src/Maths/Algebra/Matrix.php
public function setX($index, array $value)
    {
        try {
            $this->seekX($index);
            $this->data[$this->keyX(true)] = $value;
        } catch (OutOfRangeException $e) {
            throw $e;
        }
        return $this;
    }
public function setX($index, array $value)
    {
        try {
            $this->seekX($index);
            $this->data[$this->keyX(true)] = $value;
        } catch (OutOfRangeException $e) {
            throw $e;
        }
        return $this;
    }
Set `x` value (line) by index

@param   string|int  $index
@param   array       $value
@return  $this
@throws  OutOfRangeException if the index is out of range