gpiv_vorstra - Calculates the differential quantities vorticity, shear
strain and normal strain from PIV data.
gpiv_vorstra [-d N] [-h | --help] [-n | -o | -s] [--no_g ] [-p |
--print] [-g | --g] [-v | --version] [filename] < stdin > stdout
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 to calculate vorticity, but no strain. The output can be
generated as ASCII data containing four columns or as GNUPlot Data
format that allows 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.
-d N Differential type to be used: central difference (N=0), least
squares (N=1), Richardson interpolation (N=2), circulation
-h | --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
-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
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.
Gerber Van der Graaf
8 November 2006