bayesian_nn.py 文件源码

def evaluation(self, X_test, y_test):
        # normalization
        X_test = self.normalization(X_test)

        # average over the output
        pred_y_test = np.zeros([self.M, len(y_test)])
        prob = np.zeros([self.M, len(y_test)])

        '''
            Since we have M particles, we use a Bayesian view to calculate rmse and log-likelihood
        '''
        for i in range(self.M):
            w1, b1, w2, b2, loggamma, loglambda = self.unpack_weights(self.theta[i, :])
            pred_y_test[i, :] = self.nn_predict(X_test, w1, b1, w2, b2) * self.std_y_train + self.mean_y_train
            prob[i, :] = np.sqrt(np.exp(loggamma)) /np.sqrt(2*np.pi) * np.exp( -1 * (np.power(pred_y_test[i, :] - y_test, 2) / 2) * np.exp(loggamma) )
        pred = np.mean(pred_y_test, axis=0)

        # evaluation
        svgd_rmse = np.sqrt(np.mean((pred - y_test)**2))
        svgd_ll = np.mean(np.log(np.mean(prob, axis = 0)))

        return (svgd_rmse, svgd_ll)