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# Create some variables.
v1 = tf.get_variable("v1", shape=[3], initializer = tf.zeros_initializer)
v2 = tf.get_variable("v2", shape=[5], initializer = tf.zeros_initializer)
inc_v1 = v1.assign(v1+1)
dec_v2 = v2.assign(v2-1)
# Add an op to initialize the variables.
init_op = tf.global_variables_initializer()
# Add ops to save and restore all the variables.
saver = tf.train.Saver()
# Later, launch the model, initialize the variables, do some work, and save the
# variables to disk.
with tf.Session() as sess:
sess.run(init_op)
# Do some work with the model.
inc_v1.op.run()
dec_v2.op.run()
# Save the variables to disk.
save_path = saver.save(sess, "/tmp/model.ckpt")
print("Model saved in path: %s" % save_path)
戻す
tf.reset_default_graph()
# Create some variables.
v1 = tf.get_variable("v1", shape=[3])
v2 = tf.get_variable("v2", shape=[5])
# Add ops to save and restore all the variables.
saver = tf.train.Saver()
# Later, launch the model, use the saver to restore variables from disk, and
# do some work with the model.
with tf.Session() as sess:
# Restore variables from disk.
saver.restore(sess, "/tmp/model.ckpt")
print("Model restored.")
# Check the values of the variables
print("v1 : %s" % v1.eval())
print("v2 : %s" % v2.eval())
Tensorflow 2
これはまだベータ版なので、今はお勧めしません。それでもその道を進みたい場合は、ここに使用ガイドがありtf.saved_modelます
Tensorflow <2
simple_save
良い答えがたくさんあります。完全を期すために、2セントを追加します：simple_save。また、tf.data.DatasetAPI を使用したスタンドアロンコードの例。
Python 3; Tensorflow 1.14
import tensorflow as tf
from tensorflow.saved_model import tag_constants
with tf.Graph().as_default():
with tf.Session() as sess:
...
# Saving
inputs = {
"batch_size_placeholder": batch_size_placeholder,
"features_placeholder": features_placeholder,
"labels_placeholder": labels_placeholder,
}
outputs = {"prediction": model_output}
tf.saved_model.simple_save(
sess, 'path/to/your/location/', inputs, outputs
)
復元：
graph = tf.Graph()
with restored_graph.as_default():
with tf.Session() as sess:
tf.saved_model.loader.load(
sess,
[tag_constants.SERVING],
'path/to/your/location/',
)
batch_size_placeholder = graph.get_tensor_by_name('batch_size_placeholder:0')
features_placeholder = graph.get_tensor_by_name('features_placeholder:0')
labels_placeholder = graph.get_tensor_by_name('labels_placeholder:0')
prediction = restored_graph.get_tensor_by_name('dense/BiasAdd:0')
sess.run(prediction, feed_dict={
batch_size_placeholder: some_value,
features_placeholder: some_other_value,
labels_placeholder: another_value
})
スタンドアロンの例
元のブログ投稿
次のコードは、デモンストレーションのためにランダムデータを生成します。
- まず、プレースホルダーを作成します。実行時にデータを保持します。それらから、を作成し
Dataset、次にを作成しますIterator。イテレータの生成されたテンソルを取得しますinput_tensor。これは、モデルへの入力として機能します。
- モデル自体は
input_tensor、GRUベースの双方向RNNとそれに続く密な分類子から構築されます。それはなぜか。
- 損失は、
softmax_cross_entropy_with_logitsで最適化されていAdamます。（それぞれ2バッチの）2エポックの後、「トレーニング済み」モデルをで保存しtf.saved_model.simple_saveます。コードをそのまま実行すると、モデルはsimple/現在の作業ディレクトリにあるフォルダーに保存されます。
- 新しいグラフでは、保存したモデルをで復元し
tf.saved_model.loader.loadます。でプレースホルダーとロジットをgraph.get_tensor_by_name、でIterator初期化操作を取得しgraph.get_operation_by_nameます。
- 最後に、データセットの両方のバッチに対して推論を実行し、保存されたモデルと復元されたモデルの両方が同じ値を生成することを確認します。彼らはします！
コード：
import os
import shutil
import numpy as np
import tensorflow as tf
from tensorflow.python.saved_model import tag_constants
def model(graph, input_tensor):
"""Create the model which consists of
a bidirectional rnn (GRU(10)) followed by a dense classifier
Args:
graph (tf.Graph): Tensors' graph
input_tensor (tf.Tensor): Tensor fed as input to the model
Returns:
tf.Tensor: the model's output layer Tensor
"""
cell = tf.nn.rnn_cell.GRUCell(10)
with graph.as_default():
((fw_outputs, bw_outputs), (fw_state, bw_state)) = tf.nn.bidirectional_dynamic_rnn(
cell_fw=cell,
cell_bw=cell,
inputs=input_tensor,
sequence_length=[10] * 32,
dtype=tf.float32,
swap_memory=True,
scope=None)
outputs = tf.concat((fw_outputs, bw_outputs), 2)
mean = tf.reduce_mean(outputs, axis=1)
dense = tf.layers.dense(mean, 5, activation=None)
return dense
def get_opt_op(graph, logits, labels_tensor):
"""Create optimization operation from model's logits and labels
Args:
graph (tf.Graph): Tensors' graph
logits (tf.Tensor): The model's output without activation
labels_tensor (tf.Tensor): Target labels
Returns:
tf.Operation: the operation performing a stem of Adam optimizer
"""
with graph.as_default():
with tf.variable_scope('loss'):
loss = tf.reduce_mean(tf.nn.softmax_cross_entropy_with_logits(
logits=logits, labels=labels_tensor, name='xent'),
name="mean-xent"
)
with tf.variable_scope('optimizer'):
opt_op = tf.train.AdamOptimizer(1e-2).minimize(loss)
return opt_op
if __name__ == '__main__':
# Set random seed for reproducibility
# and create synthetic data
np.random.seed(0)
features = np.random.randn(64, 10, 30)
labels = np.eye(5)[np.random.randint(0, 5, (64,))]
graph1 = tf.Graph()
with graph1.as_default():
# Random seed for reproducibility
tf.set_random_seed(0)
# Placeholders
batch_size_ph = tf.placeholder(tf.int64, name='batch_size_ph')
features_data_ph = tf.placeholder(tf.float32, [None, None, 30], 'features_data_ph')
labels_data_ph = tf.placeholder(tf.int32, [None, 5], 'labels_data_ph')
# Dataset
dataset = tf.data.Dataset.from_tensor_slices((features_data_ph, labels_data_ph))
dataset = dataset.batch(batch_size_ph)
iterator = tf.data.Iterator.from_structure(dataset.output_types, dataset.output_shapes)
dataset_init_op = iterator.make_initializer(dataset, name='dataset_init')
input_tensor, labels_tensor = iterator.get_next()
# Model
logits = model(graph1, input_tensor)
# Optimization
opt_op = get_opt_op(graph1, logits, labels_tensor)
with tf.Session(graph=graph1) as sess:
# Initialize variables
tf.global_variables_initializer().run(session=sess)
for epoch in range(3):
batch = 0
# Initialize dataset (could feed epochs in Dataset.repeat(epochs))
sess.run(
dataset_init_op,
feed_dict={
features_data_ph: features,
labels_data_ph: labels,
batch_size_ph: 32
})
values = []
while True:
try:
if epoch < 2:
# Training
_, value = sess.run([opt_op, logits])
print('Epoch {}, batch {} | Sample value: {}'.format(epoch, batch, value[0]))
batch += 1
else:
# Final inference
values.append(sess.run(logits))
print('Epoch {}, batch {} | Final inference | Sample value: {}'.format(epoch, batch, values[-1][0]))
batch += 1
except tf.errors.OutOfRangeError:
break
# Save model state
print('\nSaving...')
cwd = os.getcwd()
path = os.path.join(cwd, 'simple')
shutil.rmtree(path, ignore_errors=True)
inputs_dict = {
"batch_size_ph": batch_size_ph,
"features_data_ph": features_data_ph,
"labels_data_ph": labels_data_ph
}
outputs_dict = {
"logits": logits
}
tf.saved_model.simple_save(
sess, path, inputs_dict, outputs_dict
)
print('Ok')
# Restoring
graph2 = tf.Graph()
with graph2.as_default():
with tf.Session(graph=graph2) as sess:
# Restore saved values
print('\nRestoring...')
tf.saved_model.loader.load(
sess,
[tag_constants.SERVING],
path
)
print('Ok')
# Get restored placeholders
labels_data_ph = graph2.get_tensor_by_name('labels_data_ph:0')
features_data_ph = graph2.get_tensor_by_name('features_data_ph:0')
batch_size_ph = graph2.get_tensor_by_name('batch_size_ph:0')
# Get restored model output
restored_logits = graph2.get_tensor_by_name('dense/BiasAdd:0')
# Get dataset initializing operation
dataset_init_op = graph2.get_operation_by_name('dataset_init')
# Initialize restored dataset
sess.run(
dataset_init_op,
feed_dict={
features_data_ph: features,
labels_data_ph: labels,
batch_size_ph: 32
}
)
# Compute inference for both batches in dataset
restored_values = []
for i in range(2):
restored_values.append(sess.run(restored_logits))
print('Restored values: ', restored_values[i][0])
# Check if original inference and restored inference are equal
valid = all((v == rv).all() for v, rv in zip(values, restored_values))
print('\nInferences match: ', valid)
これは印刷されます：
$ python3 save_and_restore.py
Epoch 0, batch 0 | Sample value: [-0.13851789 -0.3087595 0.12804556 0.20013677 -0.08229901]
Epoch 0, batch 1 | Sample value: [-0.00555491 -0.04339041 -0.05111827 -0.2480045 -0.00107776]
Epoch 1, batch 0 | Sample value: [-0.19321944 -0.2104792 -0.00602257 0.07465433 0.11674127]
Epoch 1, batch 1 | Sample value: [-0.05275984 0.05981954 -0.15913513 -0.3244143 0.10673307]
Epoch 2, batch 0 | Final inference | Sample value: [-0.26331693 -0.13013336 -0.12553 -0.04276478 0.2933622 ]
Epoch 2, batch 1 | Final inference | Sample value: [-0.07730117 0.11119192 -0.20817074 -0.35660955 0.16990358]
Saving...
INFO:tensorflow:Assets added to graph.
INFO:tensorflow:No assets to write.
INFO:tensorflow:SavedModel written to: b'/some/path/simple/saved_model.pb'
Ok
Restoring...
INFO:tensorflow:Restoring parameters from b'/some/path/simple/variables/variables'
Ok
Restored values: [-0.26331693 -0.13013336 -0.12553 -0.04276478 0.2933622 ]
Restored values: [-0.07730117 0.11119192 -0.20817074 -0.35660955 0.16990358]
Inferences match: True