[GRASS5] r.mapcalc x() with no layer in expression

Dan Jacobson jidanni at dman.ddts.net
Sun Nov 10 00:11:11 EST 2002


Does the r.mapcalc man page and tutorial assume that one has the name
of an input map layer in some other part of the equation and thus
never mentions what happens if you don't, but still want to use x(),
y()?

Is this what one would be forced to do in that case?
(e.g. when making a layer with values being the distance from home:)
out=nantou.dist xc=235577 yc=2675353 ;\
r.mapcalc "${out?} = nantou - nantou + sqrt((x() - ${xc?})^2 + (y() - ${yc?})^2)"
[nantou - nantou: a noop just to get the layer nantou involved in the
expression.]

So: please update the docs to mention what to do.
-- 
http://jidanni.org/ Taiwan(04)25854780





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