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
tensorflow - 2.0
这很简单。
import tensorflow as tf
SAVE
model.save("model_name")
恢复
model = tf.keras.models.load_model('model_name')
其他回答
tensorflow - 2.0
这很简单。
import tensorflow as tf
SAVE
model.save("model_name")
恢复
model = tf.keras.models.load_model('model_name')
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。
对于TensorFlow版本< 0.11.0RC1:
保存的检查点包含模型中的变量值,而不是模型/图本身,这意味着当您恢复检查点时,图应该是相同的。
这里有一个线性回归的例子,其中有一个训练循环,保存变量检查点,还有一个评估部分,将恢复之前运行中保存的变量并计算预测。当然,如果你愿意,你也可以恢复变量并继续训练。
x = tf.placeholder(tf.float32)
y = tf.placeholder(tf.float32)
w = tf.Variable(tf.zeros([1, 1], dtype=tf.float32))
b = tf.Variable(tf.ones([1, 1], dtype=tf.float32))
y_hat = tf.add(b, tf.matmul(x, w))
...more setup for optimization and what not...
saver = tf.train.Saver() # defaults to saving all variables - in this case w and b
with tf.Session() as sess:
sess.run(tf.initialize_all_variables())
if FLAGS.train:
for i in xrange(FLAGS.training_steps):
...training loop...
if (i + 1) % FLAGS.checkpoint_steps == 0:
saver.save(sess, FLAGS.checkpoint_dir + 'model.ckpt',
global_step=i+1)
else:
# Here's where you're restoring the variables w and b.
# Note that the graph is exactly as it was when the variables were
# saved in a prior training run.
ckpt = tf.train.get_checkpoint_state(FLAGS.checkpoint_dir)
if ckpt and ckpt.model_checkpoint_path:
saver.restore(sess, ckpt.model_checkpoint_path)
else:
...no checkpoint found...
# Now you can run the model to get predictions
batch_x = ...load some data...
predictions = sess.run(y_hat, feed_dict={x: batch_x})
下面是变量文档,涵盖了保存和恢复。这是保存程序的文档。
使用tf.train.Saver保存模型。记住,如果想要减小模型大小,就需要指定var_list。val_list可以是:
特遣部队。trainable_variables或 tf.global_variables。
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