+ if self._basis_normalizers is not None:
+ # Must be a matrix class?
+ # WARNING/TODO: this whole mess is mis-designed.
+ n = self.natural_basis_space().nrows()
+ field = self.base_ring().base_ring() # yeeeeaaaahhh
+ J = self.__class__(n, field, False)
+ (_,x,_,_) = J._charpoly_matrix_system()
+ p = J._charpoly_coeff(i)
+ # p might be missing some vars, have to substitute "optionally"
+ pairs = zip(x.base_ring().gens(), self._basis_normalizers)
+ substitutions = { v: v*c for (v,c) in pairs }
+ return p.subs(substitutions)
+