NAME

     thresh  - module to set minimum value on a velocity field

SYNOPSIS

     thresh [ -Nntap ] [ -Ootap ] [  -nsnstr  ]  [  -nenetr  ]  [
     -rsnrst ] [ -renred ] [ -threshthresh ] [ -V ] [ -h ] [ -? ]

DESCRIPTION

     thresh reads a velocity field and sets any value  less  than
     thresh to thresh.

     It implements the following equation
          y(i) = max (thresh, x(i))

     where thresh is a user-defined parameter.

     thresh gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     starting and ending traces, starting and ending records  and
     verbose printout, if desired.

  Command line arguments
     -Nntap
          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'.

     -Ootap
          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).

     -threshthresh
          Enter the minimum value desired for the   output  velo-
          city file.  All values less than this value will be set
          to this value.  For example, any value less  than  1480
          (like  zero,  for  instance),  will  be  set  to  1480.
          Default is 1480.

     -nsnstr
          Enter the start trace number.  The default is the first
          trace of the record.

     -nenetr
          Enter the end trace number. The  default  is  the  last
          trace of the record.


     -rsnrst
          Enter start record number.  Default value is the  first
          record.

     -renred
          Enter end record number.  Default value is last record.

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

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

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

BUGS

     None known.

AUTHOR

     Gary Murphy

COPYRIGHT

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