Source code for scmdata.timeseries

TimeSeries handling

Functionality for handling and storing individual time-series

import copy
import datetime as dt
from typing import Any, Callable, List, Union

import numpy as np
import pint
import xarray as xr
from openscm_units import unit_registry as ur

from ._base import OpsMixin
from .time import TimePoints, TimeseriesConverter

class _Counter:
    def __init__(self):
        self.count = 0

    def __call__(self):
        val = self.count
        self.count += 1

        return val

    def reset(self):
        self.count = 0

get_default_name = _Counter()

[docs]class TimeSeries(OpsMixin): """ A 1D time-series with metadata Proxies an xarray.DataArray with a single time dimension """ def __init__(self, data, time=None, **kwargs): """ Initialise a :class:`TimeSeries` instance Parameters ---------- data : array_like Data to be held by the :class:`TimeSeries` instance. ``data`` must be one-dimensional. If ``data`` is an :class:`xarray.DataArray` instance, its single dimension must be ``"time"``. If ``data`` is not an :class:`xarray.DataArray`, then ``time`` must also be supplied. time : array_like or None Only used if ``data`` is not an :class:`xarray.DataArray`. These become the time axis of ``self._data``. **kwargs Only used if `data`` is not an :class:`xarray.DataArray`. Passed to the :class:`xarray.DataArray` constructor. Raises ------ ValueError ``data`` is not one-dimensional TypeError ``data`` is an :class:`xarray.DataArray` and ``time is not None`` ValueError ``data`` is an :class:`xarray.DataArray` and its dimension is not named ``"time"``. TypeError ``data`` is not an :class:`xarray.DataArray` and ``time is None`` ValueError ``data`` is not an :class:`xarray.DataArray` and ``coords`` is supplied via ``**kwargs`` """ values = np.asarray(data) if values.ndim != 1: raise ValueError("data must be 1d") if isinstance(data, xr.DataArray): if time is not None: raise TypeError( "If data is an :class:`xarray.DataArray` instance, time must be " "`None`" ) if data.dims != ("time",): raise ValueError( "If data is an :class:`xarray.DataArray` instance, its only " "dimension must be named `'time'`" ) self._data = data else: if time is None: raise TypeError( "If data is not an :class:`xarray.DataArray` instance, `time` " "must not be `None`" ) if "coords" in kwargs: raise ValueError( "If ``data`` is not an :class:`xarray.DataArray`, `coords` must " "not be supplied via `kwargs` because it will be " "automatically filled with the value of `time`." ) # Auto incrementing name if "name" not in kwargs: kwargs["name"] = get_default_name() if isinstance(time, tuple): time = list(time) self._data = xr.DataArray(values, coords=[("time", time)], **kwargs) def __repr__(self): return self._data.__repr__() @property def name(self): """ Timeseries name If no name was provided this will be an automatically incrementing number """ return def __len__(self): """ Length of the time-series (number of time points) Returns ------- int """ return len(self._data["time"])
[docs] def copy(self): """ Create a deep copy of the timeseries. Any further modifications to the :class:`Timeseries` returned copy will not be reflected in the current :class:`Timeseries` Returns ------- :class:`Timeseries` """ return copy.deepcopy(self)
@property def meta(self): """ Metadata associated with the timeseries Returns ------- dict """ return self._data.attrs @property def time_points(self): """ Time points of the data Returns ------- :class:`numpy.ndarray` """ return TimePoints(self._data.coords["time"].values) @property def values(self): """ Get the data as a numpy array Returns ------- :class:`numpy.ndarray` """ return self._data.values def __getitem__(self, item): res = self._data.__getitem__(item) if res.ndim == 0: return res return TimeSeries(res) def __setitem__(self, key, value): self._data.__setitem__(key, value) def _binary_op( self, other, f: Callable[..., Any], reflexive=False, **kwargs, ) -> Callable[..., "TimeSeries"]: other_data = getattr(other, "_data", other) if isinstance(other, pint.Quantity): try: self_data = self._data * ur(self.meta["unit"]) except KeyError: # let Pint assume dimensionless and raise an error as # necessary self_data = self._data else: self_data = self._data ts = f(self_data, other_data) if not reflexive else f(other_data, self_data) ts.attrs = self._data.attrs if isinstance(other, pint.Quantity): ts.attrs["unit"] = str( = return TimeSeries(ts) def _inplace_binary_op(self, other, f: Callable) -> Callable[..., "TimeSeries"]: other_data = getattr(other, "_data", other) f(self._data, other_data) return self
[docs] def reindex(self, time, **kwargs): """ Update the time dimension, filling in the missing values with NaN's This is different to interpolating to fill in the missing values. Uses `xarray.DataArray.reindex` to perform the reindexing Parameters ---------- time : `obj`:np.ndarray Time values to reindex the data to. Should be ``np.datetime64`` values **kwargs Additional arguments passed to xarray's DataArray.reindex function Returns ------- :class:`TimeSeries` A new TimeSeries with the new time dimension References ---------- """ return TimeSeries(self._data.reindex({"time": time}, **kwargs))
[docs] def interpolate( self, target_times: Union[np.ndarray, List[Union[dt.datetime, int]]], interpolation_type: str = "linear", extrapolation_type: str = "linear", ): """ Interpolate the timeseries onto a new time axis Parameters ---------- target_times Time grid onto which to interpolate interpolation_type: str Interpolation type. Options are 'linear' extrapolation_type: str or None Extrapolation type. Options are None, 'linear' or 'constant' Returns ------- :class:`TimeSeries` A new TimeSeries with the new time dimension """ target_times = TimePoints(target_times) timeseries_converter = TimeseriesConverter( self.time_points.values, target_times.values, interpolation_type=interpolation_type, extrapolation_type=extrapolation_type, ) ts = self.reindex(target_times.as_cftime()) ts._data[:] = timeseries_converter.convert_from(self._data.values) return ts