Tensorflow 如何从checkpoint文件中加载变量名和变量值

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假设你已经经过上千次的迭代,并且得到了以下模型:

在这里插入图片描述

则从这些checkpoint文件中加载变量名和变量值代码如下:

 model_dir = './ckpt-182802' import tensorflow as tf from tensorflow.python import pywrap_tensorflow reader = pywrap_tensorflow.NewCheckpointReader(model_dir) var_to_shape_map = reader.get_variable_to_shape_map() for key in var_to_shape_map: print("tensor_name: ", key) print(reader.get_tensor(key)) # Remove this is you want to print only variable names 

Mnist

下面将给出一个基于卷积神经网络的手写数字识别样例:

 # -*- coding: utf-8 -*- import tensorflow as tf from tensorflow.examples.tutorials.mnist import input_data from tensorflow.python.framework import graph_util log_dir = './tensorboard' mnist = input_data.read_data_sets(train_dir="./mnist_data",one_hot=True) if tf.gfile.Exists(log_dir): tf.gfile.DeleteRecursively(log_dir) tf.gfile.MakeDirs(log_dir) #定义输入数据mnist图片大小28*28*1=784,None表示batch_size x = tf.placeholder(dtype=tf.float32,shape=[None,28*28],name="input") #定义标签数据,mnist共10类 y_ = tf.placeholder(dtype=tf.float32,shape=[None,10],name="y_") #将数据调整为二维数据,w*H*c---> 28*28*1,-1表示N张 image = tf.reshape(x,shape=[-1,28,28,1]) #第一层,卷积核={5*5*1*32},池化核={2*2*1,1*2*2*1} w1 = tf.Variable(initial_value=tf.random_normal(shape=[5,5,1,32],stddev=0.1,dtype=tf.float32,name="w1")) b1= tf.Variable(initial_value=tf.zeros(shape=[32])) conv1 = tf.nn.conv2d(input=image,filter=w1,strides=[1,1,1,1],padding="SAME",name="conv1") relu1 = tf.nn.relu(tf.nn.bias_add(conv1,b1),name="relu1") pool1 = tf.nn.max_pool(value=relu1,ksize=[1,2,2,1],strides=[1,2,2,1],padding="SAME") #shape={None,14,14,32} #第二层,卷积核={5*5*32*64},池化核={2*2*1,1*2*2*1} w2 = tf.Variable(initial_value=tf.random_normal(shape=[5,5,32,64],stddev=0.1,dtype=tf.float32,name="w2")) b2 = tf.Variable(initial_value=tf.zeros(shape=[64])) conv2 = tf.nn.conv2d(input=pool1,filter=w2,strides=[1,1,1,1],padding="SAME") relu2 = tf.nn.relu(tf.nn.bias_add(conv2,b2),name="relu2") pool2 = tf.nn.max_pool(value=relu2,ksize=[1,2,2,1],strides=[1,2,2,1],padding="SAME",name="pool2") #shape={None,7,7,64} #FC1 w3 = tf.Variable(initial_value=tf.random_normal(shape=[7*7*64,1024],stddev=0.1,dtype=tf.float32,name="w3")) b3 = tf.Variable(initial_value=tf.zeros(shape=[1024])) #关键,进行reshape input3 = tf.reshape(pool2,shape=[-1,7*7*64],name="input3") fc1 = tf.nn.relu(tf.nn.bias_add(value=tf.matmul(input3,w3),bias=b3),name="fc1") #shape={None,1024} #FC2 w4 = tf.Variable(initial_value=tf.random_normal(shape=[1024,10],stddev=0.1,dtype=tf.float32,name="w4")) b4 = tf.Variable(initial_value=tf.zeros(shape=[10])) fc2 = tf.nn.bias_add(value=tf.matmul(fc1,w4),bias=b4,name="logit") #shape={None,10} #定义交叉熵损失 # 使用softmax将NN计算输出值表示为概率 y = tf.nn.softmax(fc2,name="out") # 定义交叉熵损失函数 cross_entropy = tf.nn.softmax_cross_entropy_with_logits(logits=fc2,labels=y_) loss = tf.reduce_mean(cross_entropy) tf.summary.scalar('Cross_Entropy',loss) #定义solver train = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(loss=loss) for var in tf.trainable_variables(): print var #train = tf.train.AdamOptimizer(learning_rate=0.0001).minimize(loss=loss) #定义正确值,判断二者下标index是否相等 correct_predict = tf.equal(tf.argmax(y,1),tf.argmax(y_,1)) #定义如何计算准确率 accuracy = tf.reduce_mean(tf.cast(correct_predict,dtype=tf.float32),name="accuracy") tf.summary.scalar('Training_ACC',accuracy) #定义初始化op merged = tf.summary.merge_all() init = tf.global_variables_initializer() saver = tf.train.Saver() #训练NN with tf.Session() as session: session.run(fetches=init) writer = tf.summary.FileWriter(log_dir,session.graph) #定义记录日志的位置 for i in range(0,500): xs, ys = mnist.train.next_batch(100) session.run(fetches=train,feed_dict={x:xs,y_:ys}) if i%10 == 0: train_accuracy,summary = session.run(fetches=[accuracy,merged],feed_dict={x:xs,y_:ys}) writer.add_summary(summary,i) print(i,"accuracy=",train_accuracy) ''' #训练完成后,将网络中的权值转化为常量,形成常量graph,注意:需要x与label constant_graph = graph_util.convert_variables_to_constants(sess=session, input_graph_def=session.graph_def, output_node_names=['out','y_','input']) #将带权值的graph序列化,写成pb文件存储起来 with tf.gfile.FastGFile("lenet.pb", mode='wb') as f: f.write(constant_graph.SerializeToString()) ''' saver.save(session,'./ckpt') 

补充:查看tensorflow产生的checkpoint文件内容的方法

tensorflow在保存权重模型时多使用tf.train.Saver().save 函数进行权重保存,保存的ckpt文件无法直接打开,但tensorflow提供了相关函数 tf.train.NewCheckpointReader 可以对ckpt文件进行权重查看。

 import os from tensorflow.python import pywrap_tensorflow checkpoint_path = os.path.join('modelckpt', "fc_nn_model") # Read data from checkpoint file reader = pywrap_tensorflow.NewCheckpointReader(checkpoint_path) var_to_shape_map = reader.get_variable_to_shape_map() # Print tensor name and values for key in var_to_shape_map: print("tensor_name: ", key) print(reader.get_tensor(key)) 

其中‘modelckpt'是存放.ckpt文件的文件夹,"fc_nn_model"是文件名,如下图所示。

在这里插入图片描述 

var_to_shape_map是一个字典,其中的键值是变量名,对应的值是该变量的形状,如

 {‘LSTM_input/bias_LSTM/Adam_1': [128]}

想要查看某变量值时,需要调用get_tensor函数,即输入以下代码:

 reader.get_tensor('LSTM_input/bias_LSTM/Adam_1') 

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