Observer

nsum4 neighbor-variable patch-sum-variable

Parameters:
neighbor-variable Variable the variable of the neighbor you would like to sum up
patch-sum-variable Variable the variable that should be set to the sum of the neighbors' variables

Description:
For each patch, takes the sum of neighbor-variable from the non-diagonal (N,E,S,W) neighboring patches and places it in patch-sum-variable. Variable should be a patch variable.

Examples:
nsum4 grass totalgrass adds up the value of grass in the non-diagonal patches and places it in totalgrass.

Notes:
nsum4 must be run by the observer even though it affects patches.

Related Commands:
diffuse diffuse4 nsum