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
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。
其他回答
特遣部队。keras模型保存TF2.0
我看到了使用TF1.x保存模型的很好的答案。我想提供更多关于保存张量流的提示。Keras模型有点复杂,因为有很多方法来保存一个模型。
这里我提供了一个保存张量流的例子。Keras模型到当前目录下的model_path文件夹。这可以很好地与最新的tensorflow (TF2.0)一起工作。如果在不久的将来有任何变化,我会更新这个描述。
保存和加载整个模型
import tensorflow as tf
from tensorflow import keras
mnist = tf.keras.datasets.mnist
#import data
(x_train, y_train),(x_test, y_test) = mnist.load_data()
x_train, x_test = x_train / 255.0, x_test / 255.0
# create a model
def create_model():
model = tf.keras.models.Sequential([
tf.keras.layers.Flatten(input_shape=(28, 28)),
tf.keras.layers.Dense(512, activation=tf.nn.relu),
tf.keras.layers.Dropout(0.2),
tf.keras.layers.Dense(10, activation=tf.nn.softmax)
])
# compile the model
model.compile(optimizer='adam',
loss='sparse_categorical_crossentropy',
metrics=['accuracy'])
return model
# Create a basic model instance
model=create_model()
model.fit(x_train, y_train, epochs=1)
loss, acc = model.evaluate(x_test, y_test,verbose=1)
print("Original model, accuracy: {:5.2f}%".format(100*acc))
# Save entire model to a HDF5 file
model.save('./model_path/my_model.h5')
# Recreate the exact same model, including weights and optimizer.
new_model = keras.models.load_model('./model_path/my_model.h5')
loss, acc = new_model.evaluate(x_test, y_test)
print("Restored model, accuracy: {:5.2f}%".format(100*acc))
仅保存和加载模型重量
如果您只对保存模型权重感兴趣,然后加载权重以恢复模型,那么
model.fit(x_train, y_train, epochs=5)
loss, acc = model.evaluate(x_test, y_test,verbose=1)
print("Original model, accuracy: {:5.2f}%".format(100*acc))
# Save the weights
model.save_weights('./checkpoints/my_checkpoint')
# Restore the weights
model = create_model()
model.load_weights('./checkpoints/my_checkpoint')
loss,acc = model.evaluate(x_test, y_test)
print("Restored model, accuracy: {:5.2f}%".format(100*acc))
使用keras检查点回调保存和恢复
# include the epoch in the file name. (uses `str.format`)
checkpoint_path = "training_2/cp-{epoch:04d}.ckpt"
checkpoint_dir = os.path.dirname(checkpoint_path)
cp_callback = tf.keras.callbacks.ModelCheckpoint(
checkpoint_path, verbose=1, save_weights_only=True,
# Save weights, every 5-epochs.
period=5)
model = create_model()
model.save_weights(checkpoint_path.format(epoch=0))
model.fit(train_images, train_labels,
epochs = 50, callbacks = [cp_callback],
validation_data = (test_images,test_labels),
verbose=0)
latest = tf.train.latest_checkpoint(checkpoint_dir)
new_model = create_model()
new_model.load_weights(latest)
loss, acc = new_model.evaluate(test_images, test_labels)
print("Restored model, accuracy: {:5.2f}%".format(100*acc))
保存自定义度量的模型
import tensorflow as tf
from tensorflow import keras
mnist = tf.keras.datasets.mnist
(x_train, y_train),(x_test, y_test) = mnist.load_data()
x_train, x_test = x_train / 255.0, x_test / 255.0
# Custom Loss1 (for example)
@tf.function()
def customLoss1(yTrue,yPred):
return tf.reduce_mean(yTrue-yPred)
# Custom Loss2 (for example)
@tf.function()
def customLoss2(yTrue, yPred):
return tf.reduce_mean(tf.square(tf.subtract(yTrue,yPred)))
def create_model():
model = tf.keras.models.Sequential([
tf.keras.layers.Flatten(input_shape=(28, 28)),
tf.keras.layers.Dense(512, activation=tf.nn.relu),
tf.keras.layers.Dropout(0.2),
tf.keras.layers.Dense(10, activation=tf.nn.softmax)
])
model.compile(optimizer='adam',
loss='sparse_categorical_crossentropy',
metrics=['accuracy', customLoss1, customLoss2])
return model
# Create a basic model instance
model=create_model()
# Fit and evaluate model
model.fit(x_train, y_train, epochs=1)
loss, acc,loss1, loss2 = model.evaluate(x_test, y_test,verbose=1)
print("Original model, accuracy: {:5.2f}%".format(100*acc))
model.save("./model.h5")
new_model=tf.keras.models.load_model("./model.h5",custom_objects={'customLoss1':customLoss1,'customLoss2':customLoss2})
使用自定义操作保存keras模型
当我们像下面的例子(tf.tile)一样进行自定义操作时,我们需要创建一个函数并使用Lambda层进行包装。否则,无法保存模型。
import numpy as np
import tensorflow as tf
from tensorflow.keras.layers import Input, Lambda
from tensorflow.keras import Model
def my_fun(a):
out = tf.tile(a, (1, tf.shape(a)[0]))
return out
a = Input(shape=(10,))
#out = tf.tile(a, (1, tf.shape(a)[0]))
out = Lambda(lambda x : my_fun(x))(a)
model = Model(a, out)
x = np.zeros((50,10), dtype=np.float32)
print(model(x).numpy())
model.save('my_model.h5')
#load the model
new_model=tf.keras.models.load_model("my_model.h5")
我想我已经介绍了许多保存tf的方法中的一些。keras模型。然而,还有许多其他的方法。如果你发现你的用例没有在上面提到,请在下面评论。谢谢!
正如Yaroslav所说,您可以通过导入图、手动创建变量,然后使用Saver来从graph_def和检查点进行恢复。
我实现这个是为了我个人使用,所以我想在这里分享一下代码。
链接:https://gist.github.com/nikitakit/6ef3b72be67b86cb7868
(当然,这是一种hack,并且不能保证以这种方式保存的模型在TensorFlow的未来版本中仍然是可读的。)
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')
在新版本的tensorflow 2.0中,保存/加载模型的过程要容易得多。因为Keras API的实现,一个TensorFlow的高级API。
保存一个模型: 请查阅相关文档以作参考: https://www.tensorflow.org/versions/r2.0/api_docs/python/tf/keras/models/save_model
tf.keras.models.save_model(model_name, filepath, save_format)
加载一个模型:
https://www.tensorflow.org/versions/r2.0/api_docs/python/tf/keras/models/load_model
model = tf.keras.models.load_model(filepath)
我在版本:
tensorflow (1.13.1)
tensorflow-gpu (1.13.1)
简单的方法是
拯救策略:
model.save("model.h5")
恢复:
model = tf.keras.models.load_model("model.h5")