how to creat a Vectorization instead of a Double Loop

for i = 1:n
    for j = 1:m
        if A(i,j)==1
            output = myfcn(A,i,j);
            if output==0
                    A(i,j) = 2;
                    t = t+1;
            elseif output==1
                    A(i,j) = 3;
                    t = t+1;
            end
        end
    end
end

Answer 1

[Jan]

The most important part is "myfcn", which is not shown yet.

Can it be called with an array as input? What does it reply? Only 0 and 1 or are other outputs possible?

A leaner version might be:

for j = 1:m     % Swap loops: Columnwise processing is faster
   for i = 1:n
        if A(i,j) == 1
            A(i,j) = 2 + myfcn(A,i,j);
            t = t+1;
        end
    end
end