From ac3b6aba869c077198208c42dfaf517f54759058 Mon Sep 17 00:00:00 2001
From: Daisuke Oyama <oyama@e.u-tokyo.ac.jp>
Date: Fri, 12 Apr 2019 15:00:25 +0900
Subject: [PATCH] FIX: Import scipy.sparse.linalg

Fix #481
---
 quantecon/markov/ddp.py | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

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