def fit(self, y, X=None, fh=None):
"""Fit to training data.
Parameters
----------
y : pd.Series
Target time series to which to fit the forecaster.
X : pd.DataFrame, optional (default=None)
Exogenous variables are ignored
fh : int, list or np.array, optional (default=None)
The forecasters horizon with the steps ahead to to predict.
Returns
-------
self : returns an instance of self.
"""
n_timepoints = len(y)
self._set_y_X(y, X)
self._set_fh(fh)
self.step_length_ = check_step_length(self.step_length)
self.window_length_ = check_window_length(self.window_length,
n_timepoints)
self._fit(y, X)
self._is_fitted = True
return self
def get_cutoffs(self, y: Optional[ACCEPTED_Y_TYPES] = None) -> np.ndarray:
"""Return the cutoff points.
Parameters
----------
y : pd.Series or pd.Index, optional (default=None)
Time series to split
Returns
-------
cutoffs : np.array
The array of cutoff points.
"""
if y is None:
raise ValueError(
f"{self.__class__.__name__} requires `y` to compute the cutoffs."
)
y = _check_y(y)
fh = _check_fh(self.fh)
step_length = check_step_length(self.step_length)
if hasattr(self, "initial_window") and self.initial_window is not None:
if is_timedelta_or_date_offset(x=self.initial_window):
start = y.get_loc(y[0] + self.initial_window)
else:
start = self.initial_window
else:
start = self._get_start(y=y, fh=fh)
end = _get_end(y, fh)
step_length = self._get_step_length(x=step_length)
return np.arange(start, end, step_length) - 1
def get_cutoffs(self, y=None):
"""Get the cutoff time points.
Parameters
----------
y : pd.Series or pd.Index, optional (default=None)
Returns
-------
cutoffs : np.array
"""
if y is None:
raise ValueError(
f"{self.__class__.__name__} requires `y` to compute the cutoffs."
)
y = _check_y(y)
fh = _check_fh(self.fh)
step_length = check_step_length(self.step_length)
if hasattr(self, "initial_window") and self.initial_window is not None:
start = self.initial_window
else:
start = self._get_start(fh)
end = _get_end(y, fh)
return np.arange(start, end, step_length) - 1
def _split(self, y):
step_length = check_step_length(self.step_length)
window_length = check_window_length(self.window_length, "window_length")
initial_window = check_window_length(self.initial_window, "initial_window")
fh = _check_fh(self.fh)
_check_window_lengths(y, fh, window_length, initial_window)
if self.initial_window is not None:
if not self.start_with_window:
raise ValueError(
"`start_with_window` must be True if `initial_window` is given"
)
if self.initial_window <= self.window_length:
raise ValueError("`initial_window` must greater than `window_length`")
# For in-sample forecasting horizons, the first split must ensure that
# in-sample test set is still within the data.
if not fh.is_all_out_of_sample() and abs(fh[0]) >= self.initial_window:
initial_start = abs(fh[0]) - self.initial_window + 1
else:
initial_start = 0
initial_end = initial_start + initial_window
train = np.arange(initial_start, initial_end)
test = initial_end + fh.to_numpy() - 1
yield train, test
start = self._get_start(fh)
end = _get_end(y, fh)
for train, test in self._split_windows(
start, end, step_length, window_length, fh.to_numpy()
):
yield train, test
def _split(self, y: pd.Index) -> SPLIT_GENERATOR_TYPE:
n_timepoints = y.shape[0]
step_length = check_step_length(self.step_length)
window_length = check_window_length(
window_length=self.window_length,
n_timepoints=n_timepoints,
name="window_length",
)
initial_window = check_window_length(
window_length=self.initial_window,
n_timepoints=n_timepoints,
name="initial_window",
)
fh = _check_fh(self.fh)
_check_window_lengths(
y=y, fh=fh, window_length=window_length, initial_window=initial_window
)
if self.initial_window is not None:
yield self._split_for_initial_window(y)
start = self._get_start(y=y, fh=fh)
end = _get_end(y_index=y, fh=fh) + 2
step_length = self._get_step_length(x=step_length)
for train, test in self._split_windows(
start=start,
end=end,
step_length=step_length,
window_length=window_length,
y=y,
fh=fh.to_numpy(),
):
yield train, test
def _split_windows(self, y):
step_length = check_step_length(self.step_length)
window_length = check_window_length(self.window_length)
fh = self._check_fh()
end = self._get_end(y)
start = self._get_start()
for split_point in range(start, end, step_length):
training_window = np.arange(split_point - window_length, split_point)
test_window = split_point + fh - 1
yield training_window, test_window
def fit(self, y, X=None, fh=None):
"""Fit to training data.
Parameters
----------
y : pd.Series
Target time series to which to fit the forecaster.
fh : int, list or np.array, optional (default=None)
The forecasters horizon with the steps ahead to to predict.
X : pd.DataFrame, optional (default=None)
Exogenous variables are ignored
Returns
-------
self : returns an instance of self.
"""
self._set_y_X(y, X)
if X is not None:
raise NotImplementedError(
"Exogenous variables `X` are not yet supported.")
self._set_fh(fh)
if len(self.fh.to_in_sample(self.cutoff)) > 0:
raise NotImplementedError(
"In-sample predictions are not implemented")
self.step_length_ = check_step_length(self.step_length)
self.window_length_ = check_window_length(self.window_length)
# for the direct reduction strategy, a separate forecaster is fitted
# for each step ahead of the forecasting horizon
self._cv = SlidingWindowSplitter(
fh=self.fh.to_relative(self.cutoff),
window_length=self.window_length_,
step_length=self.step_length_,
start_with_window=True,
)
# transform data using rolling window split
X, Y_train = self._transform(y, X)
# iterate over forecasting horizon
self.regressors_ = []
for i in range(len(self.fh)):
y = Y_train[:, i]
regressor = clone(self.regressor)
regressor.fit(X, y)
self.regressors_.append(regressor)
self._is_fitted = True
return self
def _split(self, y: Optional[ACCEPTED_Y_TYPES]) -> SPLIT_GENERATOR_TYPE:
n_timepoints = y.shape[0]
step_length = check_step_length(self.step_length)
window_length = check_window_length(self.window_length, n_timepoints,
"window_length")
initial_window = check_window_length(self.initial_window, n_timepoints,
"initial_window")
fh = _check_fh(self.fh)
_check_window_lengths(y, fh, window_length, initial_window)
if self.initial_window is not None:
if not self.start_with_window:
raise ValueError(
"`start_with_window` must be True if `initial_window` is given"
)
if self.initial_window <= self.window_length:
raise ValueError(
"`initial_window` must greater than `window_length`")
if is_timedelta_or_date_offset(x=self.initial_window):
initial_window_threshold = y.get_loc(y[0] +
self.initial_window)
else:
initial_window_threshold = self.initial_window
# For in-sample forecasting horizons, the first split must ensure that
# in-sample test set is still within the data.
if not fh.is_all_out_of_sample() and abs(
fh[0]) >= initial_window_threshold:
initial_start = abs(fh[0]) - self.initial_window + 1
else:
initial_start = 0
if is_timedelta_or_date_offset(x=initial_window):
initial_end = y.get_loc(y[initial_start] + initial_window)
else:
initial_end = initial_start + initial_window
train = np.arange(initial_start, initial_end)
test = initial_end + fh.to_numpy() - 1
yield train, test
start = self._get_start(y=y, fh=fh)
end = _get_end(y=y, fh=fh)
step_length = self._get_step_length(x=step_length)
for train, test in self._split_windows(start, end,
step_length, window_length, y,
fh.to_numpy()):
yield train, test
def fit(self, y_train, fh=None, X_train=None):
"""Fit to training data.
Parameters
----------
y_train : pd.Series
Target time series to which to fit the forecaster.
fh : int, list or np.array, optional (default=None)
The forecasters horizon with the steps ahead to to predict.
X_train : pd.DataFrame, optional (default=None)
Exogenous variables are ignored
Returns
-------
self : returns an instance of self.
"""
# input checks
if X_train is not None:
raise NotImplementedError()
self._set_oh(y_train)
self._set_fh(fh)
if np.any(self.fh <= 0):
raise NotImplementedError(
"in-sample predictions are not implemented")
self.step_length_ = check_step_length(self.step_length)
self.window_length_ = check_window_length(self.window_length)
# for the direct reduction strategy, a separate forecaster is fitted
# for each step ahead of the forecasting horizon
self._cv = SlidingWindowSplitter(fh=self.fh,
window_length=self.window_length_,
step_length=self.step_length_,
start_with_window=True)
# transform data using rolling window split
X_train, Y_train = self._transform(y_train, X_train)
# iterate over forecasting horizon
self.regressors_ = []
for i in range(len(self.fh)):
y_train = Y_train[:, i]
regressor = clone(self.regressor)
regressor.fit(X_train, y_train)
self.regressors_.append(regressor)
self._is_fitted = True
return self
def fit(self, y_train, fh=None, X_train=None):
"""Fit to training data.
Parameters
----------
y_train : pd.Series
Target time series to which to fit the forecaster.
fh : int, list or np.array, optional (default=None)
The forecasters horizon with the steps ahead to to predict.
X_train : pd.DataFrame, optional (default=None)
Exogenous variables are ignored
Returns
-------
self : returns an instance of self.
"""
# input checks
if X_train is not None:
raise NotImplementedError()
# set values
self._set_y_X(y_train, X_train)
self._set_fh(fh)
# Set this and then call the super method, that should be enought I think .....
self._nbr_dependent = y_train.shape[1]
self.step_length_ = check_step_length(self.step_length)
self.window_length_ = check_window_length(self.window_length)
# set up cv iterator, for recursive strategy, a single estimator
# is fit for a one-step-ahead forecasting horizon and then called
# iteratively to predict multiple steps ahead
self._cv = SlidingWindowSplitter(
fh=1,
window_length=self.window_length_,
step_length=self.step_length_,
start_with_window=True,
)
# transform data into tabular form
X_train_tab, y_train_tab = self._transform(y_train, X_train)
# fit base regressor
regressor = clone(self.regressor)
regressor.fit(X_train_tab, y_train_tab)
self.regressor_ = regressor
self._is_fitted = True
return self
def fit(self, y, X=None, fh=None):
"""Fit to training data.
Parameters
----------
y : pd.Series
Target time series to which to fit the forecaster.
fh : int, list or np.array, optional (default=None)
The forecasters horizon with the steps ahead to to predict.
X : pd.DataFrame, optional (default=None)
Exogenous variables are ignored
Returns
-------
self : returns an instance of self.
"""
self._set_y_X(y, X)
if X is not None:
raise NotImplementedError(
"Exogenous variables `X` are not yet supported.")
self._set_fh(fh)
if len(self.fh.to_in_sample(self.cutoff)) > 0:
raise NotImplementedError(
"In-sample predictions are not implemented")
self.step_length_ = check_step_length(self.step_length)
self.window_length_ = check_window_length(self.window_length)
# for the multioutput reduction strategy, a single forecaster is fitted
# simultaneously to all the future steps in the forecasting horizon
# by reducing to a forecaster that can handle multi-dimensional outputs
self._cv = SlidingWindowSplitter(
fh=self.fh.to_relative(self.cutoff),
window_length=self.window_length_,
step_length=self.step_length_,
start_with_window=True,
)
# transform data using rolling window split
X, Y_train = self._transform(y, X)
# fit regressor to training data
regressor = clone(self.regressor)
regressor.fit(X, Y_train)
self.regressor_ = regressor
self._is_fitted = True
return self
def get_cutoffs(self, y=None):
"""Get the cutoff time points.
Parameters
----------
y : pd.Series or pd.Index, optional (default=None)
Returns
-------
cutoffs : np.array
"""
if y is None:
raise ValueError(
f"{self.__class__.__name__} requires `y` to compute the "
f"cutoffs.")
y = self._check_y(y)
end = self._get_end(y)
start = self._get_start()
step_length = check_step_length(self.step_length)
return np.arange(start, end, step_length) - 1
