本文实例为大家分享了tensorflow实现线性回归的具体代码,供大家参考,具体内容如下
一、随机生成1000个点,分布在y=0.1x+0.3直线周围,并画出来
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import tensorflow as tf import numpy as np import matplotlib.pyplot as plt num_points = 1000 vectors_set = [] for i in range (num_points): x1 = np.random.normal( 0.0 , 0.55 ) / / 设置一定范围的浮动 y1 = x1 * 0.1 + 0.3 + np.random.normal( 0.0 , 0.03 ) vectors_set.append([x1,y1]) x_data = [v[ 0 ] for v in vectors_set] y_data = [v[ 1 ] for v in vectors_set] plt.scatter(x_data,y_data,c = 'r' ) plt.show() |
二、构造线性回归函数
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#生成一维的w矩阵,取值为[-1,1]之间的随机数 w = tf.Variable(tf.random_uniform([ 1 ], - 1.0 , 1.0 ),name = 'W' ) #生成一维的b矩阵,初始值为0 b = tf.Variable(tf.zeros([ 1 ]),name = 'b' ) y = w * x_data + b #均方误差 loss = tf.reduce_mean(tf.square(y - y_data),name = 'loss' ) #梯度下降 optimizer = tf.train.GradientDescentOptimizer( 0.5 ) #最小化loss train = optimizer.minimize(loss,name = 'train' ) sess = tf.Session() init = tf.global_variables_initializer() sess.run(init) #print("W",sess.run(w),"b=",sess.run(b),"loss=",sess.run(loss)) for step in range ( 20 ): sess.run(train) print ( "W=" ,sess.run(w), "b=" ,sess.run(b), "loss=" ,sess.run(loss)) / / 显示拟合后的直线 plt.scatter(x_data,y_data,c = 'r' ) plt.plot(x_data,sess.run(w) * x_data + sess.run(b)) plt.show() |
三、部分训练结果如下:
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W = [ 0.10559751 ] b = [ 0.29925063 ] loss = 0.000887708 W = [ 0.10417549 ] b = [ 0.29926425 ] loss = 0.000884275 W = [ 0.10318361 ] b = [ 0.29927373 ] loss = 0.000882605 W = [ 0.10249177 ] b = [ 0.29928035 ] loss = 0.000881792 W = [ 0.10200921 ] b = [ 0.29928496 ] loss = 0.000881397 W = [ 0.10167261 ] b = [ 0.29928818 ] loss = 0.000881205 W = [ 0.10143784 ] b = [ 0.29929042 ] loss = 0.000881111 W = [ 0.10127408 ] b = [ 0.29929197 ] loss = 0.000881066 |
拟合后的直线如图所示:
结论:最终w趋近于0.1,b趋近于0.3,满足提前设定的数据分布
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:https://blog.csdn.net/Missayaaa/article/details/80053060