MATLAB Expanding A Matrix with Zeros

matlab, matrix, vectorization

Solution

The answer is creating a matrix of zeroes, and then setting part of it to `1` using indexing:

For example:

n = 4;
p = 2;
x = zeros(n,n);
x(1:p,1:p) = 1;

If you insist on expanding, you can use:

padarray( zeros(p,p)+1 , [n-p n-p], 0, 'post')

Problem

I need a matrix of `nxn`, where the first `pxp` of it contains ones and rest are zeros. I can do it with traversing the cells, so I'm not asking a way to do it. I'm looking for "the MATLAB way" to do it, using built-in functions and avoiding loops etc. To be more clear; let `n=4 and p=2`, then the expected result is: ``` 1 1 0 0 1 1 0 0 0 0 0 0 0 0 0 0 ``` There are possibly more than one elegant solution to do it, so I will accept the answer with the shortest and most readable one. P.S. The question title looks a bit irrelevant: I put that title because my initial approach would be creating a `pxp` matrix with ones, then expanding it to `nxn` with zeros.

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