def ipix_to_xypix(self, ipix, colwise=False):
        """Return array multi-dimensional pixel indices from flattened index.

        Parameters
        ----------
        colwise : bool
            Use column-wise pixel indexing.
        """
        return np.unravel_index(ipix, self.npix,
                                order='F' if colwise else 'C')
Return array multi-dimensional pixel indices from flattened index.

        Parameters
        ----------
        colwise : bool
            Use column-wise pixel indexing.