def test_fast_predict():
# test that the faster prediction change doesn't
# affect out-of-sample predictions:
# https://github.com/scikit-learn/scikit-learn/pull/6206
rng = np.random.RandomState(123)
n_samples = 10**3
# X values over the -10,10 range
X_train = 20.0 * rng.rand(n_samples) - 10
y_train = np.less(rng.rand(n_samples),
expit(X_train)).astype('int64').astype('float64')
weights = rng.rand(n_samples)
# we also want to test that everything still works when some weights are 0
weights[rng.rand(n_samples) < 0.1] = 0
slow_model = IsotonicRegression(y_min=0, y_max=1, out_of_bounds="clip")
fast_model = IsotonicRegression(y_min=0, y_max=1, out_of_bounds="clip")
# Build interpolation function with ALL input data, not just the
# non-redundant subset. The following 2 lines are taken from the
# .fit() method, without removing unnecessary points
X_train_fit, y_train_fit = slow_model._build_y(X_train,
y_train,
sample_weight=weights,
trim_duplicates=False)
slow_model._build_f(X_train_fit, y_train_fit)
# fit with just the necessary data
fast_model.fit(X_train, y_train, sample_weight=weights)
X_test = 20.0 * rng.rand(n_samples) - 10
y_pred_slow = slow_model.predict(X_test)
y_pred_fast = fast_model.predict(X_test)
assert_array_equal(y_pred_slow, y_pred_fast)
def test_isotonic_regression_oob_clip():
# Set y and x
y = np.array([3, 7, 5, 9, 8, 7, 10])
x = np.arange(len(y))
# Create model and fit
ir = IsotonicRegression(increasing='auto', out_of_bounds="clip")
ir.fit(x, y)
# Predict from training and test x and check that min/max match.
y1 = ir.predict([min(x) - 10, max(x) + 10])
y2 = ir.predict(x)
assert max(y1) == max(y2)
assert min(y1) == min(y2)
def test_isotonic_regression():
y = np.array([3, 7, 5, 9, 8, 7, 10])
y_ = np.array([3, 6, 6, 8, 8, 8, 10])
assert_array_equal(y_, isotonic_regression(y))
y = np.array([10, 0, 2])
y_ = np.array([4, 4, 4])
assert_array_equal(y_, isotonic_regression(y))
x = np.arange(len(y))
ir = IsotonicRegression(y_min=0., y_max=1.)
ir.fit(x, y)
assert_array_equal(ir.fit(x, y).transform(x), ir.fit_transform(x, y))
assert_array_equal(ir.transform(x), ir.predict(x))
# check that it is immune to permutation
perm = np.random.permutation(len(y))
ir = IsotonicRegression(y_min=0., y_max=1.)
assert_array_equal(ir.fit_transform(x[perm], y[perm]),
ir.fit_transform(x, y)[perm])
assert_array_equal(ir.transform(x[perm]), ir.transform(x)[perm])
# check we don't crash when all x are equal:
ir = IsotonicRegression()
assert_array_equal(ir.fit_transform(np.ones(len(x)), y), np.mean(y))
def test_isotonic_mismatched_dtype(y_dtype):
# regression test for #15004
# check that data are converted when X and y dtype differ
reg = IsotonicRegression()
y = np.array([2, 1, 4, 3, 5], dtype=y_dtype)
X = np.arange(len(y), dtype=np.float32)
reg.fit(X, y)
assert reg.predict(X).dtype == X.dtype
def test_isotonic_duplicate_min_entry():
x = [0, 0, 1]
y = [0, 0, 1]
ir = IsotonicRegression(increasing=True, out_of_bounds="clip")
ir.fit(x, y)
all_predictions_finite = np.all(np.isfinite(ir.predict(x)))
assert all_predictions_finite
def test_isotonic_regression_pickle():
y = np.array([3, 7, 5, 9, 8, 7, 10])
x = np.arange(len(y))
# Create model and fit
ir = IsotonicRegression(increasing='auto', out_of_bounds="clip")
ir.fit(x, y)
ir_ser = pickle.dumps(ir, pickle.HIGHEST_PROTOCOL)
ir2 = pickle.loads(ir_ser)
np.testing.assert_array_equal(ir.predict(x), ir2.predict(x))
def test_isotonic_regression_oob_nan():
# Set y and x
y = np.array([3, 7, 5, 9, 8, 7, 10])
x = np.arange(len(y))
# Create model and fit
ir = IsotonicRegression(increasing='auto', out_of_bounds="nan")
ir.fit(x, y)
# Predict from training and test x and check that we have two NaNs.
y1 = ir.predict([min(x) - 10, max(x) + 10])
assert sum(np.isnan(y1)) == 2
def test_isotonic_dtype():
y = [2, 1, 4, 3, 5]
weights = np.array([.9, .9, .9, .9, .9], dtype=np.float64)
reg = IsotonicRegression()
for dtype in (np.int32, np.int64, np.float32, np.float64):
for sample_weight in (None, weights.astype(np.float32), weights):
y_np = np.array(y, dtype=dtype)
expected_dtype = \
check_array(y_np, dtype=[np.float64, np.float32],
ensure_2d=False).dtype
res = isotonic_regression(y_np, sample_weight=sample_weight)
assert res.dtype == expected_dtype
X = np.arange(len(y)).astype(dtype)
reg.fit(X, y_np, sample_weight=sample_weight)
res = reg.predict(X)
assert res.dtype == expected_dtype