NAME

       gpiv_vorstra  - Calculates the differential quantities vorticity, shear strain and normal strain from PIV
       data.

SYNOPSIS

       gpiv_vorstra [-d N] [-h | --help] [-n | -o | -s] [--no_g ] [-p | --print] [-g |  --g]  [-v  |  --version]
       [filename] < stdin > stdout

DESCRIPTION

       gpiv_vorstra  calculates  the differential quantities like vorticity, shear strain and normal strain from
       PIV data. You can choose from several  differential  schemes:  central  differentiation,  least  squares,
       Richardson  extrapolation  and  circulation  method.  Circulation  method  only  allows  one to calculate
       vorticity, but no strain. The output can be generated as ASCII data containing four columns or as GNUPlot
       Data format that allows one to view/print the data as contour plots.

       The configuration parameters (containing the POST key) may be overruled by the command line  options,  as
       explained below.

Options

       -d N   Differential  type  to  be  used:  central  difference  (N=0),  least  squares  (N=1),  Richardson
              interpolation (N=2), circulation method (N=3)

       -h | --help
              On-line help

       -n     Calculate normal strain of the PIV data. As an alternative  the  program  may  be  called  by  its
              nickname gpiv_nstrain. In combination with filename the output will be written to filename.nstr.

       -o     Calculate  vorticity  of the PIV data. As an alternative the program may be called by its nickname
              gpiv_vorty. In combination with filename the output will be written to filename.vor.

       -p | --print
              Print parameters, command line options and eventually used input and output filenames  to  stdout.
              The output is identic of filename.par, in case filename is used.

       -s     Calculate  shear  strain  of  the  PIV  data.  As  an alternative the program may be called by its
              nickname sstrain. In combination with filename the output will be written to filename.sstr.

       -g     Show contour plot of the output with gnuplot.

       --no_g Suppresses to show contour plot of the output with gnuplot.

       -v | --version
              Print version information on standard output, then exit successfully.

       filename
              Input PIV data file. Overrides stdin and stdout. The output will be written to  filename.vor  with
              -o, filename.nstr with -n or filename.sstr with -s.  Parameters are stored in filename.par and may
              be used for future use by including them in ./gpivrc.

SEE ALSO

       gpivtools

AUTHOR

       Gerber Van der Graaf

                                                 8 November 2006                                 GPIV_VORSTRA(1)