4

我使用张量流 0.9。
我想保存我的模型然后恢复它。
我只需添加tf.train.Saver()以保存和恢复我的训练变量。

这是我的代码:

import tensorflow as tf
import input_data
import os

checkpoint_dir='./ckpt_dir/'

mnist = input_data.read_data_sets("MNIST_data", one_hot = True)

x = tf.placeholder(tf.float32, shape = [None , 784])
y_ = tf.placeholder(tf.float32, [None, 10])

sess = tf.InteractiveSession()

def load_model(sess, saver, checkpoint_dir ):

ckpt = tf.train.get_checkpoint_state(checkpoint_dir)
if ckpt and ckpt.model_checkpoint_path:
print(ckpt.model_checkpoint_path)

saver.restore(sess, ckpt.model_checkpoint_path)

else:
if not os.path.exists(checkpoint_dir):
os.makedirs(checkpoint_dir)
sess.run(init)
return

def weight_variable(shape):
initial = tf.truncated_normal(shape, stddev = 0.1)
return tf.Variable(initial)

def bias_variable(shape):
initial = tf.constant(0.1, shape= shape)
return tf.Variable(initial)

def conv2d(x, W):
return tf.nn.conv2d(x, W, strides = [1, 1, 1, 1], padding = "SAME")

def max_pool_2x2(x):
return tf.nn.max_pool(x, ksize = [1, 2, 2, 1], strides = [1, 2, 2, 1],
padding = "SAME")

W_conv1 = weight_variable([5, 5, 1, 32])
b_conv1 = bias_variable([32])

x_image = tf.reshape(x, [-1, 28, 28, 1])

#
h_conv1 = tf.nn.relu(conv2d(x_image, W_conv1))
h_pool1 = max_pool_2x2(h_conv1)

#
W_conv2 = weight_variable([5, 5, 32, 64])
b_conv2 = bias_variable([64])

h_conv2 = tf.nn.relu(conv2d(h_pool1, W_conv2))
h_pool2 = max_pool_2x2(h_conv2)

W_fc1 = weight_variable([7764, 1024])
b_fc1 = bias_variable([1024])

h_pool2_flat = tf.reshape(h_pool2, [-1, 7764])
h_fc1 = tf.nn.relu(tf.matmul(h_pool2_flat, W_fc1) + b_fc1)

#
keep_prob = tf.placeholder(tf.float32)
h_fc1_drop = tf.nn.dropout(h_fc1, keep_prob)

#
W_fc2 = weight_variable([1024, 10])
b_fc2 = bias_variable([10])

y_conv = tf.nn.softmax(tf.matmul(h_fc1_drop,W_fc2) +b_fc2)

#
cross_entropy = tf.reduce_mean(-tf.reduce_sum(y_ * tf.log(y_conv), reduction_indices = [1]))
train_step = tf.train.AdamOptimizer(1e-4).minimize(cross_entropy)

correct_prediction = tf.equal(tf.argmax(y_conv, 1), tf.argmax(y_, 1))
accuracy = tf.reduce_mean(tf.cast(correct_prediction, tf.float32))

init = tf.initialize_all_variables()

saver = tf.train.Saver()

load_model(sess, saver, checkpoint_dir)

for i in range(1):
batch = mnist.train.next_batch(50)
if i%10 == 0:
train_accuracy = accuracy.eval(feed_dict = {x : batch[0] , y_ : batch[1], keep_prob : 1.0})
print("step %d, training accuracy %g"%(i, train_accuracy))

train_step.run(feed_dict = {x : batch[0], y_ : batch[1], keep_prob : 0.5})
print("test accuracy %g"%accuracy.eval(feed_dict={
x: mnist.test.images, y_: mnist.test.labels, keep_prob: 1.0}))

tf.scalar_summary("accuracy", accuracy)

saver.save(sess,checkpoint_dir+'model.ckpt')

当我恢复检查点时:

saver.restore(sess, ckpt.model_checkpoint_path)

TensorFlow 抛出此错误:

Traceback (most recent call last):
.
.
.
NotFoundError: Tensor name "global_step_7" not found in checkpoint files ./ckpt_dir/model.ckpt-0
[[Node: save_18/restore_slice_438 = RestoreSlicedt=DT_INT32, preferred_shard=-1, _device="/job:localhost/replica:0/task:0/cpu:0"]]
Caused by op 'save_18/restore_slice_438', defined at:
File "/home/m/anaconda3/lib/python3.5/site-packages/spyderlib/widgets/externalshell/start_ipython_kernel.py", line 205, in
ipythonkernel.start()
.
.
.
File "/home/m/anaconda3/lib/python3.5/site-packages/tensorflow/python/framework/ops.py", line 1224, in __init
raise TypeError("Control input must be an Operation, "

编辑:

我用蟒蛇。我第一次使用“run filename.py”在 spyder 或 ipython 中运行此代码时,它会将模型保存在检查点中,但是当我再次运行此代码时,它会引发错误。

但是当我关闭 spyder 或 ipython 时,再次打开它并运行它可以正确恢复检查点的代码。

此外,当我在终端“python filename.py”中运行时,它总是运行并且不会抛出任何错误。

4

1 回答 1

5

当您再次运行该文件时,您需要在调用开始时重置默认图表。


如果您不重置默认图表,并运行两次该行:

x = tf.Variable(1, name='x')
print x.name

您将看到第一次x有 name"x:0"而第二次看到它的 name 是"x_1:0"。这是令人困惑的tf.train.Saver

  • 它首先保存x使用名称的值"x:0"
  • 然后在下一次运行中尝试加载 的保存值x,但现在变量的名称是"x_1:0",因此保护程序尝试加载名称下的保存值"x_1:0"但找不到它,并返回错误。

但是,您可以在开始时使用 重置默认图表tf.reset_default_graph()。这将创建一个空图并将其用作默认图。
这两个图中的名称x可以相同:

# First run
tf.reset_default_graph()
x = tf.Variable(1, name='x')
print x.name  # prints 'x:0'

# Next run
tf.reset_default_graph()
x = tf.Variable(1, name='x')
print x.name  # prints 'x:0'

这两个变量现在可以具有相同的名称,因为它们不再位于同一个图中。


另一种方法是在开始时创建一个图形并将其用作默认图形:

graph = tf.Graph()
with graph.as_default():
    x = tf.Variable(1, name='x')
于 2016-06-29T08:04:17.207 回答