一開(kāi)始沒(méi)看懂stddev是什么參數(shù)，找了一下，在tensorflow/python/ops里有random_ops，其中是這么寫(xiě)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. """

也就是按照正態(tài)分布初始化權(quán)重，mean是正態(tài)分布的平均值，stddev是正態(tài)分布的標(biāo)準(zhǔn)差（standard deviation），seed是作為分布的random seed（隨機(jī)種子，我百度了一下，跟什么偽隨機(jī)數(shù)發(fā)生器還有關(guān)，就是產(chǎn)生隨機(jī)數(shù)的），在mnist/concolutional中seed賦值為66478，挺有意思，不知道是什么原理。

后面還有truncated_normal的定義：

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?cái)嗾龖B(tài)分布，以前都沒(méi)聽(tīng)說(shuō)過(guò)。

TensorFlow還提供了平均分布等。

以上就是本文的全部?jī)?nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持武林站長(zhǎng)站。