Tensorflow学习3:非线性回归

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import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt
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# 用numpy生成200个随机点
x_data = np.linspace(-0.5, 0.5, 200)[:,np.newaxis] #增加一个维度,变成单列矩阵
noise = np.random.normal(0,0.02,x_data.shape)
y_data = np.square(x_data) + noise

#
x = tf.placeholder(tf.float32,[None,1])
y = tf.placeholder(tf.float32,[None,1])

Weights_L1 = tf.Variable(tf.random_normal((1,10)))
biases_L1 = tf.Variable(tf.zeros((1,10)))
Wx_plus_b_L1 = tf.matmul(x, Weights_L1) + biases_L1
L1 = tf.nn.softplus(Wx_plus_b_L1)

Weights_L2 = tf.Variable(tf.random_normal((10,1)))
biases_L2 = tf.Variable(tf.zeros((1,1)))
Wx_plus_Biases_L2 = tf.matmul(L1, Weights_L2) + biases_L2
#predict_y = tf.nn.tanh(Wx_plus_Biases_L2)
predict_y = Wx_plus_Biases_L2

loss = tf.reduce_mean(tf.square(predict_y - y))
train = tf.train.GradientDescentOptimizer(0.1).minimize(loss)

with tf.Session() as sess:
sess.run(tf.global_variables_initializer())
for _ in range(1000):
sess.run(train, feed_dict={x:x_data, y:y_data})

_predict_y = sess.run(predict_y, feed_dict={x:x_data})
plt.figure()
plt.scatter(x_data, y_data)
plt.plot(x_data, _predict_y, "red", lw=5)
plt.show()

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