def test_polynomial_detrending():
import numpy as np
import pandas as pd
from sktime.forecasting.tests.test_trend import get_expected_polynomial_coefs
from sktime.forecasting.trend import PolynomialTrendForecaster
from sktime.transformations.series.detrend import Detrender
y = pd.Series(np.arange(20) * 0.5) + np.random.normal(0, 1, size=20)
forecaster = PolynomialTrendForecaster(degree=1, with_intercept=True)
transformer = Detrender(forecaster)
transformer.fit(y)
# check coefficients
actual_coefs = transformer.forecaster_.regressor_.steps[-1][-1].coef_
expected_coefs = get_expected_polynomial_coefs(y,
degree=1,
with_intercept=True)[::-1]
np.testing.assert_array_almost_equal(actual_coefs, expected_coefs)
# check trend
expected_trend = expected_coefs[0] + np.arange(len(y)) * expected_coefs[1]
actual_trend = transformer.forecaster_.predict(-np.arange(len(y)))
np.testing.assert_array_almost_equal(actual_trend, expected_trend)
# check residuals
actual = transformer.transform(y)
expected = y - expected_trend
np.testing.assert_array_almost_equal(actual, expected)
def compute_expected_y_pred(y_train, fh):
# fitting
yt = y_train.copy()
t1 = Deseasonalizer(sp=12, model="multiplicative")
yt = t1.fit_transform(yt)
t2 = Detrender(PolynomialTrendForecaster(degree=1))
yt = t2.fit_transform(yt)
forecaster = NaiveForecaster()
forecaster.fit(yt, fh=fh)
# predicting
y_pred = forecaster.predict()
y_pred = t2.inverse_transform(y_pred)
y_pred = t1.inverse_transform(y_pred)
return y_pred
def test_pipeline():
y = load_airline()
y_train, y_test = temporal_train_test_split(y)
forecaster = TransformedTargetForecaster([
("t1", Deseasonalizer(sp=12, model="multiplicative")),
("t2", Detrender(PolynomialTrendForecaster(degree=1))),
("forecaster", NaiveForecaster()),
])
fh = np.arange(len(y_test)) + 1
forecaster.fit(y_train, fh=fh)
actual = forecaster.predict()
def compute_expected_y_pred(y_train, fh):
# fitting
yt = y_train.copy()
t1 = Deseasonalizer(sp=12, model="multiplicative")
yt = t1.fit_transform(yt)
t2 = Detrender(PolynomialTrendForecaster(degree=1))
yt = t2.fit_transform(yt)
forecaster = NaiveForecaster()
forecaster.fit(yt, fh=fh)
# predicting
y_pred = forecaster.predict()
y_pred = t2.inverse_transform(y_pred)
y_pred = t1.inverse_transform(y_pred)
return y_pred
expected = compute_expected_y_pred(y_train, fh)
np.testing.assert_array_equal(actual, expected)
def get_test_params(cls):
"""Return testing parameter settings for the estimator.
Returns
-------
params : dict or list of dict, default = {}
Parameters to create testing instances of the class
Each dict are parameters to construct an "interesting" test instance, i.e.,
`MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
`create_test_instance` uses the first (or only) dictionary in `params`
"""
from sktime.transformations.series.detrend import Detrender
return {"transformer": Detrender()}
def get_test_params(cls, parameter_set="default"):
"""Return testing parameter settings for the estimator.
Parameters
----------
parameter_set : str, default="default"
Name of the set of test parameters to return, for use in tests. If no
special parameters are defined for a value, will return `"default"` set.
Returns
-------
params : dict or list of dict, default = {}
Parameters to create testing instances of the class
Each dict are parameters to construct an "interesting" test instance, i.e.,
`MyClass(**params)` or `MyClass(**params[i])` creates a valid test instance.
`create_test_instance` uses the first (or only) dictionary in `params`
"""
from sktime.transformations.series.detrend import Detrender
return {"transformer": Detrender()}
def test_nesting_pipelines():
"""Test that nesting of pipelines works."""
from sktime.forecasting.ets import AutoETS
from sktime.transformations.series.boxcox import LogTransformer
from sktime.transformations.series.compose import OptionalPassthrough
from sktime.transformations.series.detrend import Detrender
from sktime.utils._testing.scenarios_forecasting import (
ForecasterFitPredictUnivariateWithX, )
pipe = ForecastingPipeline(steps=[
("logX", OptionalPassthrough(LogTransformer())),
("detrenderX", OptionalPassthrough(Detrender(forecaster=AutoETS()))),
(
"etsforecaster",
TransformedTargetForecaster(steps=[
("log", OptionalPassthrough(LogTransformer())),
("autoETS", AutoETS()),
]),
),
])
scenario = ForecasterFitPredictUnivariateWithX()
scenario.run(pipe, method_sequence=["fit", "predict"])
(
"transformer2",
SeriesToSeriesRowTransformer(SERIES_TO_SERIES_TRANSFORMER,
check_transformer=False),
),
]
REGRESSOR = LinearRegression()
TIME_SERIES_CLASSIFIER = TimeSeriesForest(n_estimators=3)
TIME_SERIES_CLASSIFIERS = [
("tsf1", TIME_SERIES_CLASSIFIER),
("tsf2", TIME_SERIES_CLASSIFIER),
]
FORECASTER = ExponentialSmoothing()
FORECASTERS = [("ses1", FORECASTER), ("ses2", FORECASTER)]
STEPS = [
("transformer", Detrender(ThetaForecaster())),
("forecaster", NaiveForecaster()),
]
ESTIMATOR_TEST_PARAMS = {
OnlineEnsembleForecaster: {
"forecasters": FORECASTERS
},
FeatureUnion: {
"transformer_list": TRANSFORMERS
},
DirectRegressionForecaster: {
"regressor": REGRESSOR
},
MultioutputRegressionForecaster: {
"regressor": REGRESSOR
},
best_idx = gscv.best_index_
assert best_idx == actual.argmin()
best_params = gscv.best_params_
assert best_params == param_grid[best_idx]
# Check if best parameters are contained in best forecaster.
best_forecaster_params = gscv.best_forecaster_.get_params()
best_params = gscv.best_params_
assert best_params.items() <= best_forecaster_params.items()
NAIVE = NaiveForecaster(strategy="mean")
NAIVE_GRID = {"window_length": TEST_WINDOW_LENGTHS}
PIPE = TransformedTargetForecaster([
("transformer", Detrender(PolynomialTrendForecaster())),
("forecaster", ARIMA()),
])
PIPE_GRID = {
"transformer__forecaster__degree": [1, 2],
"forecaster__with_intercept": [True, False],
}
CVs = [
*[SingleWindowSplitter(fh=fh) for fh in TEST_OOS_FHS],
SlidingWindowSplitter(fh=1, initial_window=15),
]
@pytest.mark.parametrize("forecaster, param_grid", [(NAIVE, NAIVE_GRID),
(PIPE, PIPE_GRID)])
@pytest.mark.parametrize("scoring", TEST_METRICS)
},
Imputer: {
"method": "mean"
},
HampelFilter: {
"window_length": 3
},
OptionalPassthrough: {
"transformer": BoxCoxTransformer(),
"passthrough": False
},
FeatureSelection: {
"method": "all"
},
ColumnwiseTransformer: {
"transformer": Detrender()
},
AggrDist: {
"transformer": ScipyDist()
},
PyODAnnotator: {
"estimator": ANOMALY_DETECTOR
},
ClaSPSegmentation: {
"period_length": 5,
"n_cps": 1
},
ClaSPTransformer: {
"window_length": 5
},
}
y_test_subset = y_test.loc[
y_pred.index
] # select only time points which we predicted
scores[i] = scoring(y_test_subset, y_pred)
return scores
@pytest.mark.parametrize(
"forecaster, param_dict",
[
(NaiveForecaster(strategy="mean"), {"window_length": TEST_WINDOW_LENGTHS}),
# atomic estimator
(
TransformedTargetForecaster(
[ # composite estimator
("t", Detrender(PolynomialTrendForecaster())),
("f", ReducedForecaster(LinearRegression(), scitype="regressor")),
]
),
{
"f__window_length": TEST_WINDOW_LENGTHS,
"f__step_length": TEST_STEP_LENGTHS,
},
), # multiple params
],
)
@pytest.mark.parametrize(
"scoring",
[sMAPE(), make_forecasting_scorer(mean_squared_error, greater_is_better=False)],
)
@pytest.mark.parametrize(
SeriesToSeriesRowTransformer(
SERIES_TO_SERIES_TRANSFORMER, check_transformer=False
),
),
]
REGRESSOR = LinearRegression()
ANOMALY_DETECTOR = KNN()
TIME_SERIES_CLASSIFIER = TSFC(n_estimators=3)
TIME_SERIES_CLASSIFIERS = [
("tsf1", TIME_SERIES_CLASSIFIER),
("tsf2", TIME_SERIES_CLASSIFIER),
]
FORECASTER = ExponentialSmoothing()
FORECASTERS = [("ses1", FORECASTER), ("ses2", FORECASTER)]
STEPS_y = [
("transformer", Detrender(ThetaForecaster())),
("forecaster", NaiveForecaster()),
]
STEPS_X = [
("transformer", TabularToSeriesAdaptor(StandardScaler())),
("forecaster", NaiveForecaster()),
]
ESTIMATOR_TEST_PARAMS = {
ColumnEnsembleForecaster: {"forecasters": FORECASTER},
OnlineEnsembleForecaster: {"forecasters": FORECASTERS},
FeatureUnion: {"transformer_list": TRANSFORMERS},
DirectTabularRegressionForecaster: {"estimator": REGRESSOR},
MultioutputTabularRegressionForecaster: {"estimator": REGRESSOR},
RecursiveTabularRegressionForecaster: {"estimator": REGRESSOR},
DirRecTabularRegressionForecaster: {"estimator": REGRESSOR},
DirectTimeSeriesRegressionForecaster: {