Merge pull request scikit-learn#5049 from amueller/gp_reshape_fixes

[MRG + 1] fix shape of thetaL, thetaU, theta0 in gp

Author: GaelVaroquaux

sklearn/gaussian_process/gaussian_process.py

@@ -718,17 +718,16 @@ def minus_reduced_likelihood_function(log10t):
                 else:
                     # Generate a random starting point log10-uniformly
                     # distributed between bounds
-                    log10theta0 = np.log10(self.thetaL) \
-                        + self.random_state.rand(self.theta0.size).reshape(
-                            self.theta0.shape) * np.log10(self.thetaU
-                                                          / self.thetaL)
+                    log10theta0 = (np.log10(self.thetaL)
+                                   + self.random_state.rand(*self.theta0.shape)
+                                   * np.log10(self.thetaU / self.thetaL))
                     theta0 = 10. ** log10theta0
 
                 # Run Cobyla
                 try:
                     log10_optimal_theta = \
                         optimize.fmin_cobyla(minus_reduced_likelihood_function,
-                                             np.log10(theta0), constraints,
+                                             np.log10(theta0).ravel(), constraints,
                                              iprint=0)
                 except ValueError as ve:
                     print("Optimization failed. Try increasing the ``nugget``")