how to correct this index error ?

su=4;
sv=4;
fh=[1 2 3 4; 2 3 4 5 ; 5 6 7 8 ; 1 2 3 5];
for i=-4:4
    for j=-4:4   
        a(i,j)=1;
        for u=1:su-2
            for v=1:sv
                 if (fh(u,v)==i && fh(u+1,v)==j)
                     dell=1;
                 else
                     dell=0;
                 end 
                 a(i,j)=a(i,j)+dell;
            end
        end
    end
end

..when i run this code i got this error..

??? Attempted to access a(-4,-4); index must be a positive integer or logical.
Error in ==> testit at 6
      a(i,j)=1;

[Andrei Bobrov]

see this answer

[Jan]

Please, prasana, use meaningful tags. Almost all questions in this forum concern Matlab code.

Answer 1

[Jan]

You are working with Matlab for at least 3 month. It is time to read the Getting Started chapters to find out, that indices must be positive integers. Therefore you cannot access the element a(-4, -4). This seems to be a trivial solution:

for i = 1:9
  for j = 1:9