我真的是一个有张量流动的初学者，而且在所有这一领域，但我已经看过安德烈·卡尔帕西在CS231n课堂上的所有讲座，所以我对这段代码有所了解。
所以这是代码（不是我的代码）：https://github.com/nfmcclure/tensorflow_cookbook/tree/master/09_Recurrent_Neural_Networks/02_Implementing_RNN_for_Spam_Prediction
# Implementing an RNN in TensorFlow
# ----------------------------------
#
# We implement an RNN in TensorFlow to predict spam/ham from texts
#
# https://github.com/nfmcclure/tensorflow_cookbook/blob/master/09_Recurrent_Neural_Networks/02_Implementing_RNN_for_Spam_Prediction/02_implementing_rnn.py
import os
import re
import io
import glob
import requests
import numpy as np
import matplotlib.pyplot as plt
import tensorflow as tf
from zipfile import ZipFile
from tensorflow.python.framework import ops
ops.reset_default_graph()
# Start a graph
sess = tf.Session()
# Set RNN parameters
epochs = 20
batch_size = 250
max_sequence_length = 25
rnn_size = 10
embedding_size = 50
min_word_frequency = 10
learning_rate = 0.0005
dropout_keep_prob = tf.placeholder(tf.float32)
# Download or open data
data_dir = 'temp'
data_file = 'text_data.txt'
if not os.path.exists(data_dir):
os.makedirs(data_dir)
if not os.path.isfile(os.path.join(data_dir, data_file)):
zip_url = 'http://archive.ics.uci.edu/ml/machine-learning-databases/00228/smsspamcollection.zip'
r = requests.get(zip_url)
z = ZipFile(io.BytesIO(r.content))
file = z.read('SMSSpamCollection')
# Format Data
text_data = file.decode()
text_data = text_data.encode('ascii', errors='ignore')
text_data = text_data.decode().split('\n')
# Save data to text file
with open(os.path.join(data_dir, data_file), 'w') as file_conn:
for text in text_data:
file_conn.write("{}\n".format(text))
else:
# Open data from text file
text_data = []
with open(os.path.join(data_dir, data_file), 'r') as file_conn:
for row in file_conn:
text_data.append(row)
text_data = text_data[:-1]
text_data = [x.split('\t') for x in text_data if len(x) >= 1]
text_data = [x for x in text_data if len(x) > 1]
print([list(x) for x in zip(*text_data)])
[text_data_target, text_data_train] = [list(x) for x in zip(*text_data)]
# Create a text cleaning function
def clean_text(text_string):
text_string = re.sub(r'([^\s\w]|_|[0-9])+', '', text_string)
text_string = " ".join(text_string.split())
text_string = text_string.lower()
return (text_string)
# Clean texts
text_data_train = [clean_text(x) for x in text_data_train]
# Change texts into numeric vectors
vocab_processor = tf.contrib.learn.preprocessing.VocabularyProcessor(max_sequence_length,
min_frequency=min_word_frequency)
text_processed = np.array(list(vocab_processor.fit_transform(text_data_train)))
# Shuffle and split data
text_processed = np.array(text_processed)
text_data_target = np.array([1 if x == 'ham' else 0 for x in text_data_target])
shuffled_ix = np.random.permutation(np.arange(len(text_data_target)))
x_shuffled = text_processed[shuffled_ix]
y_shuffled = text_data_target[shuffled_ix]
# Split train/test set
ix_cutoff = int(len(y_shuffled) * 0.80)
x_train, x_test = x_shuffled[:ix_cutoff], x_shuffled[ix_cutoff:]
y_train, y_test = y_shuffled[:ix_cutoff], y_shuffled[ix_cutoff:]
vocab_size = len(vocab_processor.vocabulary_)
print("Vocabulary Size: {:d}".format(vocab_size))
print("80-20 Train Test split: {:d} -- {:d}".format(len(y_train), len(y_test)))
# Create placeholders
x_data = tf.placeholder(tf.int32, [None, max_sequence_length])
y_output = tf.placeholder(tf.int32, [None])
# Create embedding
embedding_mat = tf.Variable(tf.random_uniform([vocab_size, embedding_size], -1.0, 1.0))
embedding_output = tf.nn.embedding_lookup(embedding_mat, x_data)
# embedding_output_expanded = tf.expand_dims(embedding_output, -1)
# Define the RNN cell
# tensorflow change >= 1.0, rnn is put into tensorflow.contrib directory. Prior version not test.
if tf.__version__[0] >= '1':
cell = tf.contrib.rnn.BasicRNNCell(num_units=rnn_size)
else:
cell = tf.nn.rnn_cell.BasicRNNCell(num_units=rnn_size)
output, state = tf.nn.dynamic_rnn(cell, embedding_output, dtype=tf.float32)
output = tf.nn.dropout(output, dropout_keep_prob)
# Get output of RNN sequence
output = tf.transpose(output, [1, 0, 2])
last = tf.gather(output, int(output.get_shape()[0]) - 1)
weight = tf.Variable(tf.truncated_normal([rnn_size, 2], stddev=0.1))
bias = tf.Variable(tf.constant(0.1, shape=[2]))
logits_out = tf.matmul(last, weight) + bias
# Loss function
losses = tf.nn.sparse_softmax_cross_entropy_with_logits(logits=logits_out,
labels=y_output) # logits=float32, labels=int32
loss = tf.reduce_mean(losses)
accuracy = tf.reduce_mean(tf.cast(tf.equal(tf.argmax(logits_out, 1), tf.cast(y_output, tf.int64)), tf.float32))
optimizer = tf.train.RMSPropOptimizer(learning_rate)
train_step = optimizer.minimize(loss)
init = tf.global_variables_initializer()
sess.run(init)
train_loss = []
test_loss = []
train_accuracy = []
test_accuracy = []
# Start training
for epoch in range(epochs):
# Shuffle training data
shuffled_ix = np.random.permutation(np.arange(len(x_train)))
x_train = x_train[shuffled_ix]
y_train = y_train[shuffled_ix]
num_batches = int(len(x_train) / batch_size) + 1
# TO DO CALCULATE GENERATIONS ExACTLY
for i in range(num_batches):
# Select train data
min_ix = i * batch_size
max_ix = np.min([len(x_train), ((i + 1) * batch_size)])
x_train_batch = x_train[min_ix:max_ix]
y_train_batch = y_train[min_ix:max_ix]
# Run train step
train_dict = {x_data: x_train_batch, y_output: y_train_batch, dropout_keep_prob: 0.5}
sess.run(train_step, feed_dict=train_dict)
# Run loss and accuracy for training
temp_train_loss, temp_train_acc = sess.run([loss, accuracy], feed_dict=train_dict)
train_loss.append(temp_train_loss)
train_accuracy.append(temp_train_acc)
# Run Eval Step
test_dict = {x_data: x_test, y_output: y_test, dropout_keep_prob: 1.0}
temp_test_loss, temp_test_acc = sess.run([loss, accuracy], feed_dict=test_dict)
test_loss.append(temp_test_loss)
test_accuracy.append(temp_test_acc)
print('Epoch: {}, Test Loss: {:.2}, Test Acc: {:.2}'.format(epoch + 1, temp_test_loss, temp_test_acc))
# Plot loss over time
epoch_seq = np.arange(1, epochs + 1)
plt.plot(epoch_seq, train_loss, 'k--', label='Train Set')
plt.plot(epoch_seq, test_loss, 'r-', label='Test Set')
plt.title('Softmax Loss')
plt.xlabel('Epochs')
plt.ylabel('Softmax Loss')
plt.legend(loc='upper left')
plt.show()
# Plot accuracy over time
plt.plot(epoch_seq, train_accuracy, 'k--', label='Train Set')
plt.plot(epoch_seq, test_accuracy, 'r-', label='Test Set')
plt.title('Test Accuracy')
plt.xlabel('Epochs')
plt.ylabel('Accuracy')
plt.legend(loc='upper left')
plt.show()
def findFiles(path): return glob.glob(path)
pred_array = "words"
pred_num = np.array(list(vocab_processor.fit_transform(pred_array)))
print(pred_num)
pred_output = tf.placeholder(tf.float32,[1,len(pred_array),max_sequence_length])
feed_dict = {pred_output: [pred_num]}
classification = sess.run(losses, feed_dict)
print(classification)
它是一个RNN垃圾邮件分类器，并且工作得很好（接受我在最后编写的部分，我试图创建预测）。
我只是想了解如何为此创建预测函数，看起来像这样：
def predict(text): # text is a string (my mail)
# Doing prediction stuff
return (top result) # ham or spam
最后几行是我最后一次尝试给出了以下错误：
tensorflow.python.framework.errors_impl.InvalidArgumentError: You must feed a value for placeholder tensor 'Placeholder' with dtype float
[[Node: Placeholder = Placeholder[dtype=DT_FLOAT, shape=<unknown>, _device="/job:localhost/replica:0/task:0/cpu:0"]()]]
此外，我尝试使用Making predictions with a TensorFlow model做一些事情，并且我也阅读https://www.tensorflow.org/serving/serving_basic并且我尝试过的所有事情都失败了......
由于我只是初学者的解释受到欢迎，但我不确定我是否知道如何编码，所以你也可以发布代码答案。
（Python 3.6 btw）
谢谢！
答案 0 :(得分：1)
如果您看一下原始代码如何处理培训和测试步骤，特别是他们如何设置train_dict和test_dict，您会看到它们为定义为{{的每个张量提供值1}}在图表中。基本上占位符需要被赋予一些价值，如果它们将用于您要求网络进行的任何计算中。由于您正在寻找来自网络的预测，因此您可能不需要提供预期的输出，但您需要为其提供输入数据placeholder和x_data的值。这应该是dropout_keep_prob用于预测。
您还需要预测，而不是丢失网络。损失基本上衡量的是您的网络输出与您的预期相差多少，但由于您试图预测新数据的某些内容，您实际上只是希望看到网络所说的内容。您可以直接使用dropout_keep_prob=1.0 op执行此操作，或者我们可以添加一个操作，将您的logits转换为类的概率分布。无论哪种方式，您都可以查看分布，以了解网络认为您的数据落入每个类别的可能性，或者您可以将此向量的最大值设置为输出网络的最佳猜测。
所以你可能会尝试类似的东西：
logits_out