PIVMat Getting Started |
The PIVMat Toolbox contains a set of command-line functions to import, post-process and analyse 2D fluid flows velocity fields from LaVision's DaVis PIV (particle image velocimetry) software. It enables to handle and perform operations over large amount of velocity fields, and to produce high-quality vector/scalar outputs. The PIVMat Toolbox in itself does not perform any PIV computations.
DaVis (Data Acquisition and Visualization Software) is a general purpose commercial software developed by LaVision GmbH. In its PIV (particle image velocimetry) use, DaVis computes velocity fields from images of particles. These velocity fields can be saved in a specific DaVis file format (VEC or VC7 files), which can be imported in MATLAB with the ReadIMX Loader package provided by LaVision. Based on this package, the PIVMat Toolbox offers a number of command-line functions to further post-process and analyse the data from DaVis.
The first step of the PIVMat Toolbox is to import DaVis VEC or VC7 files into a MATLAB structure (or structure array) using the function loadvec (or loadset). This structure contains the velocity fields, axes, units etc., and can be processed by several functions of the toolbox.
Once imported, the velocity fields can be displayed using showvec, or converted into scalar fields using vec2scal.
A sample directory, named sample, with 3 VC7 fields, is provided with the toolbox to test the following examples (note that all the commands work with both VEC and VC7 files).
v = loadvec('B00001.VC7'); % loads the file B00001.VC7
showvec(v); % displays it
curl = vec2scal(filterf(v,2),'rot'); % computes the filtered vorticity
figure, showscal(curl); % displays it
Various statistics may be computed from vector and scalar fields:
v = loadvec('sample/*.vc7'); % loads all the directory sample
curl = vec2scal(filterf(v,2),'rot'); % computes the filtered vorticity
showscal(curl); % displays it as a movie
showscal(averf(curl)); % displays its ensemble-average
histscal_disp(curl); % displays its histogram
statf(v) % computes some statistics
Go to the Frequently Asked Questions section or to the Function by category section to learn more about this toolbox.
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