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初識GAN之MNIST手寫數字的識別

初識GAN,因為剛好在嘗試用純python實現手寫數字的識別,所以在這裡也嘗試了一下。筆者也是根據網上教程一步步來的,不多說了,程式碼如下:

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

mnist = input_data.read_data_sets('MNIST_data', one_hot=True)#下載檔案在MNIST_data資料夾中
sess=tf.InteractiveSession()

def conv2d(x,w):
    return tf.nn.
conv2d(x,w,strides=[1,1,1,1],padding='SAME') def max_pool_2x2(x): return tf.nn.max_pool(x,ksize=[1,2,2,1],strides=[1,2,2,1],padding='SAME') x=tf.placeholder(tf.float32,[None,784]) y_=tf.placeholder(tf.float32,[None,10]) x_img=tf.reshape(x,[-1,28,28,1]) #第一個卷積層和池化層 w_conv1=tf.Variable(tf.truncated_normal(
[3,3,1,32],stddev=0.1))# 生成矩陣,矩陣中元素是均值為0,標準差為0.1的隨機數,權值使用方差為0.1的截斷正態分佈(指最大值不超過方差兩倍的分佈)來初始化,偏置的初值設定為常值0.1。 b_conv1=tf.Variable(tf.constant(0.1,shape=[32])) #建立一個常數張量,傳入list或者數值來填充 h_conv1=tf.nn.relu(conv2d(x_img,w_conv1)+b_conv1) h_pool1=max_pool_2x2(h_conv1) #第二個卷積層和池化層 w_conv2=tf.Variable(tf.truncated_normal(
[3,3,32,50],stddev=0.1)) b_conv2=tf.Variable(tf.constant(0.1,shape=[50])) h_conv2=tf.nn.relu(conv2d(h_pool1,w_conv2)+b_conv2) h_pool2=max_pool_2x2(h_conv2) #第一個全連線層 w_fc1=tf.Variable(tf.truncated_normal([7*7*50,1024],stddev=0.1)) b_fc1=tf.Variable(tf.constant(0.1,shape=[1024])) h_pool2_flat=tf.reshape(h_pool2,[-1,7*7*50]) h_fc1=tf.nn.relu(tf.matmul(h_pool2_flat,w_fc1)+b_fc1) #dropout(隨機權重失活) keep_prob=tf.placeholder(tf.float32) h_fc1_drop=tf.nn.dropout(h_fc1,keep_prob) #第二個全連線層 w_fc2=tf.Variable(tf.truncated_normal([1024,10],stddev=0.1)) b_fc2=tf.Variable(tf.constant(0.1,shape=[10])) y_out=tf.nn.softmax(tf.matmul(h_fc1_drop,w_fc2)+b_fc2) #loss function,交叉熵,配置Adam優化器,學習速率:1e-4 loss=tf.reduce_mean(-tf.reduce_sum(y_*tf.log(y_out),reduction_indices=[1])) train_step=tf.train.AdamOptimizer(1e-4).minimize(loss) #建立正確率計算表示式 correct_prediction=tf.equal(tf.argmax(y_out,1),tf.argmax(y_,1)) accuracy=tf.reduce_mean(tf.cast(correct_prediction,tf.float32)) #測試 tf.global_variables_initializer().run() for i in range(20000): batch=mnist.train.next_batch(50) if i%100 == 0: train_accuracy = accuracy.eval(feed_dict={x:batch[0],y_:batch[1],keep_prob:1}) print("step",i, ",train_accuracy",train_accuracy) print("test_accuracy=",accuracy.eval(feed_dict={x:mnist.test.images,y_:mnist.test.labels,keep_prob:1}))