#载入数据集
mnist = input_data.read_data_sets("MNIST_data",one_hot=True) #如果没有就下载,然后以独热码的形式载入,有的话就不下载
#每个批次的大小
batch_size =100
#计算一共有多少个批次
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')
#创建一个简单的神经网络
with tf.name_scope('layer'):
with tf.name_scope('weights'):
W = tf.Variable(tf.zeros([784,10]),name='W')
with tf.name_scope('biases'):
b = tf.Variable(tf.zeros([10]),name="b")
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('lose'):
#二次代价函数
loss = tf.reduce_mean(tf.square(y - prediction))
with tf.name_scope('train'):
#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()
with tf.name_scope('accuracy'):
with tf.name_scope('correct_prefdiction'):
#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的值所在的位置
with tf.name_scope('accuracy'):
#求准确率
accuracy = tf.reduce_mean(tf.cast(correct_prediction,tf.float32))
with tf.Session() as sess:
sess.run(init)
wirter = tf.summary.FileWriter('logs/',sess.graph)
for epoch in range(1):
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})
#acc = sess.run(accuracy,feed_dict={x:mnist.test.images,y:mnist.test.labels})
print("Tter"+str(epoch)+",Testing Accuracy"+str(acc))
实线:数据传输
粗细:表示的是两个节点之间传输的标量维度。
使用以下代码可以看多更多的点:
for epoch in range(51):
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})
summary, _ = sess.run([merged, train_step], feed_dict={x: batch_xs, y: batch_ys})
wirter.add_summary(summary, epoch)
acc = sess.run(accuracy, feed_dict={x: mnist.test.images, y: mnist.test.labels})
print("Tter" + str(epoch) + ",Testing Accuracy" + str(acc))