code: def containing_triangle(self, lons, lats):
          
          p = self._permutation
          pts = np.array(lonlat2xyz(lons,lats)).T
  
          sorted_simplices = np.sort(self._simplices, axis=1)
  
          triangles = []
          for pt in pts:
              t = _stripack.trfind(3, pt, self._x, self._y, self._z, self.lst, self.lptr, self.lend )
              tri = np.sort(t[3:6]) - 1
  
              triangles.append(np.where(np.all(p[sorted_simplices]==p[tri], axis=1))[0])
  
          return np.array(triangles).reshape(-1)
docs: Returns indices of the triangles containing lons / lats.
  
          Parameters
          ----------
           lons : float / array of floats, shape (l,)
              longitudinal coordinate(s) on the sphere
           lats : float / array of floats, shape (l,)
              latitudinal coordinate(s) on the sphere
  
          Returns
          -------
           tri_indices : array of ints, shape (l,)
  
  
          Notes
          -----
            The simplices are found as spherical.sTriangulation.simplices[tri_indices]