tf.initialize_all_variables()/tf.global_variables_initializer()
What are the differences between tf.initialize_all_variables() and tf.global_variables_initializer()
注意对于 tf.initialize_all_variables() 接口，TensorFlow 文档有一个重要说明：
tf.initialize_all_variables(): THIS FUNCTION IS DEPRECATED. It will be removed after 2017-03-02. Instructions for updating: Use tf.global_variables_initializer instead.
- tf.initialize_all_variables() 该函数将不再使用，在 2017年3月2号以后；
- 用 tf.global_variables_initializer() 替代 tf.initialize_all_variables()
1. 变量初始化
变量初始化的标准形式：
init = tf.initialize_all_variables()
sess = tf.Session()
sess.run(init)- 1
- 2
- 3
当然也可简写为：
tf.Session().run(tf.initialize_all_variables())- 1
如何有选择地初始化部分变量呢？使用 tf.initialize_variables()，比如要初始化v_6, v_7, v_8三个变量：
init_new_vars_op = tf.initialize_variables([v_6, v_7, v_8])
sess.run(init_new_vars_op)- 1
- 2
2. 识别未被初始化的变量
用 try & except 语句块捕获：
uninit_vars = []
for var in tf.all_variables():try:sess.run(var)except tf.errors.FailedPreconditionError:uninit_vars.append(var)init_new_vars_op = tf.initialize_variables(uninit_vars)- In TensorFlow is there any way to just initialize uninitialised variables?
3. 变量的更新
>> state = tf.Variable(1, name='counter')
>> add_one = tf.add(state, tf.constant(1))
>> update = tf.assign(state, add_one)
>> with tf.Session() as sess:sess.run(tf.gloabl_variables_initializer())sess.run(state)for _ in range(3):sess.run(update)print(sess.run(state))