def bilinear_interpolation_weights(self, lon, lat):
        """
        Get the four neighbours for each (lon, lat) position and the weight
        associated with each one for bilinear interpolation.

        Parameters
        ----------
        lon, lat : :class:`~astropy.units.Quantity`
            The longitude and latitude values as
            :class:`~astropy.units.Quantity` instances with angle units.

        Returns
        -------
        indices : `~numpy.ndarray`
            2-D array with shape (4, N) giving the four indices to use for the
            interpolation
        weights : `~numpy.ndarray`
            2-D array with shape (4, N) giving the four weights to use for the
            interpolation
        """
        return bilinear_interpolation_weights(lon, lat, self.nside, order=self.order)
Get the four neighbours for each (lon, lat) position and the weight
        associated with each one for bilinear interpolation.

        Parameters
        ----------
        lon, lat : :class:`~astropy.units.Quantity`
            The longitude and latitude values as
            :class:`~astropy.units.Quantity` instances with angle units.

        Returns
        -------
        indices : `~numpy.ndarray`
            2-D array with shape (4, N) giving the four indices to use for the
            interpolation
        weights : `~numpy.ndarray`
            2-D array with shape (4, N) giving the four weights to use for the
            interpolation