_test = np.r_[X + 2, X - 2]
|
|
|
|
# One-Class SVM
|
|
clf = OneClassSVM(gamma=gamma, kernel="rbf", nu=nu)
|
|
clf.fit(X_train)
|
|
y_pred_ocsvm = clf.predict(X_test)
|
|
dec_ocsvm = clf.decision_function(X_test).reshape(1, -1)
|
|
|
|
# SGDOneClassSVM using kernel approximation
|
|
max_iter = 15
|
|
transform = Nystroem(gamma=gamma, random_state=random_state)
|
|
clf_sgd = SGDOneClassSVM(
|
|
nu=nu,
|
|
shuffle=True,
|
|
fit_intercept=True,
|
|
max_iter=max_iter,
|
|
random_state=random_state,
|
|
tol=None,
|
|
)
|
|
pipe_sgd = make_pipeline(transform, clf_sgd)
|
|
pipe_sgd.fit(X_train)
|
|
y_pred_sgdocsvm = pipe_sgd.predict(X_test)
|
|
dec_sgdocsvm = pipe_sgd.decision_function(X_test).reshape(1, -1)
|
|
|
|
assert np.mean(y_pred_sgdocsvm == y_pred_ocsvm) >= 0.99
|
|
corrcoef = np.corrcoef(np.concatenate((dec_ocsvm, dec_sgdocsvm)))[0, 1]
|
|
assert corrcoef >= 0.9
|
|
|
|
|
|
def test_l1_ratio():
|
|
# Test if l1 ratio extremes match L1 and L2 penalty settings.
|
|
X, y = datasets.make_classification(
|
|
n_samples=1000, n_features=100, n_informative=20, random_state=1234
|
|
)
|
|
|
|
# test if elasticnet with l1_ratio near 1 gives same result as pure l1
|
|
est_en = SGDClassifier(
|
|
alpha=0.001,
|
|
penalty="elasticnet",
|
|
tol=None,
|
|
max_iter=6,
|
|
l1_ratio=0.9999999999,
|
|
random_state=42,
|
|
).fit(X, y)
|
|
est_l1 = SGDClassifier(
|
|
alpha=0.001, penalty="l1", max_iter=6, random_state=42, tol=None
|
|
).fit(X, y)
|
|
assert_array_almost_equal(est_en.coef_, est_l1.coef_)
|
|
|
|
# test if elasticnet with l1_ratio near 0 gives same result as pure l2
|
|
est_en = SGDClassifier(
|
|
alpha=0.001,
|
|
penalty="elasticnet",
|
|
tol=None,
|
|
max_iter=6,
|
|
l1_ratio=0.0000000001,
|
|
random_state=42,
|
|
).fit(X, y)
|
|
est_l2 = SGDClassifier(
|
|
alpha=0.001, penalty="l2", max_iter=6, random_state=42, tol=None
|
|
).fit(X, y)
|
|
assert_array_almost_equal(est_en.coef_, est_l2.coef_)
|
|
|
|
|
|
def test_underflow_or_overlow():
|
|
with np.errstate(all="raise"):
|
|
# Generate some weird data with hugely unscaled features
|
|
rng = np.random.RandomState(0)
|
|
n_samples = 100
|
|
n_features = 10
|
|
|
|
X = rng.normal(size=(n_samples, n_features))
|
|
X[:, :2] *= 1e300
|
|
assert np.isfinite(X).all()
|
|
|
|
# Use MinMaxScaler to scale the data without introducing a numerical
|
|
# instability (computing the standard deviation naively is not possible
|
|
# on this data)
|
|
X_scaled = MinMaxScaler().fit_transform(X)
|
|
assert np.isfinite(X_scaled).all()
|
|
|
|
# Define a ground truth on the scaled data
|
|
ground_truth = rng.normal(size=n_features)
|
|
y = (np.dot(X_scaled, ground_truth) > 0.0).astype(np.int32)
|
|
assert_array_equal(np.unique(y), [0, 1])
|
|
|
|
model = SGDClassifier(alpha=0.1, loss="squared_hinge", max_iter=500)
|
|
|
|
# smoke test: model is stable on scaled data
|
|
model.fit(X_scaled, y)
|
|
assert np.isfinite(model.coef_).all()
|
|
|
|
# model is numerically unstable on unscaled data
|
|
msg_regxp = (
|
|
r"Floating-point under-/overflow occurred at epoch #.*"
|
|
" Scaling input data with StandardScaler or MinMaxScaler"
|
|
" might help."
|
|
)
|
|
with pytest.raises(ValueError, match=msg_regxp):
|
|
model.fit(X, y)
|
|
|
|
|
|
def test_numerical_stability_large_gradient():
|
|
# Non regression test case for numerical stability on scaled problems
|
|
# where the gradient can still explode with some losses
|
|
model = SGDClassifier(
|
|
loss="squared_hinge",
|
|
max_iter=10,
|
|
shuffle=True,
|
|
penalty="elasticnet",
|
|
l1_ratio=0.3,
|
|
alpha=0.01,
|
|
eta0=0.001,
|
|
random_state=0,
|
|
tol=None,
|
|
)
|
|
with np.errstate(all="raise"):
|
|
model.fit(iris.data, iris.target)
|
|
assert np.isfinite(model.coef_).all()
|
|
|
|
|
|
@pytest.mark.parametrize("penalty", ["l2", "l1", "elasticnet"])
|
|
def test_large_regularization(penalty):
|
|
# Non regression tests for numerical stability issues caused by large
|
|
# regularization parameters
|
|
model = SGDClassifier(
|
|
alpha=1e5,
|
|
learning_rate="constant",
|
|
eta0=0.1,
|
|
penalty=penalty,
|
|
shuffle=False,
|
|
tol=None,
|
|
max_iter=6,
|
|
)
|
|
with np.errstate(all="raise"):
|
|
model.fit(iris.data, iris.target)
|
|
assert_array_almost_equal(model.coef_, np.zeros_like(model.coef_))
|
|
|
|
|
|
def test_tol_parameter():
|
|
# Test that the tol parameter behaves as expected
|
|
X = StandardScaler().fit_transform(iris.data)
|
|
y = iris.target == 1
|
|
|
|
# With tol is None, the number of iteration should be equal to max_iter
|
|
max_iter = 42
|
|
model_0 = SGDClassifier(tol=None, random_state=0, max_iter=max_iter)
|
|
model_0.fit(X, y)
|
|
assert max_iter == model_0.n_iter_
|
|
|
|
# If tol is not None, the number of iteration should be less than max_iter
|
|
max_iter = 2000
|
|
model_1 = SGDClassifier(tol=0, random_state=0, max_iter=max_iter)
|
|
model_1.fit(X, y)
|
|
assert max_iter > model_1.n_iter_
|
|
assert model_1.n_iter_ > 5
|
|
|
|
# A larger tol should yield a smaller number of iteration
|
|
model_2 = SGDClassifier(tol=0.1, random_state=0, max_iter=max_iter)
|
|
model_2.fit(X, y)
|
|
assert model_1.n_iter_ > model_2.n_iter_
|
|
assert model_2.n_iter_ > 3
|
|
|
|
# Strict tolerance and small max_iter should trigger a warning
|
|
model_3 = SGDClassifier(max_iter=3, tol=1e-3, random_state=0)
|
|
warning_message = (
|
|
"Maximum number of iteration reached before "
|
|
"convergence. Consider increasing max_iter to "
|
|
"improve the fit."
|
|
)
|
|
with pytest.warns(ConvergenceWarning, match=warning_message):
|
|
model_3.fit(X, y)
|
|
assert model_3.n_iter_ == 3
|
|
|
|
|
|
def _test_loss_common(loss_function, cases):
|
|
# Test the different loss functions
|
|
# cases is a list of (p, y, expected)
|
|
for p, y, expected_loss, expected_dloss in cases:
|
|
assert_almost_equal(loss_function.py_loss(p, y), expected_loss)
|
|
assert_almost_equal(loss_function.py_dloss(p, y), expected_dloss)
|
|
|
|
|
|
def test_loss_hinge():
|
|
# Test Hinge (hinge / perceptron)
|
|
# hinge
|
|
loss = sgd_fast.Hinge(1.0)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(1.1, 1.0, 0.0, 0.0),
|
|
(-2.0, -1.0, 0.0, 0.0),
|
|
(1.0, 1.0, 0.0, -1.0),
|
|
(-1.0, -1.0, 0.0, 1.0),
|
|
(0.5, 1.0, 0.5, -1.0),
|
|
(2.0, -1.0, 3.0, 1.0),
|
|
(-0.5, -1.0, 0.5, 1.0),
|
|
(0.0, 1.0, 1, -1.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
# perceptron
|
|
loss = sgd_fast.Hinge(0.0)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(1.0, 1.0, 0.0, 0.0),
|
|
(-0.1, -1.0, 0.0, 0.0),
|
|
(0.0, 1.0, 0.0, -1.0),
|
|
(0.0, -1.0, 0.0, 1.0),
|
|
(0.5, -1.0, 0.5, 1.0),
|
|
(2.0, -1.0, 2.0, 1.0),
|
|
(-0.5, 1.0, 0.5, -1.0),
|
|
(-1.0, 1.0, 1.0, -1.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_gradient_squared_hinge():
|
|
# Test SquaredHinge
|
|
loss = sgd_fast.SquaredHinge(1.0)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(1.0, 1.0, 0.0, 0.0),
|
|
(-2.0, -1.0, 0.0, 0.0),
|
|
(1.0, -1.0, 4.0, 4.0),
|
|
(-1.0, 1.0, 4.0, -4.0),
|
|
(0.5, 1.0, 0.25, -1.0),
|
|
(0.5, -1.0, 2.25, 3.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_loss_log():
|
|
# Test Log (logistic loss)
|
|
loss = sgd_fast.Log()
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(1.0, 1.0, np.log(1.0 + np.exp(-1.0)), -1.0 / (np.exp(1.0) + 1.0)),
|
|
(1.0, -1.0, np.log(1.0 + np.exp(1.0)), 1.0 / (np.exp(-1.0) + 1.0)),
|
|
(-1.0, -1.0, np.log(1.0 + np.exp(-1.0)), 1.0 / (np.exp(1.0) + 1.0)),
|
|
(-1.0, 1.0, np.log(1.0 + np.exp(1.0)), -1.0 / (np.exp(-1.0) + 1.0)),
|
|
(0.0, 1.0, np.log(2), -0.5),
|
|
(0.0, -1.0, np.log(2), 0.5),
|
|
(17.9, -1.0, 17.9, 1.0),
|
|
(-17.9, 1.0, 17.9, -1.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
assert_almost_equal(loss.py_dloss(18.1, 1.0), np.exp(-18.1) * -1.0, 16)
|
|
assert_almost_equal(loss.py_loss(18.1, 1.0), np.exp(-18.1), 16)
|
|
assert_almost_equal(loss.py_dloss(-18.1, -1.0), np.exp(-18.1) * 1.0, 16)
|
|
assert_almost_equal(loss.py_loss(-18.1, 1.0), 18.1, 16)
|
|
|
|
|
|
def test_loss_squared_loss():
|
|
# Test SquaredLoss
|
|
loss = sgd_fast.SquaredLoss()
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(0.0, 0.0, 0.0, 0.0),
|
|
(1.0, 1.0, 0.0, 0.0),
|
|
(1.0, 0.0, 0.5, 1.0),
|
|
(0.5, -1.0, 1.125, 1.5),
|
|
(-2.5, 2.0, 10.125, -4.5),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_loss_huber():
|
|
# Test Huber
|
|
loss = sgd_fast.Huber(0.1)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(0.0, 0.0, 0.0, 0.0),
|
|
(0.1, 0.0, 0.005, 0.1),
|
|
(0.0, 0.1, 0.005, -0.1),
|
|
(3.95, 4.0, 0.00125, -0.05),
|
|
(5.0, 2.0, 0.295, 0.1),
|
|
(-1.0, 5.0, 0.595, -0.1),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_loss_modified_huber():
|
|
# (p, y, expected_loss, expected_dloss)
|
|
loss = sgd_fast.ModifiedHuber()
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(1.0, 1.0, 0.0, 0.0),
|
|
(-1.0, -1.0, 0.0, 0.0),
|
|
(2.0, 1.0, 0.0, 0.0),
|
|
(0.0, 1.0, 1.0, -2.0),
|
|
(-1.0, 1.0, 4.0, -4.0),
|
|
(0.5, -1.0, 2.25, 3.0),
|
|
(-2.0, 1.0, 8, -4.0),
|
|
(-3.0, 1.0, 12, -4.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_loss_epsilon_insensitive():
|
|
# Test EpsilonInsensitive
|
|
loss = sgd_fast.EpsilonInsensitive(0.1)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(0.0, 0.0, 0.0, 0.0),
|
|
(0.1, 0.0, 0.0, 0.0),
|
|
(-2.05, -2.0, 0.0, 0.0),
|
|
(3.05, 3.0, 0.0, 0.0),
|
|
(2.2, 2.0, 0.1, 1.0),
|
|
(2.0, -1.0, 2.9, 1.0),
|
|
(2.0, 2.2, 0.1, -1.0),
|
|
(-2.0, 1.0, 2.9, -1.0),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_loss_squared_epsilon_insensitive():
|
|
# Test SquaredEpsilonInsensitive
|
|
loss = sgd_fast.SquaredEpsilonInsensitive(0.1)
|
|
cases = [
|
|
# (p, y, expected_loss, expected_dloss)
|
|
(0.0, 0.0, 0.0, 0.0),
|
|
(0.1, 0.0, 0.0, 0.0),
|
|
(-2.05, -2.0, 0.0, 0.0),
|
|
(3.05, 3.0, 0.0, 0.0),
|
|
(2.2, 2.0, 0.01, 0.2),
|
|
(2.0, -1.0, 8.41, 5.8),
|
|
(2.0, 2.2, 0.01, -0.2),
|
|
(-2.0, 1.0, 8.41, -5.8),
|
|
]
|
|
_test_loss_common(loss, cases)
|
|
|
|
|
|
def test_multi_thread_multi_class_and_early_stopping():
|
|
# This is a non-regression test for a bad interaction between
|
|
# early stopping internal attribute and thread-based parallelism.
|
|
clf = SGDClassifier(
|
|
alpha=1e-3,
|
|
tol=1e-3,
|
|
max_iter=1000,
|
|
early_stopping=True,
|
|
n_iter_no_change=100,
|
|
random_state=0,
|
|
n_jobs=2,
|
|
)
|
|
clf.fit(iris.data, iris.target)
|
|
assert clf.n_iter_ > clf.n_iter_no_change
|
|
assert clf.n_iter_ < clf.n_iter_no_change + 20
|
|
assert clf.score(iris.data, iris.target) > 0.8
|
|
|
|
|
|
def test_multi_core_gridsearch_and_early_stopping():
|
|
# This is a non-regression test for a bad interaction between
|
|
# early stopping internal attribute and process-based multi-core
|
|
# parallelism.
|
|
param_grid = {
|
|
"alpha": np.logspace(-4, 4, 9),
|
|
"n_iter_no_change": [5, 10, 50],
|
|
}
|
|
|
|
clf = SGDClassifier(tol=1e-2, max_iter=1000, early_stopping=True, random_state=0)
|
|
search = RandomizedSearchCV(clf, param_grid, n_iter=5, n_jobs=2, random_state=0)
|
|
search.fit(iris.data, iris.target)
|
|
assert search.best_score_ > 0.8
|
|
|
|
|
|
@pytest.mark.parametrize("backend", ["loky", "multiprocessing", "threading"])
|
|
def test_SGDClassifier_fit_for_all_backends(backend):
|
|
# This is a non-regression smoke test. In the multi-class case,
|
|
# SGDClassifier.fit fits each class in a one-versus-all fashion using
|
|
# joblib.Parallel. However, each OvA step updates the coef_ attribute of
|
|
# the estimator in-place. Internally, SGDClassifier calls Parallel using
|
|
# require='sharedmem'. This test makes sure SGDClassifier.fit works
|
|
# consistently even when the user asks for a backend that does not provide
|
|
# sharedmem semantics.
|
|
|
|
# We further test a case where memmapping would have been used if
|
|
# SGDClassifier.fit was called from a loky or multiprocessing backend. In
|
|
# this specific case, in-place modification of clf.coef_ would have caused
|
|
# a segmentation fault when trying to write in a readonly memory mapped
|
|
# buffer.
|
|
|
|
random_state = np.random.RandomState(42)
|
|
|
|
# Create a classification problem with 50000 features and 20 classes. Using
|
|
# loky or multiprocessing this make the clf.coef_ exceed the threshold
|
|
# above which memmaping is used in joblib and loky (1MB as of 2018/11/1).
|
|
X = sp.random(500, 2000, density=0.02, format="csr", random_state=random_state)
|
|
y = random_state.choice(20, 500)
|
|
|
|
# Begin by fitting a SGD classifier sequentially
|
|
clf_sequential = SGDClassifier(max_iter=1000, n_jobs=1, random_state=42)
|
|
clf_sequential.fit(X, y)
|
|
|
|
# Fit a SGDClassifier using the specified backend, and make sure the
|
|
# coefficients are equal to those obtained using a sequential fit
|
|
clf_parallel = SGDClassifier(max_iter=1000, n_jobs=4, random_state=42)
|
|
with joblib.parallel_backend(backend=backend):
|
|
clf_parallel.fit(X, y)
|
|
assert_array_almost_equal(clf_sequential.coef_, clf_parallel.coef_)
|
|
|
|
|
|
# TODO(1.3): Remove
|
|
@pytest.mark.parametrize(
|
|
"old_loss, new_loss, Estimator",
|
|
[
|
|
("log", "log_loss", linear_model.SGDClassifier),
|
|
],
|
|
)
|
|
def test_loss_deprecated(old_loss, new_loss, Estimator):
|
|
|
|
# Note: class BaseSGD calls self._validate_params() in __init__, therefore
|
|
# even instantiation of class raises FutureWarning for deprecated losses.
|
|
with pytest.warns(FutureWarning, match=f"The loss '{old_loss}' was deprecated"):
|
|
est1 = Estimator(loss=old_loss, random_state=0)
|
|
est1.fit(X, Y)
|
|
|
|
est2 = Estimator(loss=new_loss, random_state=0)
|
|
est2.fit(X, Y)
|
|
if hasattr(est1, "predict_proba"):
|
|
assert_allclose(est1.predict_proba(X), est2.predict_proba(X))
|
|
else:
|
|
assert_allclose(est1.predict(X), est2.predict(X))
|
|
|
|
|
|
@pytest.mark.parametrize(
|
|
"Estimator", [linear_model.SGDClassifier, linear_model.SGDRegressor]
|
|
)
|
|
def test_sgd_random_state(Estimator, global_random_seed):
|
|
# Train the same model on the same data without converging and check that we
|
|
# get reproducible results by fixing the random seed.
|
|
if Estimator == linear_model.SGDRegressor:
|
|
X, y = datasets.make_regression(random_state=global_random_seed)
|
|
else:
|
|
X, y = datasets.make_classification(random_state=global_random_seed)
|
|
|
|
# Fitting twice a model with the same hyper-parameters on the same training
|
|
# set with the same seed leads to the same results deterministically.
|
|
|
|
est = Estimator(random_state=global_random_seed, max_iter=1)
|
|
with pytest.warns(ConvergenceWarning):
|
|
coef_same_seed_a = est.fit(X, y).coef_
|
|
assert est.n_iter_ == 1
|
|
|
|
est = Estimator(random_state=global_random_seed, max_iter=1)
|
|
with pytest.warns(ConvergenceWarning):
|
|
coef_same_seed_b = est.fit(X, y).coef_
|
|
assert est.n_iter_ == 1
|
|
|
|
assert_allclose(coef_same_seed_a, coef_same_seed_b)
|
|
|
|
# Fitting twice a model with the same hyper-parameters on the same training
|
|
# set but with different random seed leads to different results after one
|
|
# epoch because of the random shuffling of the dataset.
|
|
|
|
est = Estimator(random_state=global_random_seed + 1, max_iter=1)
|
|
with pytest.warns(ConvergenceWarning):
|
|
coef_other_seed = est.fit(X, y).coef_
|
|
assert est.n_iter_ == 1
|
|
|
|
assert np.abs(coef_same_seed_a - coef_other_seed).max() > 1.0
|
|
|
|
|
|
def test_validation_mask_correctly_subsets(monkeypatch):
|
|
"""Test that data passed to validation callback correctly subsets.
|
|
|
|
Non-regression test for #23255.
|
|
"""
|
|
X, Y = iris.data, iris.target
|
|
n_samples = X.shape[0]
|
|
validation_fraction = 0.2
|
|
clf = linear_model.SGDClassifier(
|
|
early_stopping=True,
|
|
tol=1e-3,
|
|
max_iter=1000,
|
|
validation_fraction=validation_fraction,
|
|
)
|
|
|
|
mock = Mock(side_effect=_stochastic_gradient._ValidationScoreCallback)
|
|
monkeypatch.setattr(_stochastic_gradient, "_ValidationScoreCallback", mock)
|
|
clf.fit(X, Y)
|
|
|
|
X_val, y_val = mock.call_args[0][1:3]
|
|
assert X_val.shape[0] == int(n_samples * validation_fraction)
|
|
assert y_val.shape[0] == int(n_samples * validation_fraction)
|
|
|
|
|
|
def test_sgd_error_on_zero_validation_weight():
|
|
# Test that SGDClassifier raises error when all the validation samples
|
|
# have zero sample_weight. Non-regression test for #17229.
|
|
X, Y = iris.data, iris.target
|
|
sample_weight = np.zeros_like(Y)
|
|
validation_fraction = 0.4
|
|
|
|
clf = linear_model.SGDClassifier(
|
|
early_stopping=True, validation_fraction=validation_fraction, random_state=0
|
|
)
|
|
|
|
error_message = (
|
|
"The sample weights for validation set are all zero, consider using a"
|
|
" different random state."
|
|
)
|
|
with pytest.raises(ValueError, match=error_message):
|
|
clf.fit(X, Y, sample_weight=sample_weight)
|
|
|
|
|
|
@pytest.mark.parametrize("Estimator", [SGDClassifier, SGDRegressor])
|
|
def test_sgd_verbose(Estimator):
|
|
"""non-regression test for gh #25249"""
|
|
Estimator(verbose=1).fit(X, Y)
|