MathPHP\LinearAlgebra\Matrix::kroneckerProduct PHP Method

    public function kroneckerProduct(Matrix $B) : Matrix
    {
        // Compute each element of the block matrix
        $arrays = [];
        for ($m = 0; $m < $this->m; $m++) {
            $row = [];
            for ($n = 0; $n < $this->n; $n++) {
                $R = [];
                for ($p = 0; $p < $B->getM(); $p++) {
                    for ($q = 0; $q < $B->getN(); $q++) {
                        $R[$p][$q] = $this->A[$m][$n] * $B[$p][$q];
                    }
                }
                $row[] = new Matrix($R);
            }
            $arrays[] = $row;
        }
        // Augment each aᵢ₁ to aᵢn block
        $matrices = [];
        foreach ($arrays as $row) {
            $initial_matrix = array_shift($row);
            $matrices[] = array_reduce($row, function ($augmented_matrix, $matrix) {
                return $augmented_matrix->augment($matrix);
            }, $initial_matrix);
        }
        // Augment below each row block a₁ to am
        $initial_matrix = array_shift($matrices);
        $A⊗B = array_reduce($matrices, function ($augmented_matrix, $matrix) {
            return $augmented_matrix->augmentBelow($matrix);
        }, $initial_matrix);
        return $A⊗B;
    }