[GRASSLIST:1660] A problem in using r.mapcalc

temiz temiz at deprem.gov.tr
Tue Nov 4 04:11:16 EST 2003


I encountered a problem in using r.mapcalc.
I try to create a new map using atan function from two maps that
comprise sin and cosine values in radian.

I used this expression :
r.mapcalc dene='atan(cosine_map*180/3.14,sine_map*180/3.14)'
But it only gives 45 and 225 values.
When I check this formula with known values. It gives correct
for example r.mapcalc dene='atan(0.838670*180/3.14,0.544639*180/3.14)'
it gives correct value: 33

Does anyone have any idea ?

Ahmet Temiz
General Directory of Disaster Affairs

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