在Tensorflow中训练一个模型后:
如何拯救训练过的模型? 您以后如何恢复这个保存的模型?
在Tensorflow中训练一个模型后:
如何拯救训练过的模型? 您以后如何恢复这个保存的模型?
当前回答
你也可以用更简单的方法。
步骤1:初始化所有变量
W1 = tf.Variable(tf.truncated_normal([6, 6, 1, K], stddev=0.1), name="W1")
B1 = tf.Variable(tf.constant(0.1, tf.float32, [K]), name="B1")
Similarly, W2, B2, W3, .....
步骤2:在模型Saver中保存会话并保存它
model_saver = tf.train.Saver()
# Train the model and save it in the end
model_saver.save(session, "saved_models/CNN_New.ckpt")
步骤3:恢复模型
with tf.Session(graph=graph_cnn) as session:
model_saver.restore(session, "saved_models/CNN_New.ckpt")
print("Model restored.")
print('Initialized')
步骤4:检查变量
W1 = session.run(W1)
print(W1)
在不同的python实例中运行时,使用
with tf.Session() as sess:
# Restore latest checkpoint
saver.restore(sess, tf.train.latest_checkpoint('saved_model/.'))
# Initalize the variables
sess.run(tf.global_variables_initializer())
# Get default graph (supply your custom graph if you have one)
graph = tf.get_default_graph()
# It will give tensor object
W1 = graph.get_tensor_by_name('W1:0')
# To get the value (numpy array)
W1_value = session.run(W1)
其他回答
您可以保存网络中的变量使用
saver = tf.train.Saver()
saver.save(sess, 'path of save/fileName.ckpt')
要恢复网络以供以后或在另一个脚本中重用,请使用:
saver = tf.train.Saver()
saver.restore(sess, tf.train.latest_checkpoint('path of save/')
sess.run(....)
重要的几点:
第一次运行和以后运行之间的Sess必须相同(一致的结构)。 储蓄者。还原需要保存文件的文件夹路径,而不是单个文件路径。
我正在改进我的回答,以添加更多关于保存和恢复模型的细节。
在Tensorflow 0.11版本中(及之后):
保存模型:
import tensorflow as tf
#Prepare to feed input, i.e. feed_dict and placeholders
w1 = tf.placeholder("float", name="w1")
w2 = tf.placeholder("float", name="w2")
b1= tf.Variable(2.0,name="bias")
feed_dict ={w1:4,w2:8}
#Define a test operation that we will restore
w3 = tf.add(w1,w2)
w4 = tf.multiply(w3,b1,name="op_to_restore")
sess = tf.Session()
sess.run(tf.global_variables_initializer())
#Create a saver object which will save all the variables
saver = tf.train.Saver()
#Run the operation by feeding input
print sess.run(w4,feed_dict)
#Prints 24 which is sum of (w1+w2)*b1
#Now, save the graph
saver.save(sess, 'my_test_model',global_step=1000)
恢复模型:
import tensorflow as tf
sess=tf.Session()
#First let's load meta graph and restore weights
saver = tf.train.import_meta_graph('my_test_model-1000.meta')
saver.restore(sess,tf.train.latest_checkpoint('./'))
# Access saved Variables directly
print(sess.run('bias:0'))
# This will print 2, which is the value of bias that we saved
# Now, let's access and create placeholders variables and
# create feed-dict to feed new data
graph = tf.get_default_graph()
w1 = graph.get_tensor_by_name("w1:0")
w2 = graph.get_tensor_by_name("w2:0")
feed_dict ={w1:13.0,w2:17.0}
#Now, access the op that you want to run.
op_to_restore = graph.get_tensor_by_name("op_to_restore:0")
print sess.run(op_to_restore,feed_dict)
#This will print 60 which is calculated
这里已经很好地解释了这一点和一些更高级的用例。
一个快速完整的教程,保存和恢复Tensorflow模型
你也可以在TensorFlow/skflow中查看例子,它提供了保存和恢复方法,可以帮助你轻松地管理模型。它具有一些参数,您还可以控制备份模型的频率。
下面是一个使用Tensorflow 2.0 SavedModel格式(根据文档,这是推荐的格式)的简单MNIST数据集分类器的简单示例,使用Keras函数式API,没有太多的花哨操作:
# Imports
import tensorflow as tf
from tensorflow.keras.layers import Input, Dense, Flatten
from tensorflow.keras.models import Model
import matplotlib.pyplot as plt
# Load data
mnist = tf.keras.datasets.mnist # 28 x 28
(x_train,y_train), (x_test, y_test) = mnist.load_data()
# Normalize pixels [0,255] -> [0,1]
x_train = tf.keras.utils.normalize(x_train,axis=1)
x_test = tf.keras.utils.normalize(x_test,axis=1)
# Create model
input = Input(shape=(28,28), dtype='float64', name='graph_input')
x = Flatten()(input)
x = Dense(128, activation='relu')(x)
x = Dense(128, activation='relu')(x)
output = Dense(10, activation='softmax', name='graph_output', dtype='float64')(x)
model = Model(inputs=input, outputs=output)
model.compile(optimizer='adam',
loss='sparse_categorical_crossentropy',
metrics=['accuracy'])
# Train
model.fit(x_train, y_train, epochs=3)
# Save model in SavedModel format (Tensorflow 2.0)
export_path = 'model'
tf.saved_model.save(model, export_path)
# ... possibly another python program
# Reload model
loaded_model = tf.keras.models.load_model(export_path)
# Get image sample for testing
index = 0
img = x_test[index] # I normalized the image on a previous step
# Predict using the signature definition (Tensorflow 2.0)
predict = loaded_model.signatures["serving_default"]
prediction = predict(tf.constant(img))
# Show results
print(np.argmax(prediction['graph_output'])) # prints the class number
plt.imshow(x_test[index], cmap=plt.cm.binary) # prints the image
serving_default是什么?
它是所选标记的签名定义的名称(在本例中,选择了默认的服务标记)。此外,本文还解释了如何使用saved_model_cli查找模型的标记和签名。
免责声明
这只是一个基本的例子,如果你只是想让它运行起来,但这绝不是一个完整的答案-也许我可以在未来更新它。我只是想给出一个在TF 2.0中使用SavedModel的简单示例,因为我在任何地方都没有见过这样简单的SavedModel。
@Tom的回答是一个SavedModel的例子,但它在Tensorflow 2.0上不起作用,因为不幸的是有一些突破性的变化。
@Vishnuvardhan Janapati的回答是TF 2.0,但它不适合SavedModel格式。
下面是我对这两种基本情况的简单解决方案,这两种情况的不同之处在于您是想从文件加载图形还是在运行时构建它。
这个答案适用于Tensorflow 0.12+(包括1.0)。
在代码中重建图形
储蓄
graph = ... # build the graph
saver = tf.train.Saver() # create the saver after the graph
with ... as sess: # your session object
saver.save(sess, 'my-model')
加载
graph = ... # build the graph
saver = tf.train.Saver() # create the saver after the graph
with ... as sess: # your session object
saver.restore(sess, tf.train.latest_checkpoint('./'))
# now you can use the graph, continue training or whatever
还从文件中加载图形
当使用这种技术时,确保所有的层/变量都显式地设置了唯一的名称。否则Tensorflow将使名称本身是唯一的,因此它们将不同于存储在文件中的名称。在前一种技术中,这不是问题,因为名称在加载和保存时都以相同的方式“损坏”。
储蓄
graph = ... # build the graph
for op in [ ... ]: # operators you want to use after restoring the model
tf.add_to_collection('ops_to_restore', op)
saver = tf.train.Saver() # create the saver after the graph
with ... as sess: # your session object
saver.save(sess, 'my-model')
加载
with ... as sess: # your session object
saver = tf.train.import_meta_graph('my-model.meta')
saver.restore(sess, tf.train.latest_checkpoint('./'))
ops = tf.get_collection('ops_to_restore') # here are your operators in the same order in which you saved them to the collection