docs: def _reshape_m_vecs(self):
          """return list of arrays, each array represents a different n mode"""
          
          lst = []
          for n in xrange(0, self.nmax + 1):
              mlst = []
              if n <= self.mmax:
                  nn = n
              else:
                  nn = self.mmax            
              for m in xrange(-nn, nn + 1):
                  mlst.append(self.__getitem__((n, m)))
              lst.append(mlst)
          return lst