r.contour

Is there any way to force r.contour to ignore MASKed areas? Or
impose a cell value as invalid so as to prevent contouring in a
cell or group of cells?

Also, is there any method of exporting r.contour output and have the
export routine clip based on a MASK? (e.g. v.out.ascii or v.out.dlg)

Wayne Gibson
Oregon State University