diff --git a/GPy/models/sparse_GP_regression.py b/GPy/models/sparse_GP_regression.py index f34819dc..0f0b0569 100644 --- a/GPy/models/sparse_GP_regression.py +++ b/GPy/models/sparse_GP_regression.py @@ -87,11 +87,11 @@ class sparse_GP_regression(GP_regression): self.psi1V = np.dot(self.psi1, self.V) self.psi1VVpsi1 = np.dot(self.psi1V, self.psi1V.T) self.Kmmi, self.Lm, self.Lmi, self.Kmm_logdet = pdinv(self.Kmm) - self.A = mdot(self.Lmi, self.psi2, self.Lmi.T) - self.B = np.eye(self.M) + self.beta * self.A + self.A = mdot(self.Lmi, self.beta*self.psi2, self.Lmi.T) + self.B = np.eye(self.M) + self.A self.Bi, self.LB, self.LBi, self.B_logdet = pdinv(self.B) self.LLambdai = np.dot(self.LBi, self.Lmi) - self.trace_K = self.psi0 - np.trace(self.A) + self.trace_K = self.psi0 - np.trace(self.A)/self.beta self.LBL_inv = mdot(self.Lmi.T, self.Bi, self.Lmi) self.C = mdot(self.LLambdai, self.psi1V) self.G = mdot(self.LBL_inv, self.psi1VVpsi1, self.LBL_inv.T) @@ -102,7 +102,7 @@ class sparse_GP_regression(GP_regression): self.dL_dpsi2 = - 0.5 * self.beta * (self.D*(self.LBL_inv - self.Kmmi) + self.G) # Compute dL_dKmm - self.dL_dKmm = -0.5 * self.beta * self.D * mdot(self.Lmi.T, self.A, self.Lmi) # dB + self.dL_dKmm = -0.5 * self.D * mdot(self.Lmi.T, self.A, self.Lmi) # dB self.dL_dKmm += -0.5 * self.D * (- self.LBL_inv - 2.*self.beta*mdot(self.LBL_inv, self.psi2, self.Kmmi) + self.Kmmi) # dC self.dL_dKmm += np.dot(np.dot(self.G,self.beta*self.psi2) - np.dot(self.LBL_inv, self.psi1VVpsi1), self.Kmmi) + 0.5*self.G # dE @@ -126,15 +126,14 @@ class sparse_GP_regression(GP_regression): def dL_dbeta(self): """ Compute the gradient of the log likelihood wrt beta. - TODO: suport heteroscedatic noise """ - + #TODO: suport heteroscedatic noise dA_dbeta = 0.5 * self.N*self.D/self.beta dB_dbeta = - 0.5 * self.D * self.trace_K - dC_dbeta = - 0.5 * self.D * np.sum(self.Bi*self.A) + dC_dbeta = - 0.5 * self.D * np.sum(self.Bi*self.A)/self.beta dD_dbeta = - 0.5 * self.trYYT tmp = mdot(self.LBi.T, self.LLambdai, self.psi1V) - dE_dbeta = np.sum(np.square(self.C))/self.beta - 0.5 * np.sum(self.A * np.dot(tmp, tmp.T)) + dE_dbeta = (np.sum(np.square(self.C)) - 0.5 * np.sum(self.A * np.dot(tmp, tmp.T)))/self.beta return np.squeeze(dA_dbeta + dB_dbeta + dC_dbeta + dD_dbeta + dE_dbeta) diff --git a/GPy/models/uncollapsed_sparse_GP.py b/GPy/models/uncollapsed_sparse_GP.py index 8761aac4..15f52612 100644 --- a/GPy/models/uncollapsed_sparse_GP.py +++ b/GPy/models/uncollapsed_sparse_GP.py @@ -39,7 +39,7 @@ class uncollapsed_sparse_GP(sparse_GP_regression): self.M = Z.shape[0] else: self.M = M - q_u = np.hstack((np.ones(self.M*self.D),-0.5*np.eye(self.M).flatten())) + q_u = np.hstack((np.zeros(self.M*self.D),-0.5*np.eye(self.M).flatten())) self.set_vb_param(q_u) sparse_GP_regression.__init__(self, X, Y, M=M,*args, **kwargs) @@ -49,8 +49,8 @@ class uncollapsed_sparse_GP(sparse_GP_regression): self.psi1V = np.dot(self.psi1, self.V) self.psi1VVpsi1 = np.dot(self.psi1V, self.psi1V.T) self.Kmmi, self.Lm, self.Lmi, self.Kmm_logdet = pdinv(self.Kmm) - self.A = self.beta * mdot(self.Lmi, self.psi2, self.Lmi.T) - self.B = np.eye(self.M) * self.A + self.A = mdot(self.Lmi, self.beta*self.psi2, self.Lmi.T) + self.B = np.eye(self.M) + self.A self.Lambda = mdot(self.Lmi.T,self.B,self.Lmi) self.trace_K = self.psi0 - np.trace(self.A)/self.beta self.projected_mean = mdot(self.psi1.T,self.Kmmi,self.q_u_expectation[0]) @@ -70,10 +70,10 @@ class uncollapsed_sparse_GP(sparse_GP_regression): """ A = -0.5*self.N*self.D*(np.log(2.*np.pi) - np.log(self.beta)) B = -0.5*self.beta*self.D*self.trace_K - C = -0.5*self.D *(self.Kmm_logdet + np.sum(self.Lambda * self.q_u_expectation[1]) + self.M/2.) + C = -0.5*self.D *(self.Kmm_logdet + np.sum(self.Lambda * self.q_u_expectation[1]) - self.M*self.D) D = -0.5*self.beta*self.trYYT E = np.sum(np.dot(self.V.T,self.projected_mean)) - return A+B+C+D+E + return A+B#+C+D+E def dL_dbeta(self): """