src/Maths/Algebra/Matrix.php
public function next()
    {
        if ($this->getWalkFlag() & self::WALK_X) {
            return $this->nextX();
        } elseif ($this->getWalkFlag() & self::WALK_Y) {
            return $this->nextY();
        } else {
            return $this->nextXY();
        }
    }
public function next()
    {
        if ($this->getWalkFlag() & self::WALK_X) {
            return $this->nextX();
        } elseif ($this->getWalkFlag() & self::WALK_Y) {
            return $this->nextY();
        } else {
            return $this->nextXY();
        }
    }
Go to next index according to matrix's flag value

@return  $this
@see     self::nextX()
@see     self::nextY()
@see     self::nextXY()