add missing util

utils/symbolic_functions.py

+#!/usr/bin/env python2
+# -*- coding: UTF-8 -*-
+# File: symbolic_functions.py
+# Author: Yuxin Wu <ppwwyyxx@gmail.com>
+
+import tensorflow as tf
+import numpy as np
+__all__ = ['one_hot', 'batch_flatten']
+
+def one_hot(y, num_labels):
+    batch_size = tf.size(y)
+    y = tf.expand_dims(y, 1)
+    indices = tf.expand_dims(tf.range(0, batch_size), 1)
+    concated = tf.concat(1, [indices, y])
+    onehot_labels = tf.sparse_to_dense(
+        concated, tf.pack([batch_size, num_labels]), 1.0, 0.0)
+    onehot_labels.set_shape([None, num_labels])
+    return tf.cast(onehot_labels, tf.float32)
+
+def batch_flatten(x):
+    total_dim = np.prod(x.get_shape()[1:].as_list())
+    return tf.reshape(x, [-1, total_dim])