HELP ARRAY_FLIP                             David Young, April 2001


LIB *array_flip provides a procedure for obtaining the mirror image of
a two-dimensional array by flipping it about the x-axis or the y-axis
(or both, thus rotating it by 180 degrees).


array_flip(array, region, lr, ud, arrout) -> arrout
        array must be a 2-D array.

        region may be a 4-element list giving a region of array from
        which to take data (in *boundslist form), or <false> to specify
        the whole of array.

        On exit, the same region of arrout receives data from array. If
        lr is not <false>, the order of the columns is reversed in the
        output. If ud is not <false>, the order of the rows is reversed.

        On entry, arrout may be an array which is to receive the data,
        in which case its bounds must contain the whole of region (or
        the bounds of array if region is <false>). It must be able to
        accept data of the type stored in array. It may be the same
        array as array. Alternatively, arrout may be <false> on entry,
        in which case a new array with bounds given by region (or the
        bounds of array if region is <false>) and an arrayvector of the
        same type as array's arrayvector is created and returned.


--- $popvision/help/array_flip
--- Copyright University of Sussex 2001. All rights reserved.