diff --git a/quantecon/markov/ddp.py b/quantecon/markov/ddp.py index 1c0b998e0..a5a308f19 100644 --- a/quantecon/markov/ddp.py +++ b/quantecon/markov/ddp.py @@ -417,7 +417,8 @@ def s_wise_max(vals, out=None, out_argmax=None): # Linear equation solver to be used in evaluate_policy if self._sparse: - self._lineq_solve = sp.linalg.spsolve + import scipy.sparse.linalg + self._lineq_solve = scipy.sparse.linalg.spsolve self._I = sp.identity(self.num_states, format='csr') else: self._lineq_solve = np.linalg.solve