Function overlap

dask/array/_array_expr/_overlap.py:390–475

Share boundaries between neighboring blocks Parameters ---------- x: da.Array A dask array depth: dict The size of the shared boundary per axis boundary: dict The boundary condition on each axis. Options are 'reflect', 'periodic', 'nearest', 'non

(x, depth, boundary, *, allow_rechunk=True)

def overlap(x, depth, boundary, *, allow_rechunk=True):
    """Share boundaries between neighboring blocks

    Parameters
    ----------

    x: da.Array
        A dask array
    depth: dict
        The size of the shared boundary per axis
    boundary: dict
        The boundary condition on each axis. Options are 'reflect', 'periodic',
        'nearest', 'none', or an array value.  Such a value will fill the
        boundary with that value.
    allow_rechunk: bool, keyword only
        Allows rechunking, otherwise chunk sizes need to match and core
        dimensions are to consist only of one chunk.

    The depth input informs how many cells to overlap between neighboring
    blocks ``{0: 2, 2: 5}`` means share two cells in 0 axis, 5 cells in 2 axis.
    Axes missing from this input will not be overlapped.

    Any axis containing chunks smaller than depth will be rechunked if
    possible, provided the keyword ``allow_rechunk`` is True (recommended).

    Examples
    --------
    >>> import numpy as np
    >>> import dask.array as da

    >>> x = np.arange(64).reshape((8, 8))
    >>> d = da.from_array(x, chunks=(4, 4))
    >>> d.chunks
    ((4, 4), (4, 4))

    >>> g = da.overlap.overlap(d, depth={0: 2, 1: 1},
    ...                       boundary={0: 100, 1: 'reflect'})
    >>> g.chunks
    ((8, 8), (6, 6))

    >>> np.array(g)
    array([[100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
           [100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
           [  0,   0,   1,   2,   3,   4,   3,   4,   5,   6,   7,   7],
           [  8,   8,   9,  10,  11,  12,  11,  12,  13,  14,  15,  15],
           [ 16,  16,  17,  18,  19,  20,  19,  20,  21,  22,  23,  23],
           [ 24,  24,  25,  26,  27,  28,  27,  28,  29,  30,  31,  31],
           [ 32,  32,  33,  34,  35,  36,  35,  36,  37,  38,  39,  39],
           [ 40,  40,  41,  42,  43,  44,  43,  44,  45,  46,  47,  47],
           [ 16,  16,  17,  18,  19,  20,  19,  20,  21,  22,  23,  23],
           [ 24,  24,  25,  26,  27,  28,  27,  28,  29,  30,  31,  31],
           [ 32,  32,  33,  34,  35,  36,  35,  36,  37,  38,  39,  39],
           [ 40,  40,  41,  42,  43,  44,  43,  44,  45,  46,  47,  47],
           [ 48,  48,  49,  50,  51,  52,  51,  52,  53,  54,  55,  55],
           [ 56,  56,  57,  58,  59,  60,  59,  60,  61,  62,  63,  63],
           [100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100],
           [100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100]])
    """