Revert einsum optimization

Minghui Liu · minghui-liu · commit d698126fba74 · 2017-08-13T00:52:50.000-04:00
diff --git a/sklearn/gaussian_process/gpr.py b/sklearn/gaussian_process/gpr.py
@@ -332,8 +332,7 @@ def predict(self, X, return_std=False, return_cov=False):
 
                 # Compute variance of predictive distribution
                 y_var = self.kernel_.diag(X)
-                sum1 = np.dot(K_trans, self._K_inv).T
-                y_var -= np.einsum("ki,ik->k", K_trans, sum1)
+                y_var -= np.einsum("ij,ij->i", np.dot(K_trans, self._K_inv), K_trans)
 
                 # Check if any of the variances is negative because of
                 # numerical issues. If yes: set the variance to 0.
