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  • 跟我学算法-tensorflow 实现卷积神经网络附带保存和读取

    这里的话就不多说明了,因为上上一个博客已经说明了

    import numpy as np
    import  tensorflow as tf
    import matplotlib.pyplot as plt
    from tensorflow.examples.tutorials.mnist import input_data
    mnist = input_data.read_data_sets('data/', one_hot=True)
    
    
    # 构造初始化参数, 方差为0.1
    n_input = 784
    n_output = 10
    weights = {
        'wc1' : tf.Variable(tf.truncated_normal([3, 3, 1, 64], stddev=0.1)),
        'wc2' : tf.Variable(tf.truncated_normal([3, 3, 64, 128], stddev=0.1)),
        'wd1' : tf.Variable(tf.truncated_normal([7*7*128, 1024], stddev=0.1)),
        'wd2' : tf.Variable(tf.truncated_normal([1024, n_output], stddev=0.1))
    
    }
    
    biases = {
        'b1' : tf.Variable(tf.truncated_normal([64], stddev=0.1)),
        'b2' : tf.Variable(tf.truncated_normal([128], stddev=0.1)),
        'bd1' : tf.Variable(tf.truncated_normal([1024], stddev=0.1)),
        'bd2' : tf.Variable(tf.truncated_normal([n_output], stddev=0.1))
    
    }
    
    def conv_basic(_input, _w, _b, _keepratio):
    
        _input_r = tf.reshape(_input, shape=[-1, 28, 28, 1])
        #进行卷积操作
        _conv1 = tf.nn.conv2d(_input_r, _w['wc1'], strides=[1, 1, 1, 1], padding='SAME')
        # 使用激活函数
        _conv1 = tf.nn.relu(tf.nn.bias_add(_conv1, _b['bc1']))
        # 进行池化操作, padding='SAME', 表示维度不足就补齐
        _pool1 = tf.nn.max_pool(_conv1, ksize=[1, 2, 2, 1], stride=[1, 2, 2, 1], padding='SAME')
        #去除一部分数据
        _pool1_dr1 = tf.nn.dropout(_pool1, _keepratio)
        #第二次卷积操作
        _conv2 = tf.nn.conv2d(_pool1_dr1, _w['wc1'], strides=[1, 1, 1, 1], padding='SAME')
        # 使用激活函数
        _conv2 = tf.nn.relu(tf.nn.bias_add(_conv1, _b['bc1']))
        # 进行池化操作
        _pool2 = tf.nn.max_pool(_conv1, ksize=[1, 2, 2, 1], stride=[1, 2, 2, 1], padding='SAME')
        _pool_dr2 = tf.nn.dropout(_pool1, _keepratio)
    
        # 第一次全连接操作
        # 对_pool_dr2 根据wd1重新构造函数
        _densel = tf.reshape(_pool_dr2, [-1, _w['wd1'].get_shape().as_list()[0]])
        _fcl = tf.nn.relu(tf.add(tf.matmul(_densel, _w['wd1'], _b['bd1'])))
        _fc_dr1 = tf.nn.dropout(_fcl, _keepratio)
        # 第二次全连接
        _out = tf.add(tf.matmul(_fc_dr1, _w['wd2']), _b['bd2'])
        out = {'input_r': _input_r, 'conv1': _conv1, 'pool1': _pool1, 'pool1_dr1': _pool_dr1,
               'conv2': _conv2, 'pool2': _pool2, 'pool_dr2': _pool_dr2, 'dense1': _dense1,
               'fcl': _fcl, 'fc_dr1': _fc_dr1, 'out': _out
               }
        return out
    
    
    x = tf.placeholder(tf.float32, [None, n_input])
    y = tf.placeholder(tf.float32, [None, n_output])
    keepratio = tf.placeholder(tf.float32)
    
    # FUNCTIONS
    
    # 构造cost函数
    #获得预测结果
    _pred =conv_basic(x, weights, biases, keepratio)['out']
    # 输入预测结果与真实值构造cost 函数
    cost = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(_pred, y))
    # 优化函数使得cost最小
    optm = tf.train.AdamOptimizer(learning_rate=0.001).minimize(cost)
    # 计算准确率
    _corr = tf.equal(tf.argmax(_pred, 1), tf.argmax(y, 1))
    accr = tf.reduce_mean(tf.cast(_corr, tf.float32))
    init = tf.global_variables_initializer()
    
    # 进行训练
    sess = tf.Session()
    sess.run(init)
    save_step = 1
    # 每次只保存3个值
    saver = tf.train.Saver(max_to_keep=3)
    #迭代次数
    training_epochs = 15
    # 每次训练的样本数
    batch_size      = 16
    #循环打印的次数
    display_step    = 1
    do_train = 1
    if do_train == 1:
        for epoch in range(training_epochs):
            avg_cost = 0.
            #total_batch = int(mnist.train.num_examples/batch_size)
            total_batch = 10
            # Loop over all batches
            for i in range(total_batch):
                # 提取训练数据和标签
                batch_xs, batch_ys = mnist.train.next_batch(batch_size)
                #训练模型优化参数
                sess.run(optm, feed_dict={x: batch_xs, y: batch_ys, keepratio:0.7})
                # 加和损失值
                avg_cost += sess.run(cost, feed_dict={x: batch_xs, y: batch_ys, keepratio:1.})/total_batch
    
            # Display logs per epoch step
            if epoch % display_step == 0:
                print ("Epoch: %03d/%03d cost: %.9f" % (epoch, training_epochs, avg_cost))
                train_acc = sess.run(accr, feed_dict={x: batch_xs, y: batch_ys, keepratio:1.})
                print (" Training accuracy: %.3f" % (train_acc))
                #test_acc = sess.run(accr, feed_dict={x: testimg, y: testlabel, keepratio:1.})
                #print (" Test accuracy: %.3f" % (test_acc))
            if epoch % save_step == 0:
                saver.save(sess, "save/nets/cnn_mnist_basic.ckpt-" + str(epoch))
        print ("OPTIMIZATION FINISHED")
    
    if do_train == 0:
        epoch = training_epochs - 1
        saver.restore(sess, "save/nets/cnn_mnist_basic.ckpt-" + str(epoch))
        # 对测试集进行测试
        feed_test = {x: mnist.test.images, y: mnist.test.labels, keepratio:1.}
        test_acc = sess.run(accr, feed_dict=feed_test)
        print(test_acc)
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  • 原文地址:https://www.cnblogs.com/my-love-is-python/p/9570515.html
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