NAME:
	medarr_mwb
 PURPOSE: (one line)
	Combine arrays with a median average.
 DESCRIPTION:
       This will combine a series of arrays into a single array by filling each
       pixel in the output array with the median of the corresponding pixels
       in the input arrays.
 CATEGORY:
	CCD data processing
 CALLING SEQUENCE:
       medarr_mwb, inarr, outarr
 INPUTS:
       inarr  -- A three dimensional array containing the input arrays to
                 combine together.  Each of the input arrays must be two
                 dimensional and must have the same dimensions.  These arrays
                 should then be stacked together into a single 3-D array,
                 creating INARR.
 OPTIONAL INPUT PARAMETERS:
	None.
 KEYWORD INPUT PARAMETERS:
  NTOPCLIP - If supplied, indicates how many of the brightest points in
                each pixel to remove before calculating the median.
                (default=0).  Warning: this may not play nice with
                an input badmask.
 KEYWORD PARAMETERS:
     BAD- a badmask, an byte or integer array with the dimensions of inarr.
       Non-zero values will correspond to pixels NOT to be included in the
       median stack. If all pixels for a stack are deleted, the corresponding 
       position of the output array is zero.
 
 OUTPUTS:
       outarr -- The output array.  It will have dimensions equal to the
                 first two dimensions of the input array.  The type of the
                 output is always floating point.
 COMMON BLOCKS:
	None.
 SIDE EFFECTS:
	None.
 RESTRICTIONS:
	This will run VERY slow if inarr and outarr won't fit into real memory
	on your computer.  Don't try this using virtual memory.
 PROCEDURE:
       The output array is created and then each pixel is extracted from the
	cube.  Once extracted, the pixel stack is sorted and the middle value
	is put into the output array.
 MODIFICATION HISTORY:
	Written by Marc W. Buie, Lowell Observatory, 1992 Jan 17
  2000/11/19, MWB, renamed to avoid name conflict with Astron library
  2007/09/07, MWB & PLC, added BAD keyword support
  2011/12/12, MWB, modified to add NTOPCLIP keyword