NAME: 
  num_mag
 PURPOSE:   (one line only)
  Gives the relative number vs. magnitude of KBOs.
 DESCRIPTION:
  This is an approximation of the number of objects as a function of
  apparent magnitude.  The function is a power law and is intended to
  represent the large-size distribution of KBOs.  This function will be
  reasonable for a magnitude brighter than 26.
  This function is meant to be probabalistically sampled with smplprb.pro.
 CATEGORY:
  Miscellaneous
 CALLING SEQUENCE:
  array=num_mag(m)
 INPUTS:
  m      :Vector or scalar of magnitude values
 OPTIONAL INPUT PARAMETERS:
 KEYWORD INPUT PARAMETERS:
 OUTPUTS:
  array  :Returns an array of the same size as m. (when plotted it
             looks like an exponential function)
 KEYWORD OUTPUT PARAMETERS:
 COMMON BLOCKS:
 SIDE EFFECTS:
 RESTRICTIONS:
 PROCEDURE:
 MODIFICATION HISTORY:
  2004/07/13, Written by Maureen Teyssier, REU Lowell Observatory
  2004/07/15, MWB, incorporated into library.