This function will push a mapper onto the stack which can then be used to compute the circular mean of all the values found in each sliding window. The associated location is the centroid of all the encountered locations. The associated elevation is the mean of the encountered elevations.
The mapper function produced by
mapper.mean.circular can only be applied to values of type LONG or DOUBLE, when applied to STRING
or BOOLEAN it does not return any value.
If any tick is undefined, no value will be returned. Use
mapper.mean.circular.exclude-nulls if your sliding windows may contain nulls.
mapper.mean.circular function expects a positive, finite, numeric period on top of the stack, this period will be used to determine the span
of circular values, use for example 360.0 if you wish to compute the circular mean of degree angles.