This plugin allows to analyze local direction and frequency of sinusoidal waves. The output are optionally smoothed lambda (inversely proportional to the frequency) and phi (direction in degrees).
See also http://www.optinav.info/Helmholtz_Analysis.htm
Example
With an artificial example input like this:
and parameters like this:
the Helmholtz Analysis plugin produces the local estimates:
and the smoothed versions thereof:
