donuts - Vector format flaw!(?)

Nick Reddingius nredding at BBN.COM
Wed Oct 20 18:23:07 EDT 1993

The problem with "empty" holes is one with which we have had a few
bouts, too.  In one of our applications we generate contours which
may have holes in them; not doughnuts, but rather weird shapes that
long more like riparean buffers with a bulge here and there, which
may have a center where the agent being mapped is not present.  We
ultimately need a raster file, but the simulation program calculates
a vector file.  We solved this problem by assigning the inside, empty
polygon a class that was outside the range of "permissible" values,
then create the raster file, and finally reclass the map to convert
the "illegal" class for the inside "polygon" to zero.  Hokey, but it

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