基于tensorflow改写的mnist手写数字识别

阳光穿透心脏的1/2处 2022-04-10 04:14 323阅读 0赞

隐藏层两层，神经元个数可以自定义，学习率采用退化学习率。尽了最大努力，最大识别率目前还不到98%，有没有高手指点一下？

# -*- coding: UTF-8 -*-
    #主程序
    import numpy as np
    import tensorflow as tf
    from mnistread import *
    
    hidden_layer1_cells=400
    hidden_layer2_cells=100
    tf.reset_default_graph()
    X=tf.placeholder(tf.float32,[None,784])
    Y=tf.placeholder(tf.float32,[None,10])
    Z=tf.placeholder(tf.float32,[None,10])
    OH=tf.placeholder(tf.int32,[None])
    onehot=tf.one_hot(OH,depth=10,axis=1)
    
    batchsize=100
    epochs=1000
    current_iter=tf.Variable(0)
    W={ 
        "wih":tf.Variable(tf.random_normal([784,hidden_layer1_cells]),name="wih"),
        "whh":tf.Variable(tf.random_normal([hidden_layer1_cells,hidden_layer2_cells]),name="whh"),
        "who":tf.Variable(tf.random_normal([hidden_layer2_cells,10]),name="who")
    }
    B={ 
        "bih":tf.Variable(tf.random_uniform([hidden_layer1_cells],dtype=tf.float32),name="bih"),
        "bhh":tf.Variable(tf.random_uniform([hidden_layer2_cells],dtype=tf.float32),name="bhh"),
        "bho":tf.Variable(tf.random_uniform([10],dtype=tf.float32),name="bho")
    }
    layer1=tf.nn.tanh(tf.matmul(X,W["wih"])+B["bih"])
    layer2=tf.nn.tanh(tf.matmul(layer1,W["whh"])+B["bhh"])
    Y=tf.matmul(layer2,W["who"])+B["bho"]
    out=tf.nn.softmax(Y)
    cost=tf.nn.softmax_cross_entropy_with_logits_v2(labels=Z, logits=Y)
    lr=tf.train.exponential_decay(0.01,current_iter,6000,0.9,staircase=True)
    optimizer=tf.train.AdamOptimizer(lr).minimize(cost,current_iter)
    train_X=(load_train_images()/255*0.99)+0.01
    train_X=np.reshape(train_X,[-1,784])
    train_Y=load_train_labels()
    loss=0.0
    saver=tf.train.Saver()
    
    test_images=np.reshape((load_train_images('./t10k-images.idx3-ubyte')/255*0.99)+0.01,[-1,784])
    test_labels=load_train_labels('./t10k-labels.idx1-ubyte')
    
    with tf.Session() as sess:
        sess.run(tf.global_variables_initializer())
        for i in range(epochs):
            current_iter=i
            batchs=len(train_X)//batchsize
            z=np.zeros([batchsize,10])
            for j in range(batchs):
                x=train_X[j*batchsize:(j+1)*batchsize,:]
                z=train_Y[j*batchsize:(j+1)*batchsize].astype("int32")
                z=sess.run(onehot,feed_dict={ OH:z})
                _,loss,o=sess.run([optimizer,cost,out],feed_dict={ X:x,Z:z})
            test_out=sess.run(out,feed_dict={ X:test_images})
            result=np.argmax(test_out,1)
            z=test_labels.astype("int32")
            accuracy=len(np.argwhere(z==result))
            print("Epoch:",i,"Loss:",np.mean(loss),"Accuracy:",accuracy)
            print("----------------------------------------------------------------")
        saver.save(sess,"./mnistconfig.ckpt")
        print("Finised and saved")

## mnist训练数据和测试数据读取函数：mnistread.py内容： ##

# -*- coding: UTF-8 -*-
    import numpy as np
    import tensorflow as tf
    import matplotlib.pylab as pl
    import struct
    # 训练集文件
    train_images_idx3_ubyte_file = './train-images.idx3-ubyte'
    # 训练集标签文件
    train_labels_idx1_ubyte_file = './train-labels.idx1-ubyte'
    
    # 测试集文件
    test_images_idx3_ubyte_file = './t10k-images.idx3-ubyte'
    # 测试集标签文件
    test_labels_idx1_ubyte_file = './t10k-labels.idx1-ubyte'
    
    
    def decode_idx3_ubyte(idx3_ubyte_file):
        """ 解析idx3文件的通用函数 :param idx3_ubyte_file: idx3文件路径 :return: 数据集 """
        # 读取二进制数据
        bin_data = open(idx3_ubyte_file, 'rb').read()
    
        # 解析文件头信息，依次为魔数、图片数量、每张图片高、每张图片宽
        offset = 0
        fmt_header = '>iiii'
        magic_number, num_images, num_rows, num_cols = struct.unpack_from(fmt_header, bin_data, offset)
        #print '魔数:%d, 图片数量: %d张, 图片大小: %d*%d' % (magic_number, num_images, num_rows, num_cols)
    
        # 解析数据集
        image_size = num_rows * num_cols
        offset += struct.calcsize(fmt_header)
        fmt_image = '>' + str(image_size) + 'B'
        images = np.empty((num_images, num_rows, num_cols))
        for i in range(num_images):
            images[i] = np.array(struct.unpack_from(fmt_image, bin_data, offset)).reshape((num_rows, num_cols))
            offset += struct.calcsize(fmt_image)
        return images
    
    
    def decode_idx1_ubyte(idx1_ubyte_file):
        """ 解析idx1文件的通用函数 :param idx1_ubyte_file: idx1文件路径 :return: 数据集 """
        # 读取二进制数据
        bin_data = open(idx1_ubyte_file, 'rb').read()
    
        # 解析文件头信息，依次为魔数和标签数
        offset = 0
        fmt_header = '>ii'
        magic_number, num_images = struct.unpack_from(fmt_header, bin_data, offset)
        #print '魔数:%d, 图片数量: %d张' % (magic_number, num_images)
    
        # 解析数据集
        offset += struct.calcsize(fmt_header)
        fmt_image = '>B'
        labels = np.empty(num_images)
        for i in range(num_images):
            labels[i] = struct.unpack_from(fmt_image, bin_data, offset)[0]
            offset += struct.calcsize(fmt_image)
        return labels
    def load_train_images(idx_ubyte_file=train_images_idx3_ubyte_file):
        return decode_idx3_ubyte(idx_ubyte_file)
    def load_train_labels(idx_ubyte_file=train_labels_idx1_ubyte_file):
        return decode_idx1_ubyte(idx_ubyte_file)