卷积神经网络实现-基于MNIST数据集

直接上代码:

#-*- coding:utf-8 -*-
#author : zhangwei

import tensorflow as tf
from tensorflow.examples.tutorials.mnist import input_data

mnist = input_data.read_data_sets("MNIST_data" , one_hot=True)
batch_size = 100
n_batch = mnist.train.num_examples // batch_size

with tf.Graph().as_default():
    def variable_summaries(var):
        with tf.name_scope('summaries'):
            mean = tf.reduce_mean(var)
            tf.summary.scalar('mean' , mean)
            with tf.name_scope('stdeev'):
                stddev = tf.sqrt(tf.reduce_mean(tf.square(var - mean)))
            tf.summary.scalar('stddev' , stddev)
            tf.summary.scalar('max' , tf.reduce_max(var))
            tf.summary.scalar('min' , tf.reduce_min(var))
            tf.summary.histogram('histogram' , var)

    #初始化权重
    def weight_variable(shape , name):
        initial = tf.truncated_normal(shape , stddev=0.1)
        return tf.Variable(initial , name=name)
    #初始化偏置
    def bias_variable(shape , name):
        initial = tf.constant(0.1 , shape=shape)
        return tf.Variable(initial , name=name)
    #卷积层
    def conv2d(x , W):
        return tf.nn.conv2d(x , W , strides=[1 , 1 , 1 , 1] , padding='SAME') #0,3位置都是1,分别代表是x,y方向进行卷积;1 ,2位置代表移动步长,自己设定;
    #池化层
    def max_pool(x):
        return tf.nn.max_pool(x , ksize=[1 , 2 , 2 , 1] ,strides=[1 , 2 , 2 , 1], padding='SAME')

    with tf.name_scope('Input'):
        x = tf.placeholder(tf.float32 , [None , 784] , name='x_input')
        y = tf.placeholder(tf.float32 , [None , 10] , name='y_input')
        with tf.name_scope('x_image'):
            x_image = tf.reshape(x , [-1 , 28 , 28 , 1] , name='x_image')

    with tf.name_scope('Conv1'):
        with tf.name_scope('w_conv1'):
            w_conv1 = weight_variable([3 , 3 , 1 , 64] , name = "w_conv1")
        with tf.name_scope('b_conv1'):
            b_conv1 = bias_variable([64] , name = 'b_conv1')
        with tf.name_scope('conv1'):
            conv1_1 = conv2d(x_image , w_conv1) + b_conv1
        with tf.name_scope('relu'):
            h_conv1 = tf.nn.relu(conv1_1)
        with tf.name_scope('pool1'):
            h_pool1 = max_pool(h_conv1)

    with tf.name_scope('Conv2'):
        with tf.name_scope('w_conv2'):
            w_conv2 = weight_variable([3 , 3 , 64 , 128] , name= 'w_conv2')
        with tf.name_scope('b_conv2'):
            b_conv2 = bias_variable([128] , name='b_conv2')
        with tf.name_scope('conv2'):
            conv2_1 = conv2d(h_pool1 , w_conv2) + b_conv2
        with tf.name_scope('relu'):
            h_conv2 = tf.nn.relu(conv2_1)
        with tf.name_scope('pool2'):
            h_pool2 = max_pool(h_conv2)

    # with tf.name_scope('Conv3'):
    #     with tf.name_scope('w_conv3'):
    #         w_conv3 = weight_variable([3 , 3 , 64 , 64] , name= 'w_conv3')
    #     with tf.name_scope('b_conv3'):
    #         b_conv3 = bias_variable([64] , name='b_conv3')
    #     with tf.name_scope('conv3'):
    #         conv3_1 = conv2d(h_conv2 , w_conv3) + b_conv3
    #     with tf.name_scope('relu'):
    #         h_conv3 = tf.nn.relu(conv3_1)
    #     with tf.name_scope('pool3'):
    #         h_pool1 = max_pool(h_conv3)
    #
    # with tf.name_scope('Conv4'):
    #     with tf.name_scope('w_conv4'):
    #         w_conv4 = weight_variable([3 , 3 , 64 , 128] , name= 'w_conv4')
    #     with tf.name_scope('b_conv4'):
    #         b_conv4 = bias_variable([128] , name='b_conv4')
    #     with tf.name_scope('conv4'):
    #         conv4_1 = conv2d(h_pool1 , w_conv4) + b_conv4
    #     with tf.name_scope('relu'):
    #         h_conv4 = tf.nn.relu(conv4_1)
    #     with tf.name_scope('pool2'):
    #         h_pool2 = max_pool(h_conv4)


    with tf.name_scope('FC1'):
        with tf.name_scope('w_fc1'):
            w_fcl = weight_variable([7*7*128 , 1024] , name='w_fc1')
        with tf.name_scope('b_fc1'):
            b_fc1 = bias_variable([1024] , name = 'b_fc1')
        with tf.name_scope('h_pool2_flat'):
            h_pool2_flat = tf.reshape(h_pool2 , [-1 , 7 * 7 * 128] , name = 'h_pool2_flat')#由于h_pool2的数据是三维数据,需要将其转换到二维;
        with tf.name_scope('wx_plus_b1'):
            wx_plus_b1 = tf.matmul(h_pool2_flat , w_fcl) + b_fc1
        with tf.name_scope('relu'):
            h_fc1 = tf.nn.relu(wx_plus_b1)
        with tf.name_scope('keep_prob'):
            keep_prob = tf.placeholder(tf.float32 , name = 'keep_prob')
        with tf.name_scope('h_fc1_drop'):
            h_fc1_drop = tf.nn.dropout(h_fc1 , keep_prob , name = 'h_fc1_drop')

    with tf.name_scope('FC2'):
        with tf.name_scope('w_fc2'):
            w_fc2 = weight_variable([1024 , 10] , name = 'w_fc2')
        with tf.name_scope('b_fc2'):
            b_fc2 = weight_variable([10] , name = 'b_fc2')
        with tf.name_scope('wx_plus_b2'):
            wx_plus_b2 = tf.matmul(h_fc1_drop , w_fc2) + b_fc2
        with tf.name_scope('sotfmax'):
            prediction = tf.nn.softmax(wx_plus_b2)
        # with tf.name_scope('keep_prob'):
        #     keep_prob = tf.placeholder(tf.float32 , name='keep_prob')
        # with tf.name_scope('h_fc2_drop'):
        #     h_fc2_drop = tf.nn.dropout(h_fc2 , keep_prob , name='h_fc2_prob')

    # with tf.name_scope('FC3'):
    #     with tf.name_scope('w_fc3'):
    #         w_fc3 = weight_variable([1024 , 10] , name = 'w_fc3')
    #     with tf.name_scope('b_fc3'):
    #         b_fc3 = weight_variable([10] , name = 'b_fc3')
    #     with tf.name_scope('wx_plus_b3'):
    #         wx_plus_b3 = tf.matmul(h_fc2_drop , w_fc3) + b_fc3
    #     with tf.name_scope('softmax'):
    #         prediction = tf.nn.softmax(wx_plus_b3)

    with tf.name_scope('cross_entropy'):
        cross_entropy = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(labels=y , logits=prediction) , name='cross_entropy')
        tf.summary.scalar('cross_entropy' , cross_entropy)
    with tf.name_scope('train'):
        train_step = tf.train.AdamOptimizer(1e-4).minimize(cross_entropy)

    with tf.name_scope('accuracy'):
        with tf.name_scope('correct_prediction'):
            correct_prediction = tf.equal(tf.argmax(prediction , 1) , tf.argmax(y , 1))
        with tf.name_scope('accuracy'):
            accuracy = tf.reduce_mean(tf.cast(correct_prediction , tf.float32))
            tf.summary.scalar('accuracy' , accuracy)

    writer = tf.summary.FileWriter(logdir='/home/zhangwei/tensorboard' , graph=tf.get_default_graph())
    writer.close()

    merged = tf.summary.merge_all()

    with tf.Session() as sess:
        init = tf.global_variables_initializer()
        sess.run(init)
        train_writer = tf.summary.FileWriter('/home/zhangwei/PycharmProjects/tensorboard/train' , sess.graph)
        test_writer = tf.summary.FileWriter('/home/zhangwei/PycharmProjects/tensorboard/test' , sess.graph)
        for i in range(500):
            batch_xs , batch_ys = mnist.train.next_batch(batch_size)
            trainloss , _ = sess.run([cross_entropy , train_step] , feed_dict={x : batch_xs , y : batch_ys , keep_prob : 0.6})
            summary = sess.run(merged , feed_dict={x :batch_xs , y : batch_ys , keep_prob : 0.6})
            train_writer.add_summary(summary , i)
            batch_xs , batch_ys = mnist.test.next_batch(batch_size)
            summary = sess.run(merged , feed_dict={x :batch_xs , y :batch_ys , keep_prob : 0.6})
            test_writer.add_summary(summary , i)
            if (i+1) % 5 == 0:
                test_acc = sess.run(accuracy , feed_dict={x : mnist.test.images , y : mnist.test.labels , keep_prob : 1.0})
                train_acc = sess.run(accuracy , feed_dict={x : mnist.train.images[:10000] , y : mnist.train.labels[:10000] ,
                                                           keep_prob : 1.0})
                print "Iter" + str(i+1) + " , Testing Accuracy = " + str(test_acc) + ' , Training Accuracy = ' + str(train_acc) + ' , trainingloss' + str(trainloss)

最后用tensorboard可视化:



由于本人机器计算能力有限,跑100次,损失在不断降低,继续搬砖!

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转载自blog.csdn.net/xwei1226/article/details/80389417