NAME

     pptrn - Compute a Velocity Trendline in Log Space

SYNOPSIS

     pptrn [-VELntap] [-VTRotap] [-wvwatvel] [-vava]  [-zaza]  [-
     vbvb]  [-zbzb]  [-vcvc]  [-zczc]  [-vdvd] [-zdzd] [-veve] [-
     zeze] [-vfvf] [-zfzf] [-vgvg]  [-zgzg]  [-vhvh]  [-zhzh]  [-
     vivi]  [-zizi]  [-vjvj]  [-zjzj]  [-vkvk] [-zkzk] [-vlvl] [-
     zlzl] [-V] [-?]  [-h]

DESCRIPTION

     Given a velocity field and two or more velocity/depth  pairs
     this  program will create a velocity trendline in log space.
     The velocity/depth pairs should be selected such  that  they
     will  represent the part of the trendline that does not have
     curvature when viewed in linear space.  Both the  input  and
     the output datasets are USP formatted.

     pptrn gets its dataset names and its parameters from command
     line  arguments.   This  program  expects  the  header value
     "Dz1000" to be present in the line header.

  Command line arguments
     -VELntap
          Enter the name of the input velocity field after typing
          -VEL.  This input file should include the complete path
          name if the file  resides  in  a  different  directory.
          Example  -L/b/vsp/dummy  tells  the program to look for
          file 'dummy' in directory 'vsp' stored on the 'b' disk.

     -VTRotap
          Enter the name of the output velocity  trendline  field
          after  typing -VTR. This dataset also requires the full
          pathname (see above).  The velocity  trendline  dataset
          will be the same size as the input velocity dataset.

     -wvwv
          Enter the water velocity after typing -wv.   The  velo-
          city  trendline will never be less than the water velo-
          city.

     -vava
          The parameters va,za and vb,zb are  the  velocity/depth
          points  used  to  create the velocity trendline.  Enter
          the first velocity after typing -va. No default.

     -zaza
          Enter the first depth after typing -za.  No default.

     -vbvb
          Enter  the  second  velocity  after  typing  -vb.    No
          default.

     -zbzb
          Enter the second depth after typing -zb.  No default.

     -vc -zc -vd -zd -ve -ze -vf -zf

     -vg -zg -vh -zh -vi -zi -vj -zj

     -vk -zk -vl -zl
          These flags are available for entering up to  10  addi-
          tional velocity/depth points if desired.

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

     -?   Enter this (or '-?' if you are running in  c-shell)  to
          get  online  help.   The  program  will terminate after
          printing this.

     -h   Enter this option to get online help.  The program will
          terminate after printing this.

SEE ALSO

     vel2den, ppdenobg, ppetn, pptrnehz

BUGS

     None known.

AUTHOR

     Mary Ann Thornton

COPYRIGHT

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