'Compute positive associations between visible and hidden units.
:param visible: visible units
:param hidden_probs: hidden units probabilities
:param hidden_states: hidden units states
:return: positive association = dot(visible.T, hidden)'

def compute_positive_association(self, visible, hidden_probs, hidden_states):

    if (self.visible_unit_type == 'bin'):
        positive = tf.matmul(tf.transpose(visible), hidden_states)
    elif (self.visible_unit_type == 'gauss'):
        positive = tf.matmul(tf.transpose(visible), hidden_probs)
    else:
        positive = None
    return positive
