src/Maths/Algebra/Matrix.php
public function keyXY($integer = false)
    {
        if ($integer==true) {
            return $this->keyInt();
        }
        return $this->x.self::XY_SEPARATOR.$this->y;
    }
public function keyXY($integer = false)
    {
        if ($integer==true) {
            return $this->keyInt();
        }
        return $this->x.self::XY_SEPARATOR.$this->y;
    }
Get current `x,y` index (cell)

@param   bool    $integer    Return an integer index (0 based) or a positional one (1 based)
@return  string|null