TensorFlow中权重的随机初始化的方法


            一开始没看懂stddev是什么参数，找了一下，在tensorflow/python/ops里有random_ops，其中是这么写的：





def random_normal(shape, mean=0.0, stddev=1.0, dtype=types.float32,

         seed=None, name=None):

 """Outputs random values from a normal distribution.



 Args:

  shape: A 1-D integer Tensor or Python array. The shape of the output tensor.

  mean: A 0-D Tensor or Python value of type `dtype`. The mean of the normal

   distribution.

  stddev: A 0-D Tensor or Python value of type `dtype`. The standard deviation

   of the normal distribution.

  dtype: The type of the output.

  seed: A Python integer. Used to create a random seed for the distribution.

   See

   [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)

   for behavior.

  name: A name for the operation (optional).



 Returns:

  A tensor of the specified shape filled with random normal values.

 """







也就是按照正态分布初始化权重，mean是正态分布的平均值，stddev是正态分布的标准差（standard deviation），seed是作为分布的random seed（随机种子，我百度了一下，跟什么伪随机数发生器还有关，就是产生随机数的），在mnist/concolutional中seed赋值为66478，挺有意思，不知道是什么原理。

后面还有truncated_normal的定义：





def truncated_normal(shape, mean=0.0, stddev=1.0, dtype=types.float32,

           seed=None, name=None):

 """Outputs random values from a truncated normal distribution.



 The generated values follow a normal distribution with specified mean and

 standard deviation, except that values whose magnitude is more than 2 standard

 deviations from the mean are dropped and re-picked.



 Args:

  shape: A 1-D integer Tensor or Python array. The shape of the output tensor.

  mean: A 0-D Tensor or Python value of type `dtype`. The mean of the

   truncated normal distribution.

  stddev: A 0-D Tensor or Python value of type `dtype`. The standard deviation

   of the truncated normal distribution.

  dtype: The type of the output.

  seed: A Python integer. Used to create a random seed for the distribution.

   See

   [`set_random_seed`](../../api_docs/python/constant_op.md#set_random_seed)

   for behavior.

  name: A name for the operation (optional).



 Returns:

  A tensor of the specified shape filled with random truncated normal values.

 """







截断正态分布，以前都没听说过。

TensorFlow还提供了平均分布等。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持中文源码网。