Matrix multiplication in php

Question

Although the order of matrices should be fine, the following code throws back the exception. It might be a tiny thing I\'m not being able to notice, but can\'t figure it out.

Answer 1

You're specifying your test matrices wrong, in two ways:

1. The arrays aren't two-dimensional (that is, arrays of arrays of numbers).
2. Even if you wrapped another array( ) around them, the condition that the width of the first matrix be equal to the height of the second matrix doesn't hold with [5 1] and [1 5], which are both 2 wide and 1 high.

What you need is something like

$mat1 = array(array(5,1));
$mat2 = array(array(1),array(5));