/**
* Subtract matrix2 from matrix object on which this method is called
*
* @param Matrix $matrix2
*
* @return Matrix Note that original matrix is left unchanged
* @throws \DomainException
* @throws \InvalidArgumentException
*/
public function subtract(Matrix $matrix2)
{
if ($this->rows !== $matrix2->numRows() || $this->columns !== $matrix2->numColumns()) {
throw new \DomainException('Matrices are not the same size!');
}
$newMatrix = [];
foreach ($this->mainMatrix as $i => $row) {
foreach ($row as $j => $column) {
$newMatrix[$i][$j] = $column - $matrix2->getElementAt($i, $j);
}
}
return new Matrix($newMatrix);
}