Local maxima (=crests) and local minima (= troughs) are identified in
a recorded wave data series. These form the turning points, which
can be extracted and analysed further to give wave cycles, wave lengths,
amplitudes, etc.


Rainflow cycles are identified. Small cycles can be removed by
means of rainflow filtering. The figure shows rainflow cycles with
amplitude exceeding one standard deviation of the wave data.


A cycle plot shows pairs of maxima and minima as points in the plane. 