import tensorflow as tf
import numpy as np
def add_layer(inputs, input_size, out_size, activation_function == None):
Weights = tf.Variable(tf.random_normal([input_size,
out_size]))
biases = tf.Variable(tf.zeros([1, out_size]))
Wx_plus_b = tf.matmul(inputs,Weights) + biases
if activation_function == 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, 0.005, x_data)
y_data = np.square(x_data)-0.5+noise
xs = tf.placeholder(tf.float32, [None, 1])
ys = tf.placeholder(tf.float32,[None, 1])
lay1 = add_layer(xs, 1, 10, activation_function = tf.nn.relu)
prediction = add_layer(layer1, 10, 1, activation_function = None)
loss = tf.reduce_mean(tf.reduce_sum(tf.square(ys - prediction), reduce_indices=[1]))
optimizer = tf.train.GradientDescentOptimizer(0.1)
train_step = optimizer.minimize(loss)
init = tf.initialize_all_variables()
接下来是可视化结果:
先显示原始数据:
import matplotlib.pylot as plt
fig = plt.figure()
ax = fig.add_subplot(111)
ax.scatter(x_data,y_data)
plt.show()
再显示预测数据
with tf.Session() as sess:
sess.run(init)
for i in range(1000):
sess.run(train_step, feed_dict={xs: x_data, ys:
y_data})
if i % 50 == 0:
try:
ax.lines.remove(line[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(0.5)