莫煩TensorFlow_06

import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt

def add_layer(inputs, in_size, out_size, activation_function = None):
  Weights = tf.Variable(tf.random_normal([in_size, out_size]))  # hang lie
  biases = tf.Variable(tf.zeros([1, out_size]) + 0.1)
  Wx_plus_b = tf.matmul(inputs, Weights) + biases
  if activation_function is None:
    outputs = Wx_plus_b
  else:
    outputs = activation_function(Wx_plus_b)
  return outputs
 
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

#input layer 1 
#hidden layer 10
#output layer 1

xs = tf.placeholder(tf.float32, [None, 1]) # 類似函數的定義
ys = tf.placeholder(tf.float32, [None, 1])

l1 = add_layer(xs, 1, 10, activation_function = tf.nn.relu)
prediction = add_layer(l1, 10, 1, activation_function = None)

loss = tf.reduce_mean(
  tf.reduce_sum(
    tf.square(ys - prediction), 
    reduction_indices=[1]
    )
  )

train_step = tf.train.GradientDescentOptimizer(0.1).minimize(loss)

init = tf.initialize_all_variables()
sess = tf.Session()
sess.run(init)

#可視化
fig = plt.figure()
ax = fig.add_subplot(1,1,1)
ax.scatter(x_data, y_data)
plt.ion() # not frozen
plt.show() # block=False


for i in range(1000):
  sess.run(train_step, feed_dict={xs:x_data, ys:y_data}) # 類似函數變量的輸入
  if i % 50 == 0:
    #print(sess.run(loss, feed_dict={xs:x_data, ys:y_data}))
    try:
      ax.lines.remove(lines[0])
    except Exception:
      pass
    
    prediction_value = sess.run(prediction,feed_dict={xs:x_data})
    lines = ax.plot(x_data, prediction_value, 'r-', lw=5)
    
    plt.pause(0.1)