char* sdoc[] = {

 SUCMP   - CoMPare two seismic data sets, returns 0 to the shell	", 
             if the same and 1 if different				

  sucmp file_A file_B							

 Required parameters:							
      none								

   Optional parameters:						
      limit=1.0e-4    normalized difference threshold value		

 Notes:								
 This program is the seismic equivalent of the Unix cmp(1)		
 command.  However, unlike cmp(1), it understands seismic data		
 and will consider files which have only small numerical		
 differences to be the same.						

 Sucmp first checks that the number of traces and number of samples	
 are the same. It then compares the trace headers bit for bit.		
 Finally it checks that the fractional difference of A & B is		
 less than limit.							

 This program is intended as an aid in regression testing changes to	
 seismic processing programs.						

 Expected usage is in shell scripts or Makefiles, e.g.			
   #!/bin/sh								
    #-------------------------------------------------------		
    # Run a test data set and verify the result is correct		
    # If the data doesn't match show the data on the screen.		
   #-------------------------------------------------------		

  ./fubar par=tst1.par							
   sucmp tst1.su ref/tst1.su						
   if [ $? ]								
      then								
      suxwigb <tst1.su &						
      suxwigb <ref/tst1.su & "
   fi									


 Author:  Reginald H. Beardsley 
		rhb@acm.org

  sucmp - compare two seismic files in CWP/SU format to see if they
         are the same within the user specified limit.

  Algorithm:

  Loop over both input files comparing data values.  To be 
  considered the same files must have:

    - same number of traces
    - same number of samples per trace
    - trace values within limits of each other

 Note that the program exits as soon as the files fail to match.

 For readability, explicit temporary variables are used which the
 compiler will optimize away. Braces are used on all conditionals
 so that a breakpoint can be set to stop the debugger only if the 
 condition is true.

 Because of the overloading of trace header fields in CWP/SU, the
 headers are compared bit for bit.