def query(self, coords):
        """
        Args:
            coords (`astropy.coordinates.SkyCoord`): The coordinates to query.

        Returns:
            A float array of the value of the map at the given coordinates. The
            shape of the output is the same as the shape of the coordinates
            stored by `coords`.
        """
        pix_idx = coord2healpix(coords, self._frame,
                                self._nside, nest=self._nest)
        return self._pix_val[pix_idx]