NAME

     partition  - partition records of a prestack dataset using a
     real  data  pad.  Keywords:  partition,  pad, split, window,
     restore

SYNOPSIS

     partition [ -Nntap ] [ -Ootap ] [ -ntrntr ] [ -npadnpad ]  [
     -R ] [ -V ] [ -? -h -help ]

DESCRIPTION

     partition takes an input USP formatted file  and  generates,
     for each input record, output records containing overlapping
     running windows of the input data. For  large  records  this
     may  be  necessary to allow memory intensive processes [like
     tfdnoise] to be run more efficiently.  One may also use this
     approach  to  employ  2d filtering techniques to handle spa-
     tially variant  coherent  noise  within  large  records.  By
     invoking  the -R option the data is restored to its original
     data trace/record structure. The first  and  last  trace  of
     each  record  is used for the pad on the windows at each end
     of the record.  Within the record the pads are  made  up  of
     spatially  contiguous  sections  of  the input record.  This
     allows edge effects of processing to be contained within the
     pad.   When  run  with -R the pad is stipped off, along with
     any edge effects, and the original record is  reconstructed.
     At  no  time are any of the input trace header entries modi-
     fied.  This program does make  use  of  the  following  line
     header entries however so be careful:

      Nx_Pad, NxLine, Nx_Rec, Nx_Trc, Nx_Win

     partition  gets  parameters  from  command  line  arguments.
     These  arguments  specify  the  input, output, the number of
     traces in the analysis window, the number of  traces  to  be
     padded, and verbose printout if desired.

  Command line arguments
     -N ntap
          Enter the input data set name or file immediately after
          typing -N.  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 'vsp' stored on the 'b' disk.

     -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).

     -ntr ntr
          Enter the number of traces to be included in the output
          analysis  records  (windows)  if there were no overlap.
          (Default=200).

     -npad npad
          Enter the number of traces  to  be  used  to  pad  each
          analysis  record.  The  pad  should  be large enough to
          minimize any subsequent filter edge effects (eg from fk
          filtering) upon restoration. npad will be changed to be
          an odd number and stored in line header location Nx_Pad
          for  use when invoking -R option. (Default =21 for for-
          ward  windowing,  drawn  from  trace  header  with   -R
          option).

     -R   Enter this option if the data are  to  be  restored  to
          their original, unpadded mode.

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

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

BUGS

     unknown

SEE ALSO

      rwindow, splitr, gather

AUTHOR

      Paul G.A. Garossino, Sept 2000
      modified from rwindow by [K. Marfurt]