How to create Matrix using for loop and if-else statement in MATLAB?

Question:

How to create Matrix using for loop and if-else statement in MATLAB?

Answer:

Let's create a square matrix of size \(5 \times 5\) in MATLAB with diagonal element a scalar (say 3) and all other elements (say -1).

Here is the MATLAB script:

m = 5;
n = 5;
% A is matrix of m rows and n columns
A = zeros(m,n);
for i = 1:m
    for j = 1:n
        if i == j
            A(i,j) = 3;
        else
            A(i,j) = -1;
        end
    end
end
disp(A)
disp('We are Done!!!')

OUTPUT

A =
     3    -1    -1    -1    -1
    -1     3    -1    -1    -1
    -1    -1     3    -1    -1
    -1    -1    -1     3    -1
    -1    -1    -1    -1     3

We are Done!!!

YouTube Tutorial for Creating Matrix in MATLAB