Tensorflow Estimator API:摘要

Question

我无法实现使用Tensorflow的Estimator API进行摘要.

Estimator类非常有用,原因很多:我已经实现了自己的类,它们非常相似,但我试图切换到这个类.

这是代码示例:

import tensorflow as tf
import tensorflow.contrib.layers as layers
import tensorflow.contrib.learn as learn
import numpy as np

 # To reproduce the error: docker run --rm -w /algo -v $(pwd):/algo tensorflow/tensorflow bash -c "python sample.py"

def model_fn(x, y, mode):
    logits = layers.fully_connected(x, 12, scope="dense-1")
    logits = layers.fully_connected(logits, 56, scope="dense-2")
    logits = layers.fully_connected(logits, 4, scope="dense-3")

    loss = tf.reduce_mean(tf.nn.sparse_softmax_cross_entropy_with_logits(logits=logits, labels=y), name="xentropy")

    return {"predictions":logits}, loss, tf.train.AdamOptimizer(0.001).minimize(loss)


def input_fun():
    """ To be completed for a 4 classes classification problem """

    feature = tf.constant(np.random.rand(100,10))
    labels = tf.constant(np.random.random_integers(0,3, size=(100,)))

    return feature, labels

estimator = learn.Estimator(model_fn=model_fn, )

trainingConfig = tf.contrib.learn.RunConfig(save_checkpoints_secs=60)

estimator = learn.Estimator(model_fn=model_fn, model_dir="./tmp", config=trainingConfig)

# Works
estimator.fit(input_fn=input_fun, steps=2)

# The following code does not work

# Can't initialize saver

# saver = tf.train.Saver(max_to_keep=10) # Error: No variables to save

# The following fails because I am missing a saver... :(

hooks=[
        tf.train.LoggingTensorHook(["xentropy"], every_n_iter=100),
        tf.train.CheckpointSaverHook("./tmp", save_steps=1000, checkpoint_basename='model.ckpt'),
        tf.train.StepCounterHook(every_n_steps=100, output_dir="./tmp"),
        tf.train.SummarySaverHook(save_steps=100, output_dir="./tmp"),
]

estimator.fit(input_fn=input_fun, steps=2, monitors=hooks)

正如您所看到的,我可以创建一个Estimator并使用它,但我可以实现为拟合过程添加钩子.

日志挂钩工作正常,但其他需要张量和保护程序,我无法提供.

张量在模型函数中定义,因此我无法将它们传递给SummaryHook,并且无法初始化Saver,因为没有张量可以保存...

我的问题有解决方案吗？(我猜是的,但在tensorflow文档中缺少此部分的文档)

• 我如何初始化我的保护程序？或者我应该使用其他物品,如脚手架？
• 如何将摘要传递给SummaryHook,因为它们是在我的模型函数中定义的？

提前致谢.

PS:我已经看过DNNClassifier API,但我想使用Convolutional Nets和其他人的估算器API.我需要为任何估算器创建摘要.

Answer 1

预期的用例是让Estimator为您保存摘要.RunConfig中有一些选项用于配置摘要写入.构造Estimator时会传递RunConfigs .