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) #每个批次100张照片 batch_size = 100 #计算一共有多少个批次 n_batch = mnist.train.num_examples // batch_size #定义两个placeholder x = tf.placeholder(tf.float32,[None,784]) y = tf.placeholder(tf.float32,[None,10]) #创建一个简单的神经网络,输入层784个神经元,输出层10个神经元 W = tf.Variable(tf.zeros([784,10])) b = tf.Variable(tf.zeros([10])) prediction = tf.nn.softmax(tf.matmul(x,W)+b) #二次代价函数 # loss = tf.reduce_mean(tf.square(y-prediction)) loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=y,logits=prediction)) #使用梯度下降法 train_step = tf.train.GradientDescentOptimizer(0.2).minimize(loss) #初始化变量 init = tf.global_variables_initializer() #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))#argmax返回一维张量中最大的值所在的位置 #求准确率 accuracy = tf.reduce_mean(tf.cast(correct_prediction,tf.float32)) saver = tf.train.Saver() with tf.Session() as sess: sess.run(init) for epoch in range(11): for batch in range(n_batch): batch_xs,batch_ys = mnist.train.next_batch(batch_size) sess.run(train_step,feed_dict={x:batch_xs,y:batch_ys}) acc = sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels}) print("Iter " + str(epoch) + ",Testing Accuracy " + str(acc)) #保存模型 saver.save(sess,'net/my_net.ckpt')
以上是保存模型;
#载入数据集 mnist = input_data.read_data_sets("MNIST_data",one_hot=True) #每个批次100张照片 batch_size = 100 #计算一共有多少个批次 n_batch = mnist.train.num_examples // batch_size #定义两个placeholder x = tf.placeholder(tf.float32,[None,784]) y = tf.placeholder(tf.float32,[None,10]) #创建一个简单的神经网络,输入层784个神经元,输出层10个神经元 W = tf.Variable(tf.zeros([784,10])) b = tf.Variable(tf.zeros([10])) prediction = tf.nn.softmax(tf.matmul(x,W)+b) #二次代价函数 # loss = tf.reduce_mean(tf.square(y-prediction)) loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=y,logits=prediction)) #使用梯度下降法 train_step = tf.train.GradientDescentOptimizer(0.2).minimize(loss) #初始化变量 init = tf.global_variables_initializer() #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))#argmax返回一维张量中最大的值所在的位置 #求准确率 accuracy = tf.reduce_mean(tf.cast(correct_prediction,tf.float32)) saver = tf.train.Saver() with tf.Session() as sess: sess.run(init) print(sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels})) saver.restore(sess,'net/my_net.ckpt') print(sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels}))
#
0.098 INFO:tensorflow:Restoring parameters from net/my_net.ckpt 0.9179
以下是载入模型,第一个print是看看随机生成的参数用于预测分类的结果;第二个print是看看载入的模型来预测分类的结果。