def user_to_device_distance(self, dx, dy):
        """Transform a distance vector from user space to device space.
        This method is similar to :meth:`Context.user_to_device`
        except that the translation components of the CTM
        will be ignored when transforming ``(dx, dy)``.

        :param dx: X component of a distance vector.
        :param dy: Y component of a distance vector.
        :type x: float
        :type y: float
        :returns: A ``(device_dx, device_dy)`` tuple of floats.

        """
        xy = ffi.new('double[2]', [dx, dy])
        cairo.cairo_user_to_device_distance(self._pointer, xy + 0, xy + 1)
        self._check_status()
        return tuple(xy)
Transform a distance vector from user space to device space.
        This method is similar to :meth:`Context.user_to_device`
        except that the translation components of the CTM
        will be ignored when transforming ``(dx, dy)``.

        :param dx: X component of a distance vector.
        :param dy: Y component of a distance vector.
        :type x: float
        :type y: float
        :returns: A ``(device_dx, device_dy)`` tuple of floats.