MATLAB: Accumarray error: Index into matrix must be positive

Question

G=[0 1 ; 0 2 ; 1 2];
adj=accumarray(G,1,[],[],0,true); 
 error: Index into matrix must be positive.

Answer 1

What I do in situations such as yours is to add 1 to the minimum value (here 0) of the index array:

G=[0 1 ; 0 2 ; 1 2];
adj=accumarray(G+1,1,[],[],0,true);

That solves the immediate problem. You can make adjustments in other parts of your code afterwards.