import tensorflow as tf from tensorflow.examples.tutorials.mnist import input_data
# 载入数据集 mnist = input_data.read_data_sets("MNIST_data", one_hot=True) # 批次大小 batch_size = 64 # 计算一个周期一共有多少个批次 n_batch = mnist.train.num_examples // batch_size with tf.name_scope(‘input‘): # 定义两个placeholder x = tf.placeholder(tf.float32,[None,784], name=‘x-input‘) y = tf.placeholder(tf.float32,[None,10], name=‘y-input‘) with tf.name_scope(‘layer‘): # 创建一个简单的神经网络:784-10 with tf.name_scope(‘weights‘): W = tf.Variable(tf.truncated_normal([784,10], stddev=0.1)) with tf.name_scope(‘biases‘): b = tf.Variable(tf.zeros([10]) + 0.1) with tf.name_scope(‘wx_plus_b‘): wx_plus_b = tf.matmul(x,W)+b with tf.name_scope(‘softmax‘): prediction = tf.nn.softmax(wx_plus_b) with tf.name_scope(‘loss‘): # 二次代价函数 loss = tf.losses.mean_squared_error(y, prediction) with tf.name_scope(‘train‘): # 使用梯度下降法 train = tf.train.GradientDescentOptimizer(0.3).minimize(loss) with tf.name_scope(‘accuracy‘): with tf.name_scope(‘correct_prediction‘): # 结果存放在一个布尔型列表中 correct_prediction = tf.equal(tf.argmax(y,1),tf.argmax(prediction,1)) with tf.name_scope(‘accuracy‘): # 求准确率 accuracy = tf.reduce_mean(tf.cast(correct_prediction,tf.float32)) with tf.Session() as sess: # 变量初始化 sess.run(tf.global_variables_initializer()) writer = tf.summary.FileWriter(‘logs/‘,sess.graph) # # 周期epoch:所有数据训练一次,就是一个周期 # for epoch in range(21): # for batch in range(n_batch): # # 获取一个批次的数据和标签 # batch_xs,batch_ys = mnist.train.next_batch(batch_size) # sess.run(train,feed_dict={x:batch_xs,y:batch_ys}) # # 每训练一个周期做一次测试 # acc = sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels}) # print("Iter " + str(epoch) + ",Testing Accuracy " + str(acc))
原文:https://www.cnblogs.com/liuwenhua/p/11605544.html