From 7a8a622b5db1ec45d0dfe3b77b8e97fa1a1c62a1 Mon Sep 17 00:00:00 2001
From: James Hensman <james.hensman@gmail.com>
Date: Tue, 12 Aug 2014 11:27:50 +0100
Subject: [PATCH] strange bug in np.einsum fixed when using the _out_ argument
 (thanks T. Cohn)

---
 GPy/kern/_src/stationary.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/GPy/kern/_src/stationary.py b/GPy/kern/_src/stationary.py
index 5500bb88..5aa570a4 100644
--- a/GPy/kern/_src/stationary.py
+++ b/GPy/kern/_src/stationary.py
@@ -173,7 +173,7 @@ class Stationary(Kern):
             tmp *= 2.
             X2 = X
         ret = np.empty(X.shape, dtype=np.float64)
-        [np.einsum('ij,ij->i', tmp, X[:,q][:,None]-X2[:,q][None,:], out=ret[:,q]) for q in xrange(self.input_dim)]
+        [np.sum(tmp*(X[:,q:q+1]-X2[:,q:q+1]), axis=1, out=ret[:,q]) for q in xrange(self.input_dim)]
         ret /= self.lengthscale**2
         return ret