NumPHP\Core\NumArray::set PHP Method

    public function set()
    {
        $args = func_get_args();
        if (!count($args)) {
            throw new MissingArgumentException("No arguments given");
        }
        $subArray = array_pop($args);
        if ($subArray instanceof NumArray) {
            $subArray = $subArray->getData();
        }
        $this->data = Set::setSubArray($this->data, $subArray, $args);
        $this->flushCache();
        return $this;
    }

 /**
  * @param NumArray $matrix
  * @param NumArray $vector
  * @return array
  */
 protected static function gaussianEliminationPivoting(NumArray $matrix, NumArray $vector)
 {
     $shape = $matrix->getShape();
     for ($i = 0; $i < $shape[0]; $i++) {
         // find pivo element
         $max = abs($matrix->get($i, $i)->getData());
         $maxIndex = $i;
         for ($j = $i + 1; $j < $shape[0]; $j++) {
             $abs = abs($matrix->get($j, $i)->getData());
             if ($abs > $max) {
                 $max = $abs;
                 $maxIndex = $j;
             }
         }
         // pivoting
         if ($maxIndex !== $i) {
             // change maxIndex row with i row in $matrix
             $temp = $matrix->get($i);
             $matrix->set($i, $matrix->get($maxIndex));
             $matrix->set($maxIndex, $temp);
             // change maxIndex row with i row in $vector
             $temp = $vector->get($i);
             $vector->set($i, $vector->get($maxIndex));
             $vector->set($maxIndex, $temp);
         }
         for ($j = $i + 1; $j < $shape[0]; $j++) {
             $fac = -$matrix->get($j, $i)->getData() / $matrix->get($i, $i)->getData();
             $matrix->set($j, $matrix->get($j)->add($matrix->get($i)->dot($fac)));
             $vector->set($j, $vector->get($j)->add($vector->get($i)->dot($fac)));
         }
     }
     return ['M' => $matrix, 'b' => $vector];
 }