NAME¶
gpiv_scale - Scaling of PIV data.
SYNOPSIS¶
gpiv_scale [
-h |
--help] [
-p |
--print] [
-s M |
-S M] [
-t dT |
-T
dT] [
-v |
--version] [
-zp x0 y0] [
-zv x0 y0] [
filename] <
stdin >
stdout
DESCRIPTION¶
gpiv_scale applies the image magnification and the time between
successive recordings to the PIV estimators. This results that particle
displacements [px] are modified to velocities [m/s] and their positions from
[px] to [m]. A physical reference for the positions of the PIV data can be
applied by means of the image zero-offset option.
If
filename is used, the parameters and options to be used for
gpiv_scale are subsequently read from the image header (
filename .h in case of raw binary images) or from the
configuration resources (containing the
IMG and
POST keys). The
parameters may be overruled by the command line options, as explained below.
Options¶
- -h | --help
- On-line help.
- -p | --print
- Prints parameters, command line options and input and output filenames to
stdout. The output is identic of filename.par, in case
-f is used.
- -s M
- spatial scaling with magnification factor M [m/px]
- -S M
- Inverse spatial scaling with magnification factor M [m/px]; returns
scaled data to their original magnitudes.
- -v | --version
- Prints version information on standard output, then exits successfully.
- -t dT
- Translates particle displacements into velocities by devising them with
the time between subsequent recordings dT [s].
- -T dT
- Inverse time scaling. Returns velocities into displacements [px]
- [-z x0 y0]
- Relates the positions of the observations of velocities/displacements to a
physical location in the experiment by image zero offsetting. x0
y0 denote the physical position of pixel (0,0) in the image.
- filename
- Input PIV file. Overrides stdin and stdout. The output will be written to
filename.sc.piv. Parameters are stored in
filename.par and may be used for future use by including
them in ./gpivrc.
SEE ALSO¶
gpivtools
NOTES¶
AUTHOR¶
Gerber Van der Graaf
BUGS¶
The program has been tested for PIV data. So far, no bugs have been found.