code: def get_element_coors(self, ig=None):
          
          cc = self.coors
          n_ep_max = self.n_e_ps.max()
  
          coors = nm.empty((self.n_el, n_ep_max, self.dim), dtype=cc.dtype)
          for ig, conn in enumerate(self.conns):
              i1, i2 = self.el_offsets[ig], self.el_offsets[ig + 1]
              coors[i1:i2, :conn.shape[1], :] = cc[conn]
  
          return coors
docs: Get the coordinates of vertices elements in group `ig`.
  
          Parameters
          ----------
          ig : int, optional
              The element group. If None, the coordinates for all groups
              are returned, filled with zeros at places of missing
              vertices, i.e. where elements having less then the full number
              of vertices (`n_ep_max`) are.
  
          Returns
          -------
          coors : array
              The coordinates in an array of shape `(n_el, n_ep_max, dim)`.