| from typing import List |
|
|
| import numpy as np |
| import pandas as pd |
| from pandas.tseries import offsets |
| from pandas.tseries.frequencies import to_offset |
|
|
|
|
| class TimeFeature: |
| def __init__(self): |
| pass |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| pass |
|
|
| def __repr__(self): |
| return self.__class__.__name__ + "()" |
|
|
|
|
| class SecondOfMinute(TimeFeature): |
| """Minute of hour encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return index.second / 59.0 - 0.5 |
|
|
|
|
| class MinuteOfHour(TimeFeature): |
| """Minute of hour encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return index.minute / 59.0 - 0.5 |
|
|
|
|
| class HourOfDay(TimeFeature): |
| """Hour of day encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return index.hour / 23.0 - 0.5 |
|
|
|
|
| class DayOfWeek(TimeFeature): |
| """Hour of day encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return index.dayofweek / 6.0 - 0.5 |
|
|
|
|
| class DayOfMonth(TimeFeature): |
| """Day of month encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return (index.day - 1) / 30.0 - 0.5 |
|
|
|
|
| class DayOfYear(TimeFeature): |
| """Day of year encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return (index.dayofyear - 1) / 365.0 - 0.5 |
|
|
|
|
| class MonthOfYear(TimeFeature): |
| """Month of year encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return (index.month - 1) / 11.0 - 0.5 |
|
|
|
|
| class WeekOfYear(TimeFeature): |
| """Week of year encoded as value between [-0.5, 0.5]""" |
|
|
| def __call__(self, index: pd.DatetimeIndex) -> np.ndarray: |
| return (index.isocalendar().week - 1) / 52.0 - 0.5 |
|
|
|
|
| def time_features_from_frequency_str(freq_str: str) -> List[TimeFeature]: |
| """ |
| Returns a list of time features that will be appropriate for the given frequency string. |
| Parameters |
| ---------- |
| freq_str |
| Frequency string of the form [multiple][granularity] such as "12H", "5min", "1D" etc. |
| """ |
|
|
| features_by_offsets = { |
| offsets.YearEnd: [], |
| offsets.QuarterEnd: [MonthOfYear], |
| offsets.MonthEnd: [MonthOfYear], |
| offsets.Week: [DayOfMonth, WeekOfYear], |
| offsets.Day: [DayOfWeek, DayOfMonth, DayOfYear], |
| offsets.BusinessDay: [DayOfWeek, DayOfMonth, DayOfYear], |
| offsets.Hour: [HourOfDay, DayOfWeek, DayOfMonth, DayOfYear], |
| offsets.Minute: [ |
| MinuteOfHour, |
| HourOfDay, |
| DayOfWeek, |
| DayOfMonth, |
| DayOfYear, |
| ], |
| offsets.Second: [ |
| SecondOfMinute, |
| MinuteOfHour, |
| HourOfDay, |
| DayOfWeek, |
| DayOfMonth, |
| DayOfYear, |
| ], |
| } |
|
|
| offset = to_offset(freq_str) |
|
|
| for offset_type, feature_classes in features_by_offsets.items(): |
| if isinstance(offset, offset_type): |
| return [cls() for cls in feature_classes] |
|
|
| supported_freq_msg = f""" |
| Unsupported frequency {freq_str} |
| The following frequencies are supported: |
| Y - yearly |
| alias: A |
| M - monthly |
| W - weekly |
| D - daily |
| B - business days |
| H - hourly |
| T - minutely |
| alias: min |
| S - secondly |
| """ |
| raise RuntimeError(supported_freq_msg) |
|
|
|
|
| def time_features(dates, freq='h'): |
| return np.vstack([feat(dates) for feat in time_features_from_frequency_str(freq)]) |
|
|