public function determinant(Matrix $matrix)
{
$sum = 0;
if ($matrix->getMatrixSizeA() == 1) {
return $this->determinant1x1();
} else {
if ($matrix->getMatrixSizeA() == 2) {
return $this->determinant2x2();
} else {
if ($matrix->getMatrixSizeA() == 3) {
return $this->determinant3x3();
}
}
}
for ($i = 0; $i < $matrix->getMatrixSizeA(); $i++) {
$smaller = [];
for ($a = 1; $a < $matrix->getMatrixSizeA(); $a++) {
for ($b = 0; $b < $matrix->getMatrixSizeA(); $b++) {
if ($b < $i) {
$smaller[$a - 1][$b] = $matrix[$a][$b];
} else {
if ($b > $i) {
$smaller[$a - 1][$b - 1] = $matrix->getMatrix()[$a][$b];
}
}
}
}
$sum += $i % 2 == 0 ? 1 : -1 * $matrix->getMatrix()[0][$i] * $this->determinant(new Matrix($smaller));
}
return $sum;
}
private function mult2(Matrix $a = NULL, Matrix $b = NULL)
{
$n = $a->getMatrixSizeA();
$c = [];
if ($n == 1) {
$c[1][1] = $a->getMatrix()[1][1] * $b->getMatrix()[1][1];
} else {
$c[1][1] = $this->mult($a->getMatrix()[1][1], $b->getMatrix()[1][1]) + $this->mult($a->getMatrix()[1][2], $b->getMatrix()[2][1]);
$c[1][2] = $this->mult($a->getMatrix()[1][1], $b->getMatrix()[1][2]) + $this->mult($a->getMatrix()[1][2], $b->getMatrix()[2][2]);
$c[2][1] = $this->mult($a->getMatrix()[2][1], $b->getMatrix()[1][1]) + $this->mult($a->getMatrix()[2][2], $b->getMatrix()[2][1]);
$c[2][2] = $this->mult($a->getMatrix()[2][1], $b->getMatrix()[1][2]) + $this->mult($a->getMatrix()[2][2], $b->getMatrix()[2][2]);
}
return $c;
}
public function isSameSize(Matrix $matrix = NULL)
{
if ($matrix == NULL) {
throw new NullPointerException();
}
if ($this->getMatrixSizeA() != $matrix->getMatrixSizeA()) {
return FALSE;
}
foreach ($this->getMatrix() as $k => $v) {
if (count($matrix->getMatrix()[$k]) != count($this->getMatrix()[$k])) {
return FALSE;
}
}
return TRUE;
}
public function mult(Matrix $a = NULL, Matrix $b = NULL)
{
$newMatrix = [];
if ($a->getMatrixSizeA() != $b->getMatrixSizeB()) {
throw new IllegalArgumentException();
}
for ($i = 0; $i < $a->getMatrixSizeA(); $i++) {
for ($j = 0; $j < $b->getMatrixSizeB(); $j++) {
for ($k = 0; $k < $a->getMatrixSizeB(); $k++) {
$newMatrix[$i][$j] += $a->getMatrix()[$i][$k] * $b->getMatrix()[$k][$j];
}
}
}
return new Matrix($newMatrix);
}
public function sub(Matrix $a = NULL, Matrix $b = NULL)
{
if ($a == NULL || $b == NULL) {
throw new NullPointerException();
}
$matrix = [];
for ($i = 0; $i < $a->getMatrixSizeA(); $i++) {
for ($j = 0; $j < $a->getMatrixSizeA(); $j++) {
$matrix[$i][$j] = $a->getMatrix()[$i][$j] - $b->getMatrix()[$i][$j];
}
}
return new Matrix($matrix);
}
