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| 1 | +# View more python learning tutorial on my Youtube and Youku channel!!! |
| 2 | + |
| 3 | +# Youtube video tutorial: https://www.youtube.com/channel/UCdyjiB5H8Pu7aDTNVXTTpcg |
| 4 | +# Youku video tutorial: http://i.youku.com/pythontutorial |
| 5 | + |
| 6 | +import tensorflow as tf |
| 7 | +import numpy as np |
| 8 | +import matplotlib.pyplot as plt |
| 9 | + |
| 10 | +def add_layer(inputs, in_size, out_size, activation_function=None): |
| 11 | + Weights = tf.Variable(tf.random_normal([in_size, out_size])) |
| 12 | + biases = tf.Variable(tf.zeros([1, out_size]) + 0.1) |
| 13 | + Wx_plus_b = tf.matmul(inputs, Weights) + biases |
| 14 | + if activation_function is None: |
| 15 | + outputs = Wx_plus_b |
| 16 | + else: |
| 17 | + outputs = activation_function(Wx_plus_b) |
| 18 | + return outputs |
| 19 | + |
| 20 | +# Make up some real data |
| 21 | +x_data = np.linspace(-1, 1, 300)[:, np.newaxis] |
| 22 | +noise = np.random.normal(0, 0.05, x_data.shape) |
| 23 | +y_data = np.square(x_data) - 0.5 + noise |
| 24 | + |
| 25 | +##plt.scatter(x_data, y_data) |
| 26 | +##plt.show() |
| 27 | + |
| 28 | +# define placeholder for inputs to network |
| 29 | +xs = tf.placeholder(tf.float32, [None, 1]) |
| 30 | +ys = tf.placeholder(tf.float32, [None, 1]) |
| 31 | +# add hidden layer |
| 32 | +l1 = add_layer(xs, 1, 10, activation_function=tf.nn.relu) |
| 33 | +# add output layer |
| 34 | +prediction = add_layer(l1, 10, 1, activation_function=None) |
| 35 | + |
| 36 | +# the error between prediciton and real data |
| 37 | +loss = tf.reduce_mean(tf.reduce_sum(tf.square(ys-prediction), reduction_indices=[1])) |
| 38 | +train_step = tf.train.GradientDescentOptimizer(0.1).minimize(loss) |
| 39 | +# important step |
| 40 | +init = tf.initialize_all_variables() |
| 41 | +sess= tf.Session() |
| 42 | +sess.run(init) |
| 43 | + |
| 44 | +# plot the real data |
| 45 | +fig = plt.figure() |
| 46 | +ax = fig.add_subplot(1,1,1) |
| 47 | +ax.scatter(x_data, y_data) |
| 48 | +plt.ion() |
| 49 | +plt.show() |
| 50 | + |
| 51 | + |
| 52 | +for i in range(1000): |
| 53 | + # training |
| 54 | + sess.run(train_step, feed_dict={xs: x_data, ys: y_data}) |
| 55 | + if i % 50 == 0: |
| 56 | + # to visualize the result and improvement |
| 57 | + try: |
| 58 | + ax.lines.remove(lines[0]) |
| 59 | + except Exception: |
| 60 | + pass |
| 61 | + prediction_value = sess.run(prediction, feed_dict={xs: x_data}) |
| 62 | + # plot the prediction |
| 63 | + lines = ax.plot(x_data, prediction_value, 'r-', lw=5) |
| 64 | + plt.pause(1) |
| 65 | + |
| 66 | + |
| 67 | + |
| 68 | + |
| 69 | + |
| 70 | + |
| 71 | + |
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