"""Data check that checks whether the time series parameters are compatible with the data size."""
from evalml.data_checks import DataCheck, DataCheckError, DataCheckMessageCode
from evalml.utils.gen_utils import (
are_ts_parameters_valid_for_split,
contains_all_ts_parameters,
)
[docs]class TimeSeriesParametersDataCheck(DataCheck):
"""Checks whether the time series parameters are compatible with data splitting.
If `gap + max_delay + forecast_horizon > X.shape[0] // (n_splits + 1)`
then the feature engineering window is larger than the smallest split. This will cause the
pipeline to create features from data that does not exist, which will cause errors.
Args:
problem_configuration (dict): Dict containing problem_configuration parameters.
n_splits (int): Number of time series splits.
"""
def __init__(self, problem_configuration, n_splits):
is_valid, msg = contains_all_ts_parameters(problem_configuration)
if not is_valid:
raise ValueError(msg)
self.gap = problem_configuration["gap"]
self.forecast_horizon = problem_configuration["forecast_horizon"]
self.max_delay = problem_configuration["max_delay"]
self.n_splits = n_splits
[docs] def validate(self, X, y=None):
"""Check if the time series parameters are compatible with data splitting.
Args:
X (pd.DataFrame, np.ndarray): Features.
y (pd.Series, np.ndarray): Ignored. Defaults to None.
Returns:
dict: dict with a DataCheckError if parameters are too big for the split sizes.
Examples:
>>> import pandas as pd
The time series parameters have to be compatible with the data passed. If the window size (gap + max_delay +
forecast_horizon) is greater than or equal to the split size, then an error will be raised.
>>> X = pd.DataFrame({
... "dates": pd.date_range("1/1/21", periods=100),
... "first": [i for i in range(100)],
... })
>>> y = pd.Series([i for i in range(100)])
...
>>> problem_config = {"gap": 7, "max_delay": 2, "forecast_horizon": 12, "time_index": "dates"}
>>> ts_parameters_check = TimeSeriesParametersDataCheck(problem_configuration=problem_config, n_splits=7)
>>> assert ts_parameters_check.validate(X, y) == [
... {
... "message": "Since the data has 100 observations, n_splits=7, and a forecast horizon of 12, the smallest "
... "split would have 16 observations. Since 21 (gap + max_delay + forecast_horizon)"
... " >= 16, then at least one of the splits would be empty by the time it reaches "
... "the pipeline. Please use a smaller number of splits, reduce one or more these "
... "parameters, or collect more data.",
... "data_check_name": "TimeSeriesParametersDataCheck",
... "level": "error",
... "code": "TIMESERIES_PARAMETERS_NOT_COMPATIBLE_WITH_SPLIT",
... "details": {
... "columns": None,
... "rows": None,
... "max_window_size": 21,
... "min_split_size": 16,
... "n_obs": 100,
... "n_splits": 7
... },
... "action_options": []
... }
... ]
"""
messages = []
validation = are_ts_parameters_valid_for_split(
gap=self.gap,
max_delay=self.max_delay,
forecast_horizon=self.forecast_horizon,
n_splits=self.n_splits,
n_obs=X.shape[0],
)
if not validation.is_valid:
messages.append(
DataCheckError(
message=validation.msg,
data_check_name=self.name,
message_code=DataCheckMessageCode.TIMESERIES_PARAMETERS_NOT_COMPATIBLE_WITH_SPLIT,
details={
"max_window_size": validation.max_window_size,
"min_split_size": validation.smallest_split_size,
"n_obs": validation.n_obs,
"n_splits": validation.n_splits,
},
).to_dict(),
)
return messages
