import tensorflow as tf  
import numpy as np  
import matplotlib.pyplot as plt  
  
 #
 # add layer
 #
def add_layer(inputs, in_size, out_size,n_layer, activation_function = None):  
  layer_name = ‘layer%s‘ % n_layer
  with tf.name_scope(layer_name):
    with tf.name_scope(‘Weights‘):
      Weights = tf.Variable(tf.random_normal([in_size, out_size]), name=‘W‘)  # hang lie  
      tf.summary.histogram(layer_name + ‘/weights‘, Weights)
    with tf.name_scope(‘biases‘):
      biases = tf.Variable(tf.zeros([1, out_size]) + 0.1, name = ‘b‘)  
      tf.summary.histogram(layer_name + ‘/biases‘, biases)
    with tf.name_scope(‘Wx_plus_b‘):
      Wx_plus_b = tf.matmul(inputs, Weights) + biases  
    
    if activation_function is None:  
      outputs = Wx_plus_b  
    else:  
      outputs = activation_function(Wx_plus_b)  
      
    tf.summary.histogram(layer_name + ‘/outputs‘, outputs)  
    return outputs  
#
#make up some data
#
x_data = np.linspace(-1,1,300)[:, np.newaxis]
noise  = np.random.normal(0, 0.05, x_data.shape)
y_data = np.square(x_data) - 0.5 + noise
 
#
#define placeholder
#
with tf.name_scope(‘inputs‘):
  xs = tf.placeholder(tf.float32, [None, 1], name = ‘x_input‘) 
  ys = tf.placeholder(tf.float32, [None, 1], name = ‘y_input‘)  

#add hidden layer
l1 = add_layer(xs, 1, 10, n_layer = 1,activation_function = tf.nn.relu)  
#add output layer
prediction = add_layer(l1, 10, 1, n_layer = 2, activation_function = None)  

#the error between prediction and real data  
with tf.name_scope(‘loss‘):
  loss = tf.reduce_mean(tf.reduce_sum(tf.square(ys - prediction),   
				    reduction_indices=[1]  ))  
  tf.summary.scalar(‘loss‘, loss)
  
with tf.name_scope(‘train‘):
  train_step = tf.train.GradientDescentOptimizer(0.1).minimize(loss)  
  
sess = tf.Session()  
merged = tf.summary.merge_all()
writer = tf.summary.FileWriter("logs/", sess.graph)

#import step 
sess.run(tf.global_variables_initializer() )

#
# Session
#

for i in range(1000):
  sess.run(train_step, feed_dict={xs:x_data, ys:y_data}) 
  if i % 50 == 0:
    result = sess.run(merged,
		      feed_dict = {xs:x_data, ys:y_data})
    
    writer.add_summary(result, i)
    print(sess.run(loss, feed_dict={xs:x_data, ys:y_data}))

莫煩TensorFlow_08 tensorboard可視化進階