Function map_blocks

dask/array/core.py:551–1025

Map a function across all blocks of a dask array. Note that ``map_blocks`` will attempt to automatically determine the output array type by calling ``func`` on 0-d versions of the inputs. Please refer to the ``meta`` keyword argument below if you expect that the function will not su

(
    func,
    *args,
    name=None,
    token=None,
    dtype=None,
    chunks=None,
    drop_axis=None,
    new_axis=None,
    enforce_ndim=False,
    meta=None,
    **kwargs,
)

def map_blocks(
    func,
    *args,
    name=None,
    token=None,
    dtype=None,
    chunks=None,
    drop_axis=None,
    new_axis=None,
    enforce_ndim=False,
    meta=None,
    **kwargs,
):
    """Map a function across all blocks of a dask array.

    Note that ``map_blocks`` will attempt to automatically determine the output
    array type by calling ``func`` on 0-d versions of the inputs. Please refer to
    the ``meta`` keyword argument below if you expect that the function will not
    succeed when operating on 0-d arrays.

    Parameters
    ----------
    func : callable
        Function to apply to every block in the array.
        If ``func`` accepts ``block_info=`` or ``block_id=``
        as keyword arguments, these will be passed dictionaries
        containing information about input and output chunks/arrays
        during computation. See examples for details.
    args : dask arrays or other objects
    dtype : np.dtype, optional
        The ``dtype`` of the output array. It is recommended to provide this.
        If not provided, will be inferred by applying the function to a small
        set of fake data.
    chunks : tuple, optional
        Chunk shape of resulting blocks if the function does not preserve
        shape. If not provided, the resulting array is assumed to have the same
        block structure as the first input array.
    drop_axis : number or iterable, optional
        Dimensions lost by the function.
    new_axis : number or iterable, optional
        New dimensions created by the function. Note that these are applied
        after ``drop_axis`` (if present). The size of each chunk along this
        dimension will be set to 1. Please specify ``chunks`` if the individual
        chunks have a different size.
    enforce_ndim : bool, default False
        Whether to enforce at runtime that the dimensionality of the array
        produced by ``func`` actually matches that of the array returned by
        ``map_blocks``.
        If True, this will raise an error when there is a mismatch.
    token : string, optional
        The key prefix to use for the output array. If not provided, will be
        determined from the function name.
    name : string, optional
        The key name to use for the output array. Note that this fully
        specifies the output key name, and must be unique. If not provided,
        will be determined by a hash of the arguments.
    meta : array-like, optional
        The ``meta`` of the output array, when specified is expected to be an