def test_regressor_mse():
    y_bin = y.copy()
    y_bin[y != 1] = -1

    for data in (X, X_csr):
        for fit_intercept in (True, False):
            reg = PassiveAggressiveRegressor(C=1.0, n_iter=50,
                                             fit_intercept=fit_intercept,
                                             random_state=0)
            reg.fit(data, y_bin)
            pred = reg.predict(data)
            assert_less(np.mean((y_bin - pred) ** 2), 1.7)
dataset/ETHPy150Open scikit-learn/scikit-learn/sklearn/linear_model/tests/test_passive_aggressive.py/test_regressor_mse/swapped operands of `-`