utils.py

import tensorflow as tf
import os

def create_dirs_if_not_exists(path):
    if not os.path.exists(path):
        os.makedirs(path)

def printShape(tensor):
    print(tensor.shape)


def squash(s, axis=-1, epsilon=1e-7, name=None):
    with tf.name_scope(name, default_name="squash"):
        squared_norm = tf.reduce_sum(tf.square(s), axis=axis,
                                     keep_dims=True)
        safe_norm = tf.sqrt(squared_norm + epsilon)
        squash_factor = squared_norm / (1. + squared_norm)
        unit_vector = s / safe_norm
        return squash_factor * unit_vector


def safe_norm(s, axis=-1, epsilon=1e-7, keep_dims=False, name=None):
    with tf.name_scope(name, default_name="safe_norm"):
        squared_norm = tf.reduce_sum(tf.square(s), axis=axis,
                                     keep_dims=keep_dims)
        return tf.sqrt(squared_norm + epsilon)