measuring area

[Joe Leone]

Hi all,
        I have a situation in which I am trying to extend (grow) the area of a 
patch in a particular direction, depending on the ajacent cell. I want the patc
h to grow only untill it gets to a specified size ( say 20 Hectares). The troub
le I have is stopping the growth.  
I have managed to get the patch to grow by identifying potential growth areas a
nd runing the script below

I would appreciate any suggestion.

Thanks Joe 



raster map test.g has three categories


cat value       cat label
0               potenial growth
5               non growth
999             patch value


#!/bin/csh -f
# r.mapcalc script to grow remnant aeras in suitable soil types.
 
@ i=1
@ num=10
echo $i
echo "this will run through "$num, "loops   "
d.erase
g.copy rast=test.g,output
#echo " now using "output.$i--
while ($i <= $num)
 
r.mapcalc output.$i = 'if(output,output, eval(if(output[0,-1]==999|| output[0,1
]==999||output[-1,0]==999||output[1,0]==999,999)))'
 
g.copy rast=output.$i,output
@ i++
echo $i
end