Hi,
we have updated the r.param.scale module to floating point. This increases
the precision, and removes numerical problems with flat curvatures.
The updated version we tested with several synthetic surfaces such as
r.mapcalc surf="((((y()-5101500)^2)/350-((x()-1660500)^2)/400)+624)"
(you may enter different center coordinates)
The "feature" map remains integer type.
Cheers
Markus and Lorenzo