基本概念二

Layer层

一个层里面要包含的东西

'''
lesson#4 define a layer
Input parameters:
        inputs - X data
        in_size - Matrix row
        Out_size- Matrix col
        Activtion_function default None
'''
from __future__ import print_function
from tensorflow as tf
def add_layer(inputs,in_size,out_size,activation_function=None):  #input 相当于X
    Weights= tf.Variable(tf.random_normal([in_size,out_size])) #矩阵参数
    biases = tf.Variable(tf.zeros([1,out_size]) + 0.1) # bias 不应该为0
    Wx_plus_b = tf.matmul(inputs,Weights) + biases # activation
    if activition_function is None:
        outputs = Wx_plus_b
    else:
        outputs = activation_function(Wx_plus_b)
    return outputs

Build NN