Question

我是Python和TensorFlow的新手，我试图在TensorFlow中使用假数据构建一个简单的工作示例。我的目标是使用DNNRegressor估计器从多维输入中预测实际值。这是我写的代码：

import pandas as pd
import tensorflow as tf
import numpy as np

# Amount of train samples
m_train = 1000
# Amount of test samples
m_test = 100
# Dimensions for each sample
n = 10

def from_dataset(ds):
   return lambda: ds.make_one_shot_iterator().get_next()

# Create random samples with numpy
train_data = (np.random.sample((m_train,n)), np.random.sample((m_train,1)))
test_data = (np.random.sample((m_test,n)), np.random.sample((m_test,1)))

# Create two datasets, one for trainning and the other for testing
train_dataset = tf.data.Dataset.from_tensor_slices(train_data)
test_dataset = tf.data.Dataset.from_tensor_slices(test_data)

feature_columns = [tf.contrib.layers.real_valued_column("", dimension=n)]

model = tf.estimator.DNNRegressor(hidden_units=[20, 20], feature_columns=feature_columns)

# Train the model
model.train(input_fn=from_dataset(train_dataset), steps=1000)

# Evaluate the unseen samples
eval_result = model.evaluate(input_fn=from_dataset(test_dataset))

这是我得到的错误：

$ python fake.py 
WARNING:tensorflow:Using temporary folder as model directory: /tmp/tmp1j5irF
Traceback (most recent call last):
  File "fake.py", line 28, in <module>
    model.train(input_fn=from_dataset(train_dataset), steps=1000)
  File "/usr/lib/python2.7/site-packages/tensorflow/python/estimator/estimator.py", line 314, in train
    loss = self._train_model(input_fn, hooks, saving_listeners)
  File "/usr/lib/python2.7/site-packages/tensorflow/python/estimator/estimator.py", line 743, in _train_model
    features, labels, model_fn_lib.ModeKeys.TRAIN, self.config)
  File "/usr/lib/python2.7/site-packages/tensorflow/python/estimator/estimator.py", line 725, in _call_model_fn
    model_fn_results = self._model_fn(features=features, **kwargs)
  File "/usr/lib/python2.7/site-packages/tensorflow/python/estimator/canned/dnn.py", line 448, in _model_fn
    config=config)
  File "/usr/lib/python2.7/site-packages/tensorflow/python/estimator/canned/dnn.py", line 153, in _dnn_model_fn
    'Given type: {}'.format(type(features)))
ValueError: features should be a dictionary of `Tensor`s. Given type: <class 'tensorflow.python.framework.ops.Tensor'>

我想说我必须使用Tensors字典，但我刚刚开始使用Python而且我不知道如何去做。

Answer 1

您需要返回get_one（）返回的迭代器，而不是返回迭代器的lambda函数。查看https://github.com/tensorflow/tensorflow/blob/r1.8/tensorflow/examples/get_started/regression/dnn_regression.py

使用TensorFlow的最小DNNRegressor示例

1 个答案: