Files
pytorch-ts/pts/feature/time_feature.py
T
2019-10-30 09:42:02 +01:00

140 lines
3.6 KiB
Python

from abc import ABC, abstractmethod
from typing import List
import numpy as np
import pandas as pd
from .utils import get_granularity
class TimeFeature(ABC):
def __init__(self, normalized: bool = True):
self.normalized = normalized
@abstractmethod
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
pass
class MinuteOfHour(TimeFeature):
"""
Minute of hour encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.minute / 59.0 - 0.5
else:
return index.minute.map(float)
class HourOfDay(TimeFeature):
"""
Hour of day encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.hour / 23.0 - 0.5
else:
return index.hour.map(float)
class DayOfWeek(TimeFeature):
"""
Hour of day encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.dayofweek / 6.0 - 0.5
else:
return index.dayofweek.map(float)
class DayOfMonth(TimeFeature):
"""
Day of month encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.day / 30.0 - 0.5
else:
return index.day.map(float)
class DayOfYear(TimeFeature):
"""
Day of year encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.dayofyear / 364.0 - 0.5
else:
return index.dayofyear.map(float)
class MonthOfYear(TimeFeature):
"""
Month of year encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.month / 11.0 - 0.5
else:
return index.month.map(float)
class WeekOfYear(TimeFeature):
"""
Week of year encoded as value between [-0.5, 0.5]
"""
def __call__(self, index: pd.DatetimeIndex) -> np.ndarray:
if self.normalized:
return index.weekofyear / 51.0 - 0.5
else:
return index.weekofyear.map(float)
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.
"""
_, granularity = get_granularity(freq_str)
if granularity == "M":
feature_classes = [MonthOfYear]
elif granularity == "W":
feature_classes = [DayOfMonth, WeekOfYear]
elif granularity in ["D", "B"]:
feature_classes = [DayOfWeek, DayOfMonth, DayOfYear]
elif granularity == "H":
feature_classes = [HourOfDay, DayOfWeek, DayOfMonth, DayOfYear]
elif granularity in ["min", "T"]:
feature_classes = [MinuteOfHour, HourOfDay, DayOfWeek, DayOfMonth, DayOfYear]
else:
supported_freq_msg = f"""
Unsupported frequency {freq_str}
The following frequencies are supported:
M - monthly
W - week
D - daily
H - hourly
min - minutely
"""
raise RuntimeError(supported_freq_msg)
return [cls() for cls in feature_classes]