NAME

     reduce  - reduce usp formatted data by a tracewise best  fit
     linear  regression  and  optionally  plot a map of estimated
     intercepts and slopes.

SYNOPSIS

     reduce [ -Nntap ] [ -Ootap ] [ -Mmtap ] [ -sist ] [ -eiend ]
     [  -rsrecord_start  ] [ -rerecord_end ] [ -nstrace_start ] [
     -netrace_end    ]    [    -swinstart_model_window    ]     [
     -ewinend_model_window ] [ -V ] [ -h, -? ]

DESCRIPTION

     reduce usp formatted data by calculating a best fit line  to
     each trace and removing that line from the data.  The module
     has the option to output the estimated intercepts and  slope
     (sample  1 and 2, respectively).  The user can use the -ewin
     and -swin options to design the line on  only  part  of  the
     data and remove it from the entire trace.

     reduce gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the optional file name containing intecepts and slopes,  the
     model window 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).

     -M mtap
          Enter the output data  set  name  or  file  immediately
          after typing -M.  This output file is optional and con-
          tains the estimated trace intercept and slope  (respec-
          tively) for the entire input data set.  The output data
          set also requires the full path name (see above).

     -s ist
          Enter the global start time (or depth)  of  the  reduc-
          tion.  Default = first sample.

     -e end
          Enter the global end time (or depth) of the  reduction.
          Default = last sample.

     -rs record_start
          Enter the start record number.   Record  numbers  below
          this value will not be processed.  The default is 1.

     -rs record_end
          Enter the end record number.  Record numbers above this
          value  will  not  be  processed.   The  default is last
          record.

     -ns trace_start
          Enter the start trace number.  Trace numbers below this
          value will not be processed.  The default is 1.

     -ns trace_end
          Enter the end trace number.  Trace numbers  above  this
          value  will  not  be  processed.   The  default is last
          trace.

     -swin start_model_window
          Enter the global start time (or  depth)  of  the  model
          window.  Default = first sample.

     -ewin end_model_window
          Enter the global end time (or depth) of the model  win-
          dow.  Default = last sample.

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

BUGS

     unknown

ALSO SEE

     zderiv, diffr, intdg, vstak

AUTHOR

     James M. Gridley

COPYRIGHT

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