src/Maths/Algebra/Matrix.php
public function seekXY($index)
    {
        $parts = explode(self::XY_SEPARATOR, $index);
        if (false==strpos($index, self::XY_SEPARATOR) || count($parts)>2) {
            throw new InvalidArgumentException(
                sprintf("Cell index of a matrix must be set as 'x%sy'", self::XY_SEPARATOR)
            );
        }
        try {
            $this->seekX($parts[0]);
            $this->seekY($parts[1]);
        } catch (OutOfRangeException $e) {
            throw $e;
        }
        return $this;
    }
public function seekXY($index)
    {
        $parts = explode(self::XY_SEPARATOR, $index);
        if (false==strpos($index, self::XY_SEPARATOR) || count($parts)>2) {
            throw new InvalidArgumentException(
                sprintf("Cell index of a matrix must be set as 'x%sy'", self::XY_SEPARATOR)
            );
        }
        try {
            $this->seekX($parts[0]);
            $this->seekY($parts[1]);
        } catch (OutOfRangeException $e) {
            throw $e;
        }
        return $this;
    }
Seek to index for `x,y` (cell)

@param   string  $index  The index to go to, constructed like `x,y`
@return  $this
@throws  OutOfRangeException if the `x` index is out of range
@throws  OutOfRangeException if the `y` index is out of range
@throws  InvalidArgumentException if the argument is malformed