Addition of Two Matrices in PHP

Given two matrices mat1 and mat2, the task is to find the sum of both matrices. Matrix addition is possible only when both matrix’s dimensions are the same. If both matrices have different dimensions then addition will not be possible.

Sum of Two Matrices using for Loop

First, we declare two matrices, matrix1 and matrix2. Next, we check both matrix dimension, if both matrix dimension is same then we proceed for sum of matrices, otherwise display an error message. To add both matrices, we use for loop. For loop iterate each matrix elements one by one, and perform sum on the elements.

Example: Sum of two matrices using for Loop in PHP.

PHP

<?php

function sumTwoMatrices($mat1, $mat2) {
    $rows = count($mat1);
    $columns = count($mat1[0]);

    // Sum Matrix Initialize with Zeros
    $sum = array();
    for ($i = 0; $i < $rows; $i++) {
        for ($j = 0; $j < $columns; $j++) {
            $sum[$i][$j] = 0;
        }
    }

    // Matrix Addition
    for ($i = 0; $i < $rows; $i++) {
        for ($j = 0; $j < $columns; $j++) {
            $sum[$i][$j] = $mat1[$i][$j] + $mat2[$i][$j];
        }
    }

    return $sum;
}

// First Matrix
$matrix1 = array(
    array(26, 14, 31),
    array(41, 61, 11),
    array(14, 12, 19)
);

// Second Matrix
$matrix2 = array(
    array(11, 8, 27),
    array(21, 15, 25),
    array(22, 15, 21)
);

// Get the first Matrix dimension
$rows1 = count($matrix1);
$columns1 = count($matrix1[0]);

// Get the second Matrix dimension
$rows2 = count($matrix2);
$columns2 = count($matrix2[0]);

// Check both matrix dimension is equal or not
if($rows1 != $rows2 || $columns1 != $columns2) {
    echo "Matrix dimension not Equal. Sum not possible";
}
else {

    // Sum of Matrices
    $sum = sumTwoMatrices($matrix1, $matrix2);

    // Print the Sum Matrix
    foreach ($sum as $row) {
        echo implode("\t", $row) . "\n";
    }
}

?>

Output

37    22    58
62    76    36
36    27    40