code: def get_map_values(self, lons, lats, ibin=None):
          
          theta = np.pi / 2. - np.radians(lats)
          phi = np.radians(lons)
  
          pix = hp.ang2pix(self.hpx.nside, theta, phi, nest=self.hpx.nest)
  
          if self.data.ndim == 2:
              return self.data[:, pix] if ibin is None else self.data[ibin, pix]
          else:
              return self.data[pix]
docs: Return the indices in the flat array corresponding to a set of coordinates
  
          Parameters
          ----------
          lons  : array-like
             'Longitudes' (RA or GLON)
  
          lats  : array-like
             'Latitidues' (DEC or GLAT)
  
          ibin : int or array-like
             Extract data only for a given energy bin.  None -> extract data for all bins
  
          Returns
          ----------
          vals : numpy.ndarray((n))
             Values of pixels in the flattened map, np.nan used to flag
             coords outside of map