Class DataArrayRolling

xarray/computation/rolling.py:261–770

class DataArrayRolling(Rolling["DataArray"]):
    __slots__ = ("window_labels",)

    def __init__(
        self,
        obj: DataArray,
        windows: Mapping[Any, int],
        min_periods: int | None = None,
        center: bool | Mapping[Any, bool] = False,
    ) -> None:
        """
        Moving window object for DataArray.
        You should use DataArray.rolling() method to construct this object
        instead of the class constructor.

        Parameters
        ----------
        obj : DataArray
            Object to window.
        windows : mapping of hashable to int
            A mapping from the name of the dimension to create the rolling
            window along (e.g. `time`) to the size of the moving window.
        min_periods : int, default: None
            Minimum number of observations in window required to have a value
            (otherwise result is NA). The default, None, is equivalent to
            setting min_periods equal to the size of the window.
        center : bool, default: False
            Set the labels at the center of the window. The default, False,
            sets the labels at the right edge of the window.

        Returns
        -------
        rolling : type of input argument

        See Also
        --------
        xarray.DataArray.rolling
        xarray.DataArray.groupby
        xarray.Dataset.rolling
        xarray.Dataset.groupby
        """
        super().__init__(obj, windows, min_periods=min_periods, center=center)

        # TODO legacy attribute
        self.window_labels = self.obj[self.dim[0]]

    def __iter__(self) -> Iterator[tuple[DataArray, DataArray]]:
        if self.ndim > 1:
            raise ValueError("__iter__ is only supported for 1d-rolling")

        dim0 = self.dim[0]
        window0 = int(self.window[0])
        offset = (window0 + 1) // 2 if self.center[0] else 1
        stops = np.arange(offset, self.obj.sizes[dim0] + offset)
        starts = stops - window0
        starts[: window0 - offset] = 0

        for label, start, stop in zip(self.window_labels, starts, stops, strict=True):