Script to create a histogram of velocity residuals using a GLOBK prt file as input.
 
   The default is to plot the cumulative histogram of residuals and together 
   with the theoretical chi curve of probabilities for either the 1-d (E,N,H) 
   or 2-d (horizontal velocity magnitude) chi-square distribution 
 
    sh_velhist -f <file> -ps <psfile> -c <comp> -sig <maxsig> -rat <maxrat> -vel <maxvel> -noabs -nocum -val -noerase 
 
      file   : Input GLOBK prt, org or vel
 
      psfile : Name for output postscript file 
 
      comp   : Component to extract < E N H or V > where V (default) is the horizontal magnitude 
  
      maxsig : Maximum sigma of the selected component to include (default 10 mm/yr)
  
      maxrat : Maximum ratio (value/sigma) to include (default 3)
  
      maxvel : Maximum absolute value of the residual velocity to include (default 10 mm/yr)
  
      -noabs : Don't take the absolute value (E, N, H); default is absolute value 
 
      -nocum : Plot the actual (not cumulative) distribution (vertical axis is number, not percent
 
      -val   : Plot the actual residuals (mm) rather than the ratio of residual to uncertainty
 
      -noerase: Do not remove the outhist, tmp.chivals, and vel2hist.rms files 
 
      -scalesig: Scale the uncertainties by this factor (default 1.0)
 
  Requirements:  GMT and the gamit/utils programs vel2hist and chicurve