DPlot

Some time when I draw a contour plot (using shaded bands) I set my own limits for Z values instead using the default data range. I don't want dplot to draw anything beyond my range but dplot always fills the region with purple color. How can I solve this problem?

If you want to clip values outside some range in Z so that they aren't drawn at all, use Options>Extents/Intervals/Size, check "Specify extents", and enter the Z extents you're interested in.

If instead you DO want to draw those areas but you want to force Z to be between some extents, use Edit>Operate on Z with Z=min(<zmax>,max(<zmin>,z))