MATLAB: Index in position 2 exceeds array bounds (must not exceed 8)

index

I keep getting the error "Index in position 2 exceeds array bounds (must not exceed 8) with the following code. I am trying to determine whether a matrix is strictly diagonally dominant or not. The error appears on the line with sumrow=sumrow+abs(A(i,j));
This is the code. 
A = [28 -6 4 1 -2 -5 8 0; 
    -4 28 -1 4 0 4 4 6; 
    1 -6 26 -5 1 -1 -6 0; 
    1 -6 26 -5 1 -1 -6 0; 
    -5 -6 1 21 0 -3 2 2; 
    4 1 3 -3 17 0 -3 3; 
    4 -2 3 0 2 14 0 1; 
    1 2 4 3 -2 1 17 4; 
    1 3 1 3 0 -1 3 15];
rowcol=size(A);
n=rowcol(1);
 
count=0;
for i=1:1:n
    sumrow=0;
    for j=1:1:n
        if i~=j
            sumrow=sumrow+abs(A(i,j));
        end
    end
    if abs(A(i,i))>sumrow
        count=count+1;
    end
end
if count==n
    disp('Matrix is strictly diagonal dominant')
else
    disp('Matrix is NOT strictly diagonal dominant')
end
Any help with corrections will be greatly appreciated.

Best Answer

The matrix is not square, so you need to find the minimum of row and column numbers.
A = [28 -6 4 1 -2 -5 8 0; -4 28 -1 4 0 4 4 6; 1 -6 26 -5 1 -1 -6 0; 1 -6 26 -5 1 -1 -6 0; -5 -6 1 21 0 -3 2 2; 4 1 3 -3 17 0 -3 3; 4 -2 3 0 2 14 0 1; 1 2 4 3 -2 1 17 4; 1 3 1 3 0 -1 3 15];
rowcol=size(A);
n=min(size(A));
 
count=0;
for i=1:1:n
    sumrow=0;
    for j=1:1:n
        if i~=j
            sumrow=sumrow+abs(A(i,j));
        end
    end
    if abs(A(i,i))>sumrow
        count=count+1;
    end
end
if count==n
    disp('Matrix is strictly diagonal dominant')
else
    disp('Matrix is NOT strictly diagonal dominant')
end
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