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

对于张量流2.0,它非常简单

#保存模型 model.save(“path_to_my_model.h5”)

恢复:

new_model = tensorflow.keras.models.load_model('path_to_my_model.h5')

其他回答

对于张量流2.0,它非常简单

#保存模型 model.save(“path_to_my_model.h5”)

恢复:

new_model = tensorflow.keras.models.load_model('path_to_my_model.h5')

在TensorFlow 0.11.0RC1版本中,你可以通过调用tf.train直接保存和恢复你的模型。Export_meta_graph和tf.train。根据https://www.tensorflow.org/programmers_guide/meta_graph的Import_meta_graph。

保存模型

w1 = tf.Variable(tf.truncated_normal(shape=[10]), name='w1')
w2 = tf.Variable(tf.truncated_normal(shape=[20]), name='w2')
tf.add_to_collection('vars', w1)
tf.add_to_collection('vars', w2)
saver = tf.train.Saver()
sess = tf.Session()
sess.run(tf.global_variables_initializer())
saver.save(sess, 'my-model')
# `save` method will call `export_meta_graph` implicitly.
# you will get saved graph files:my-model.meta

恢复模型

sess = tf.Session()
new_saver = tf.train.import_meta_graph('my-model.meta')
new_saver.restore(sess, tf.train.latest_checkpoint('./'))
all_vars = tf.get_collection('vars')
for v in all_vars:
    v_ = sess.run(v)
    print(v_)

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。

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。)

在大多数情况下,使用tf.train.Saver从磁盘保存和恢复是最好的选择:

... # build your model
saver = tf.train.Saver()

with tf.Session() as sess:
    ... # train the model
    saver.save(sess, "/tmp/my_great_model")

with tf.Session() as sess:
    saver.restore(sess, "/tmp/my_great_model")
    ... # use the model

您还可以保存/恢复图结构本身(详细信息请参阅MetaGraph文档)。默认情况下,保存程序将图形结构保存到.meta文件中。您可以调用import_meta_graph()来恢复它。它恢复图形结构并返回一个你可以用来恢复模型状态的保护程序:

saver = tf.train.import_meta_graph("/tmp/my_great_model.meta")

with tf.Session() as sess:
    saver.restore(sess, "/tmp/my_great_model")
    ... # use the model

然而,在某些情况下,您需要更快的方法。例如,如果您实现了早期停止,那么您希望在训练期间每次模型改进时都保存检查点(在验证集上测量),然后如果一段时间内没有进展,则希望回滚到最佳模型。如果每次模型改进时都将其保存到磁盘,则会极大地降低训练速度。诀窍是将变量状态保存到内存中,然后稍后恢复它们:

... # build your model

# get a handle on the graph nodes we need to save/restore the model
graph = tf.get_default_graph()
gvars = graph.get_collection(tf.GraphKeys.GLOBAL_VARIABLES)
assign_ops = [graph.get_operation_by_name(v.op.name + "/Assign") for v in gvars]
init_values = [assign_op.inputs[1] for assign_op in assign_ops]

with tf.Session() as sess:
    ... # train the model

    # when needed, save the model state to memory
    gvars_state = sess.run(gvars)

    # when needed, restore the model state
    feed_dict = {init_value: val
                 for init_value, val in zip(init_values, gvars_state)}
    sess.run(assign_ops, feed_dict=feed_dict)

A quick explanation: when you create a variable X, TensorFlow automatically creates an assignment operation X/Assign to set the variable's initial value. Instead of creating placeholders and extra assignment ops (which would just make the graph messy), we just use these existing assignment ops. The first input of each assignment op is a reference to the variable it is supposed to initialize, and the second input (assign_op.inputs[1]) is the initial value. So in order to set any value we want (instead of the initial value), we need to use a feed_dict and replace the initial value. Yes, TensorFlow lets you feed a value for any op, not just for placeholders, so this works fine.