NAME

     xorder  - reorder records in ascending offset (and inverse)

SYNOPSIS

     xorder [ -Nntap ] [ -Ootap ] [ -R ] [ -V ] [ -? ]

DESCRIPTION

     xorder in forward  mode  reorders  the  input  records  into
     ascending trace distance. In inverse mode the original trace
     order is restored. This is useful in a  number  of  applica-
     tions  which  insist  on  a  dense  packing  of live ordered
     traces.

     In forward mode the dead traces end up at  the  end  of  the
     record;  in inverse mode the dead traces are properly inter-
     spersed with the live traces.

     xorder gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     forward/inverse modes, and verbose printout, if desired.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing -N unless the input is from a pipe in which case
          the -N entry must be omitted.  This input  file  should
          include the complete path name if the file resides in a
          different directory.  Example -N/b/vsp/dummy tells  the
          program to look for file 'dummy' in directory '/b/vsp'.

     -O otap
          Enter the output data  set  name  or  file  immediately
          after typing -O.  This output file is not required when
          piping the output to another process.  The output  data
          set also requires the full path name (see above).

     -R   Enter the command line argument '-R' to do the  inverse
          operation.

     -V   Enter the command line argument '-V' to get  additional
          printout.

     -?   Enter the command line  argument  '-?'  to  get  online
          help.   The program terminates after the help screen is
          printed.

BUGS

     If there are dead traces among the live in the input records
     these will end up at the end of the output after a full cir-
     cle forward and inverse operation.

SEE ALSO

     disort

AUTHOR

     Paul Gutowski, EPTG (3146), zprg03@trc.amoco.com

COPYRIGHT

     copyright 2001, Amoco Production Company
               All Rights Reserved
          an affiliate of BP America Inc.