Question

How to check if a matrix is symmetric (square matrix that is equal to its transpose) in PHP

Answer 1

function checkSymmetric($matrix) {
    $rows = count($matrix);
    $cols = count($matrix[0]);
    
    if ($rows != $cols) {
        return false;
    }
    
    for ($i = 0; $i < $rows; $i++) {
        for ($j = 0; $j < $cols; $j++) {
            if ($matrix[$i][$j] != $matrix[$j][$i]) {
                return false;
            }
        }
    }
    
    return true;
}
        
$matrix = array(
            array(1, 5, 2, 4), 
            array(5, 6, 3, 7), 
            array(2, 3, 9, 0), 
            array(4, 7, 0, 8)
        );

if (checkSymmetric($matrix)) {
    echo "yes";
}
else {
    echo "no";
}



/*
run:

yes

*/

 

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