Not able to obtain Predicted values in Bayesian neural network

I am trying to construct Bayesian neural network to solve my problem, with reference to the PyMC3 tutorial case "Variational Inference: Bayesian Neural Networks". I am using Continuous dependent variable but not able to obtain the predicted values in Bayesian neural network.

Code used for construction of neural network :

def construct_nn(ann_input, ann_output):
    n_hidden = 5

    # Initialize random weights between each layer
    init_1 = np.random.randn(X.shape[1], n_hidden).astype(floatX)
    init_2 = np.random.randn(n_hidden, n_hidden).astype(floatX)
    init_out = np.random.randn(n_hidden).astype(floatX)

    with pm.Model() as neural_network:
        # Weights from input to hidden layer
        weights_in_1 = pm.Normal('w_in_1', 0, sd=1,
                                 shape=(X.shape[1], n_hidden),
                                 testval=init_1)

        # Weights from 1st to 2nd layer
        weights_1_2 = pm.Normal('w_1_2', 0, sd=1,
                                shape=(n_hidden, n_hidden),
                                testval=init_2)

        # Weights from hidden layer to output
        weights_2_out = pm.Normal('w_2_out', 0, sd=1,
                                  shape=(n_hidden,),
                                  testval=init_out)

        # Build neural-network using tanh activation function
        act_1 = pm.math.tanh(pm.math.dot(ann_input,
                                         weights_in_1))
        act_2 = pm.math.tanh(pm.math.dot(act_1,
                                         weights_1_2))
        act_out = pm.math.sigmoid(pm.math.dot(act_2,
                                              weights_2_out))

        out = pm.Normal('out',mu=act_out, observed=ann_output)

    return neural_network

ann_input = theano.shared(X_train)
ann_output = theano.shared(Y_train)
neural_network = construct_nn(ann_input, ann_output)

from pymc3.theanof import set_tt_rng, MRG_RandomStreams
set_tt_rng(MRG_RandomStreams(42))

#Fitting the model
with neural_network:
    inference = pm.ADVI()
    approx = pm.fit(n=3000, method=inference)

trace = approx.sample(draws=5000)

After this step, i want to obtain the predicted values for a continuous variable.

Versions and main components

PyMC3 Version: 3.5
Theano Version: 1.0.2
Python Version: 3.6
Operating system: Windows 7 Enterprise
How did you install PyMC3: (conda/pip)

pymc-devs / pymc

Not able to obtain Predicted values in Bayesian neural network #3189

Versions and main components