Example #1
0
def test_ransac_none_estimator():

    base_estimator = LinearRegression()

    ransac_estimator = RANSACRegressor(base_estimator,
                                       min_samples=2,
                                       residual_threshold=5,
                                       random_state=0)
    ransac_none_estimator = RANSACRegressor(None, 2, 5, random_state=0)

    ransac_estimator.fit(X, y)
    ransac_none_estimator.fit(X, y)

    assert_array_almost_equal(ransac_estimator.predict(X),
                              ransac_none_estimator.predict(X))
Example #2
0
def test_ransac_predict():
    X = np.arange(100)[:, None]
    y = np.zeros((100, ))
    y[0] = 1
    y[1] = 100

    base_estimator = LinearRegression()
    ransac_estimator = RANSACRegressor(base_estimator,
                                       min_samples=2,
                                       residual_threshold=0.5,
                                       random_state=0)
    ransac_estimator.fit(X, y)

    assert_array_equal(ransac_estimator.predict(X), np.zeros(100))
Example #3
0
def test_ransac_residual_loss():
    loss_multi1 = lambda y_true, y_pred: np.sum(np.abs(y_true - y_pred),
                                                axis=1)
    loss_multi2 = lambda y_true, y_pred: np.sum((y_true - y_pred)**2, axis=1)

    loss_mono = lambda y_true, y_pred: np.abs(y_true - y_pred)
    yyy = np.column_stack([y, y, y])

    base_estimator = LinearRegression()
    ransac_estimator0 = RANSACRegressor(base_estimator,
                                        min_samples=2,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator1 = RANSACRegressor(base_estimator,
                                        min_samples=2,
                                        residual_threshold=5,
                                        random_state=0,
                                        loss=loss_multi1)
    ransac_estimator2 = RANSACRegressor(base_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(base_estimator,
                                        min_samples=2,
                                        residual_threshold=5,
                                        random_state=0,
                                        loss="squared_loss")
    ransac_estimator3.fit(X, y)
    assert_array_almost_equal(ransac_estimator0.predict(X),
                              ransac_estimator2.predict(X))
Example #4
0
def test_ransac_min_n_samples():
    base_estimator = LinearRegression()
    ransac_estimator1 = RANSACRegressor(base_estimator,
                                        min_samples=2,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator2 = RANSACRegressor(base_estimator,
                                        min_samples=2. / X.shape[0],
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator3 = RANSACRegressor(base_estimator,
                                        min_samples=-1,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator4 = RANSACRegressor(base_estimator,
                                        min_samples=5.2,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator5 = RANSACRegressor(base_estimator,
                                        min_samples=2.0,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator6 = RANSACRegressor(base_estimator,
                                        residual_threshold=5,
                                        random_state=0)
    ransac_estimator7 = RANSACRegressor(base_estimator,
                                        min_samples=X.shape[0] + 1,
                                        residual_threshold=5,
                                        random_state=0)

    ransac_estimator1.fit(X, y)
    ransac_estimator2.fit(X, y)
    ransac_estimator5.fit(X, y)
    ransac_estimator6.fit(X, y)

    assert_array_almost_equal(ransac_estimator1.predict(X),
                              ransac_estimator2.predict(X))
    assert_array_almost_equal(ransac_estimator1.predict(X),
                              ransac_estimator5.predict(X))
    assert_array_almost_equal(ransac_estimator1.predict(X),
                              ransac_estimator6.predict(X))

    assert_raises(ValueError, ransac_estimator3.fit, X, y)
    assert_raises(ValueError, ransac_estimator4.fit, X, y)
    assert_raises(ValueError, ransac_estimator7.fit, X, y)