def offset(image, d)

gistfile1.pyw

def offset(image, d):
    """
    Create a subview of image where the indices are offset by (a tuple) d.
    
    Assume you needed to select all the items in a 3-D numpy.ndarray arr
    which have neighbors at a distance d = (i, j, k). You can easily view
    those items calling:
        offset(arr, (-i, -j, -k)).
    The neighbors are then, respectively:
        offset(arr, d)
    
    (Using the helper class vec, http://gist.github.com/356316, might help
    even further, simplifying the negative offset to just -d.)
    
    Example:
    >>> from numpy import arange, reshape
    >>> x = arange(15).reshape(5,3)
    >>> x
    array([[ 0,  1,  2,  3,  4],
           [ 5,  6,  7,  8,  9],
           [10, 11, 12, 13, 14]])
    >>> offset(x, (1,2))
    array([[ 7,  8,  9],
           [12, 13, 14]])
    >>> offset(x, (-1,2))
    array([[2, 3, 4],
           [7, 8, 9]])
    >>> offset(x, (-1,2)) - offset(x, (1,2))
    array([[-5, -5, -5],
           [-5, -5, -5]])
    """
    return image[[slice(0,i) if (i < 0) else slice(i,None) for i in d]]