NAME

     mixrec  - do simple mixing on seismic records

SYNOPSIS

     mixrec [ -Nntap ] [ -Ootap ] [ -mmix ] [ -wamp ] [ -sist ] [
     -eied  ]  [ -nsns ] [ -nene ] [ -rsirs ] [ -reire ] [ -D ] [
     -V ] [ -? -h -help  ]

DESCRIPTION

     mixrec computes a simple odd-length 1/x type filter and con-
     volves  this  spatially  with  seismic  traces read from the
     input.  The center  value  of  the  filter  is  always  1.0.
     Values  on  either side of the center value are now computed
     by raising amp to the ith power as i  increments  away  from
     the center value.

     This program works  on  seismic  records,  each  of  several
     traces  (e.g. pre-stack data); to use on post-stack data use
     utop or rwindow to form the input single trace records  into
     multitrace  records.  There is a companion program that does
     the same type of mixing but works only  on  seismic  traces,
     i.e.  it  mixes  samples  in time. That program can also mix
     spatially but you have to run transp | mixn | transp

     mixrec gets both its data and its  parameters  from  command
     line  arguments.  These arguments specify the input, output,
     the filter length, the filter  weight,  the  start  and  end
     traces, 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 mix
          Enter the odd length of the  mixing  filter  in  points
          (default = 3).

     -w amp
          Enter  the  filter  weight  in  the  range  0.0  -  1.0
          (default = 0.5).  If this entry is greater than 1.0 the
          program will assume it is meant to  be  a  percent  and
          convert  to  a fraction.  This is useful when inputting
          to scripts when integers not reals are handled.

     -s ist
          Enter the start time (ms) for mixing. Times above  this
          will be passed untouched. Default = first sample.

     -e ied
          Enter the end time (ms) for mixing.  Times  below  this
          will be passed untouched. Default = last sample.

     -ns ns
          Enter the start trace for mixing.  Traces  before  this
          will be passed untouched. Default = first trace in each
          record.

     -ne ne
          Enter the end trace for mixing. Traces after this  will
          be  passed  untouched.  Default  =  last  trace in each
          record.

     -rs irs
          Enter the start record for mixing. Records before  this
          will  be  passed  untouched.  Default = first record in
          data set.

     -re ire
          Enter the end record for  mixing.  Records  after  this
          will be passed untouched. Default = last record in data
          set.

     -D   Enter the command line argument '-D' to process records
          with  dead  traces  embedded; otherwise dead traces are
          stripped  from  the  records  before   processing   and
          inserted after mixing.

     -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

     There is no provision for removing dead trace flag from out-
     put traces that may not be dead after this process.

SEE ALSO

     mixn

AUTHOR

     P. R. Gutowski (at Felinski's request)

COPYRIGHT

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