Mappings between file dataspaces/selections and memory dataspaces/selections.
(c) A sequence of points from a 2D array to a sequence of points in a 3D array.
(d) Union of hyperslabs in file to union of hyperslabs in memory. Number of elements must be equal.
(b) A regular series of blocks from a 2D array to a contiguous sequence at a certain offset in a 1D array
(a) A hyperslab from a 2D array to the corner of a smaller 2D array