经过机器学习生成的模型,可以判断英语的肯定或否定含义,减轻了人的工作量,使得对大量意见进行归集,判断成为可能
==>源代码Github下载
你可以逐行阅读源码和我的注释,然后运行感兴趣的Python文件,就可以让模型工作起来
性质 | 内容 | 详细信息 |
---|---|---|
源码 | Python文件4篇 | data_helpers.py |
- | - | train.py |
- | - | eval.py |
- | - | text_cnn.py |
数据集 | 训练测试数据 | rt-polarity.neg |
- | - | rt-polarity.pos |
import numpy as np
import re
import itertools
from collections import Counter
def clean_str(string):
#清理数据替换掉无词义的符号,这些符号,无法向量化
"""
Tokenization/string cleaning for all datasets except for SST.
Original taken from https://github.com/yoonkim/CNN_sentence/blob/master/process_data.py
"""
string = re.sub(r"[^A-Za-z0-9(),!?\'\`]", " ", string)
string = re.sub(r"\'s", " \'s", string)
string = re.sub(r"\'ve", " \'ve", string)
string = re.sub(r"n\'t", " n\'t", string)
string = re.sub(r"\'re", " \'re", string)
string = re.sub(r"\'d", " \'d", string)
string = re.sub(r"\'ll", " \'ll", string)
string = re.sub(r",", " , ", string)
string = re.sub(r"!", " ! ", string)
string = re.sub(r"\(", " \( ", string)
string = re.sub(r"\)", " \) ", string)
string = re.sub(r"\?", " \? ", string)
string = re.sub(r"\s{2,}", " ", string)
return string.strip().lower()
def load_data_and_labels(positive_data_file, negative_data_file):
# 将 词 和 标签,组成一个向量,维度是词,深度是2 positive和negative
# 正样本语料库词标签为[0,1]
# 负样本语料库词标签为[1,0]
"""
Loads MR polarity data from files, splits the data into words and generates labels.
Returns split sentences and labels.
"""
# Load data from files
positive_examples = list(open(positive_data_file, "r").readlines())
positive_examples = [s.strip() for s in positive_examples]
negative_examples = list(open(negative_data_file, "r").readlines())
negative_examples = [s.strip() for s in negative_examples]
# Split by words
x_text = positive_examples + negative_examples
x_text = [clean_str(sent) for sent in x_text]
# Generate labels
positive_labels = [[0, 1] for _ in positive_examples]
negative_labels = [[1, 0] for _ in negative_examples]
y = np.concatenate([positive_labels, negative_labels], 0)
return [x_text, y]
def batch_iter(data, batch_size, num_epochs, shuffle=True):
# 主要功能
# 1 选择每次迭代,是否洗数据,像洗牌意义
# 2 用生成器,每次只输出shuffled_data[start_index:end_index]这么多
"""
Generates a batch iterator for a dataset.
"""
data = np.array(data)
data_size = len(data)
num_batches_per_epoch = int((len(data)-1)/batch_size) + 1
for epoch in range(num_epochs):
# Shuffle the data at each epoch
if shuffle:
shuffle_indices = np.random.permutation(np.arange(data_size))
shuffled_data = data[shuffle_indices]
else:
shuffled_data = data
for batch_num in range(num_batches_per_epoch):
start_index = batch_num * batch_size
end_index = min((batch_num + 1) * batch_size, data_size)
yield shuffled_data[start_index:end_index]
#! /usr/bin/env python
import tensorflow as tf
import numpy as np
import os
import time
import datetime
import data_helpers
from text_cnn import TextCNN
from tensorflow.contrib import learn
# Parameters
# ==================================================
# 语料文件路径定义
# Data loading params
tf.flags.DEFINE_float("dev_sample_percentage", .1, "Percentage of the training data to use for validation")
tf.flags.DEFINE_string("positive_data_file", "./data/rt-polaritydata/rt-polarity.pos", "Data source for the positive data.")
tf.flags.DEFINE_string("negative_data_file", "./data/rt-polaritydata/rt-polarity.neg", "Data source for the negative data.")
# 模型关键参数定义,卷积想象成这样
#[1] [0] [0]
#[0] [1] [0]
#[0] [0] [1]
# 如上,类推3/4/5 ==>filter_sizes
# Model Hyperparameters
tf.flags.DEFINE_integer("embedding_dim", 128, "Dimensionality of character embedding (default: 128)")
tf.flags.DEFINE_string("filter_sizes", "3,4,5", "Comma-separated filter sizes (default: '3,4,5')")
tf.flags.DEFINE_integer("num_filters", 128, "Number of filters per filter size (default: 128)")
tf.flags.DEFINE_float("dropout_keep_prob", 0.5, "Dropout keep probability (default: 0.5)")
tf.flags.DEFINE_float("l2_reg_lambda", 0.0, "L2 regularization lambda (default: 0.0)")
# Training parameters
#每个数据集64个数据,就是一批数据
tf.flags.DEFINE_integer("batch_size", 64, "Batch Size (default: 64)")
#200个数据集
tf.flags.DEFINE_integer("num_epochs", 200, "Number of training epochs (default: 200)")
#每100个,测试一个数据集(batch)
tf.flags.DEFINE_integer("evaluate_every", 100, "Evaluate model on dev set after this many steps (default: 100)")
tf.flags.DEFINE_integer("checkpoint_every", 100, "Save model after this many steps (default: 100)")
tf.flags.DEFINE_integer("num_checkpoints", 5, "Number of checkpoints to store (default: 5)")
# Misc Parameters
tf.flags.DEFINE_boolean("allow_soft_placement", True, "Allow device soft device placement")
tf.flags.DEFINE_boolean("log_device_placement", False, "Log placement of ops on devices")
FLAGS = tf.flags.FLAGS
FLAGS._parse_flags()
print("\nParameters:")
for attr, value in sorted(FLAGS.__flags.items()):
print("{}={}".format(attr.upper(), value))
print("")
# Data Preparation
# ==================================================
# Load data
print("Loading data...")
x_text, y = data_helpers.load_data_and_labels(FLAGS.positive_data_file, FLAGS.negative_data_file)
# Build vocabulary
max_document_length = max([len(x.split(" ")) for x in x_text])
vocab_processor = learn.preprocessing.VocabularyProcessor(max_document_length)
x = np.array(list(vocab_processor.fit_transform(x_text)))
# Randomly shuffle data
# 打散数据,seed(10),生成固定随机数 0.57140259469
np.random.seed(10)
# np.arange 生成随机序列
shuffle_indices = np.random.permutation(np.arange(len(y)))
x_shuffled = x[shuffle_indices]
y_shuffled = y[shuffle_indices]
# Split train/test set
# TODO: This is very crude, should use cross-validation
# 直接把dev_sample_index前用于训练,dev_sample_index后的用于训练;
# 交叉验证更好,从测试结果看,准确率差不多;
dev_sample_index = -1 * int(FLAGS.dev_sample_percentage * float(len(y)))
x_train, x_dev = x_shuffled[:dev_sample_index], x_shuffled[dev_sample_index:]
y_train, y_dev = y_shuffled[:dev_sample_index], y_shuffled[dev_sample_index:]
print("Vocabulary Size: {:d}".format(len(vocab_processor.vocabulary_)))
print("Train/Dev split: {:d}/{:d}".format(len(y_train), len(y_dev)))
#前面都在准备数据
# Training
# ==================================================
#开始构造图
with tf.Graph().as_default():
session_conf = tf.ConfigProto(
allow_soft_placement=FLAGS.allow_soft_placement,
log_device_placement=FLAGS.log_device_placement)
sess = tf.Session(config=session_conf)
with sess.as_default():
#卷积池化网络导入
cnn = TextCNN(
sequence_length=x_train.shape[1],
num_classes=y_train.shape[1],
vocab_size=len(vocab_processor.vocabulary_),
embedding_size=FLAGS.embedding_dim,
filter_sizes=list(map(int, FLAGS.filter_sizes.split(","))),
num_filters=FLAGS.num_filters,
l2_reg_lambda=FLAGS.l2_reg_lambda)
#l2_reg_lambda 中文'拉姆那',正则化参数,这里用0
# Define Training procedure
global_step = tf.Variable(0, name="global_step", trainable=False)
# 目标函数小于时optimizer,训练结束
optimizer = tf.train.AdamOptimizer(1e-3)
# 导入cnn.loss求偏导的差(也就是结果的变化量),反过来就知道,上次的变化,对结果影响
# 从而知道是否到全局最优解
grads_and_vars = optimizer.compute_gradients(cnn.loss)
# 填入训练序列,后面会步进迭代
train_op = optimizer.apply_gradients(grads_and_vars, global_step=global_step)
# Keep track of gradient values and sparsity (optional)
grad_summaries = []
# 每一步都存参数,tensorboard可以看
for g, v in grads_and_vars:
if g is not None:
grad_hist_summary = tf.histogram_summary("{}/grad/hist".format(v.name), g)
sparsity_summary = tf.scalar_summary("{}/grad/sparsity".format(v.name), tf.nn.zero_fraction(g))
grad_summaries.append(grad_hist_summary)
grad_summaries.append(sparsity_summary)
grad_summaries_merged = tf.merge_summary(grad_summaries)
# Output directory for models and summaries
timestamp = str(int(time.time()))
# 文件名为时间
out_dir = os.path.abspath(os.path.join(os.path.curdir, "runs", timestamp))
print("Writing to {}\n".format(out_dir))
# Summaries for loss and accuracy
# 目标函数 和 准确率的参数保存
loss_summary = tf.scalar_summary("loss", cnn.loss)
acc_summary = tf.scalar_summary("accuracy", cnn.accuracy)
# Train Summaries
# 训练数据保存
train_summary_op = tf.merge_summary([loss_summary, acc_summary, grad_summaries_merged])
train_summary_dir = os.path.join(out_dir, "summaries", "train")
train_summary_writer = tf.train.SummaryWriter(train_summary_dir, sess.graph)
# Dev summaries
# 测试数据保存
dev_summary_op = tf.merge_summary([loss_summary, acc_summary])
dev_summary_dir = os.path.join(out_dir, "summaries", "dev")
dev_summary_writer = tf.train.SummaryWriter(dev_summary_dir, sess.graph)
# Checkpoint directory. Tensorflow assumes this directory already exists so we need to create it
checkpoint_dir = os.path.abspath(os.path.join(out_dir, "checkpoints"))
checkpoint_prefix = os.path.join(checkpoint_dir, "model")
if not os.path.exists(checkpoint_dir):
os.makedirs(checkpoint_dir)
saver = tf.train.Saver(tf.global_variables(), max_to_keep=FLAGS.num_checkpoints)
# Write vocabulary
vocab_processor.save(os.path.join(out_dir, "vocab"))
# Initialize all variables
sess.run(tf.global_variables_initializer())
def train_step(x_batch, y_batch):
# 训练每一步,填入数据
"""
A single training step
"""
feed_dict = {
cnn.input_x: x_batch,
cnn.input_y: y_batch,
cnn.dropout_keep_prob: FLAGS.dropout_keep_prob
}
_, step, summaries, loss, accuracy = sess.run(
[train_op, global_step, train_summary_op, cnn.loss, cnn.accuracy],
feed_dict)
time_str = datetime.datetime.now().isoformat()
print("{}: step {}, loss {:g}, acc {:g}".format(time_str, step, loss, accuracy))
train_summary_writer.add_summary(summaries, step)
def dev_step(x_batch, y_batch, writer=None):
# 测试每一步,填入数据
"""
Evaluates model on a dev set
"""
feed_dict = {
cnn.input_x: x_batch,
cnn.input_y: y_batch,
cnn.dropout_keep_prob: 1.0
}
step, summaries, loss, accuracy = sess.run(
[global_step, dev_summary_op, cnn.loss, cnn.accuracy],
feed_dict)
time_str = datetime.datetime.now().isoformat()
print("{}: step {}, loss {:g}, acc {:g}".format(time_str, step, loss, accuracy))
if writer:
writer.add_summary(summaries, step)
# Generate batches
batches = data_helpers.batch_iter(
list(zip(x_train, y_train)), FLAGS.batch_size, FLAGS.num_epochs)
# Training loop. For each batch...
for batch in batches:
x_batch, y_batch = zip(*batch)
train_step(x_batch, y_batch)
current_step = tf.train.global_step(sess, global_step)
if current_step % FLAGS.evaluate_every == 0:
# 每隔100次,测试一次
print("\nEvaluation:")
dev_step(x_dev, y_dev, writer=dev_summary_writer)
print("")
if current_step % FLAGS.checkpoint_every == 0:
# 每隔100次,存档一次
path = saver.save(sess, checkpoint_prefix, global_step=current_step)
print("Saved model checkpoint to {}\n".format(path))
#! /usr/bin/env python
import tensorflow as tf
import numpy as np
import os
import time
import datetime
import data_helpers
from text_cnn import TextCNN
from tensorflow.contrib import learn
import csv
# Parameters
# ==================================================
#数据路径,注意,相对路径是相对当前Python环境的运行路径而言
# Data Parameters
tf.flags.DEFINE_string("positive_data_file", "./data/rt-polaritydata/rt-polarity.pos", "Data source for the positive data.")
tf.flags.DEFINE_string("negative_data_file", "./data/rt-polaritydata/rt-polarity.neg", "Data source for the positive data.")
# Eval Parameters
# batch_size=一批数据有多少 checkpoint_dir=存档路径 eval_train=开关是评价还是训练
tf.flags.DEFINE_integer("batch_size", 64, "Batch Size (default: 64)")
tf.flags.DEFINE_string("checkpoint_dir", "", "Checkpoint directory from training run")
tf.flags.DEFINE_boolean("eval_train", False, "Evaluate on all training data")
# Misc Parameters
# allow_soft_placement=软约束,就是运算设备不存在系统指定一个
# log_device_placement=记录设备信息,被指派另一个,要不要记录下来信息
tf.flags.DEFINE_boolean("allow_soft_placement", True, "Allow device soft device placement")
tf.flags.DEFINE_boolean("log_device_placement", False, "Log placement of ops on devices")
FLAGS = tf.flags.FLAGS
FLAGS._parse_flags()
print("\nParameters:")
for attr, value in sorted(FLAGS.__flags.items()):
print("{}={}".format(attr.upper(), value))
print("")
# CHANGE THIS: Load data. Load your own data here
# eval_train上面开关设置了false走else,测试一条,一正一负,如果为真,走自己的测试样本
if FLAGS.eval_train:
x_raw, y_test = data_helpers.load_data_and_labels(FLAGS.positive_data_file, FLAGS.negative_data_file)
y_test = np.argmax(y_test, axis=1)
else:
x_raw = ["a masterpiece four years in the making", "everything is off."]
y_test = [1, 0]
# Map data into vocabulary
# 词向量存放路径并取出,词向量就是打开模型这台车的钥匙
vocab_path = os.path.join(FLAGS.checkpoint_dir, "..", "vocab")
vocab_processor = learn.preprocessing.VocabularyProcessor.restore(vocab_path)
# 测试语料,写入一个array,依次串行写入
x_test = np.array(list(vocab_processor.transform(x_raw)))
print("\nEvaluating...\n")
# Evaluation
# ==================================================
# 找到最新的时间点,应用模型
checkpoint_file = tf.train.latest_checkpoint(FLAGS.checkpoint_dir)
# 构造图,就是运算结构,构造好了,填入数据,连续迭代
graph = tf.Graph()
with graph.as_default():
session_conf = tf.ConfigProto(
allow_soft_placement=FLAGS.allow_soft_placement,
log_device_placement=FLAGS.log_device_placement)
sess = tf.Session(config=session_conf)
# 打开会话,准备传入构造好的graph,交给后台运算
with sess.as_default():
# Load the saved meta graph and restore variables
saver = tf.train.import_meta_graph("{}.meta".format(checkpoint_file))
saver.restore(sess, checkpoint_file)
# Get the placeholders from the graph by name
input_x = graph.get_operation_by_name("input_x").outputs[0]
# input_y = graph.get_operation_by_name("input_y").outputs[0]
dropout_keep_prob = graph.get_operation_by_name("dropout_keep_prob").outputs[0]
# Tensors we want to evaluate
predictions = graph.get_operation_by_name("output/predictions").outputs[0]
# 以上分别为保存,输出 输入占位符 的设置
# Generate batches for one epoch
# 取batches,每FLAGS.batch_size个list(x_test),作一个bastch
batches = data_helpers.batch_iter(list(x_test), FLAGS.batch_size, 1, shuffle=False)
# Collect the predictions here
# 判断输出,用来和标签比对,即知道正确率,见下
all_predictions = []
for x_test_batch in batches:
batch_predictions = sess.run(predictions, {input_x: x_test_batch, dropout_keep_prob: 1.0})
all_predictions = np.concatenate([all_predictions, batch_predictions])
# 循环相连接,把所有的x_test_batch跑出来的结果x_test_batch,首尾相连
# dropout_keep_prob=1.0 不损失
# Print accuracy if y_test is defined
if y_test is not None:
correct_predictions = float(sum(all_predictions == y_test))
print("Total number of test examples: {}".format(len(y_test)))
print("Accuracy: {:g}".format(correct_predictions/float(len(y_test))))
# y_test=所有的标签,correct_predictions=正确率求和,两者求商,为正确率
# Save the evaluation to a csv
# 准备数据,存入该路径下的prediction.csv文件
predictions_human_readable = np.column_stack((np.array(x_raw), all_predictions))
out_path = os.path.join(FLAGS.checkpoint_dir, "..", "prediction.csv")
print("Saving evaluation to {0}".format(out_path))
with open(out_path, 'w') as f:
csv.writer(f).writerows(predictions_human_readable)
#excel打开可见
import tensorflow as tf
import numpy as np
# 本类是CNN网络实现
class TextCNN(object):
"""
A CNN for text classification.
Uses an embedding layer, followed by a convolutional, max-pooling and softmax layer.
"""
def __init__(
# 参数,写记名字,可以理解部分意思;
self, sequence_length, num_classes, vocab_size,
embedding_size, filter_sizes, num_filters, l2_reg_lambda=0.0):
# Placeholders for input, output and dropout
# 数据入口
# input_x 输入语料,待训练的内容,维度是sequence_length,"N个词构成的N维向量";
# input_y 输入语料,待训练的内容标签,维度是num_classes,"正面 || 负面";
# dropout_keep_prob dropout参数,防止过拟合,仅在训练时用;
self.input_x = tf.placeholder(tf.int32, [None, sequence_length], name="input_x")
self.input_y = tf.placeholder(tf.float32, [None, num_classes], name="input_y")
self.dropout_keep_prob = tf.placeholder(tf.float32, name="dropout_keep_prob")
# Keeping track of l2 regularization loss (optional)
# 损失函数,就是训练的目标函数,初始化,训练的目的,就是偏导求解概率向量矩阵,趋近损失函数最小值;
# 交叉熵
l2_loss = tf.constant(0.0)
# Embedding layer
# 指定运算结构的运行位置在cpu非gpu,因为"embedding"无法运行在gpu.原因为深入理解
# 通过tf.name_scope指定"embedding"
with tf.device('/cpu:0'), tf.name_scope("embedding"):
# 表达"词向量宽度 和 嵌入深度"的概率矩阵 W,在-1~1间,线性随机赋初值;
# random_uniform 随机赋值
W = tf.Variable(
tf.random_uniform([vocab_size, embedding_size], -1.0, 1.0),
name="W")
# embedding_lookup=以input_x为索引,提取出W向量中的第(m=input_x)个维度
self.embedded_chars = tf.nn.embedding_lookup(W, self.input_x)
# expand_dims=增加维度,-1=插入一列,embedded_chars作为一列,插入embedded_chars_expanded
self.embedded_chars_expanded = tf.expand_dims(self.embedded_chars, -1)
# Create a convolution + maxpool layer for each filter size
# pooled_outputs=输出
pooled_outputs = []
# filter_sizes卷积核尺寸,枚举后遍历;
for i, filter_size in enumerate(filter_sizes):
# 命名空间,conv-maxpool-%s,卷积池化空间,也是运算结构的第二层
with tf.name_scope("conv-maxpool-%s" % filter_size):
# Convolution Layer
# 卷积滤波参数配置,不同的卷积核尺寸,提取不同的上下文特征,越宽=提取的上下文越长
filter_shape = [filter_size, embedding_size, 1, num_filters]
# 初始化W为方差0.1的正态分布
# 注意embedding层的W概率矩阵初始化为线性
# 原因在于,运算后反向传递的误差参数,符合正态分布,可以更好地趋近特征;
# 理解:类似于两个霰弹枪对射,弹丸容易对撞而发现重合区域,步枪对射,很难发现;
W = tf.Variable(tf.truncated_normal(filter_shape, stddev=0.1), name="W")
# 补偿系数b赋常量
b = tf.Variable(tf.constant(0.1, shape=[num_filters]), name="b")
# 开始卷积
conv = tf.nn.conv2d(
# 运算数据
self.embedded_chars_expanded,
# 概率矩阵
W,
# 卷积核参数
strides=[1, 1, 1, 1],
padding="VALID",
name="conv")
# Apply nonlinearity
# 激活函数,用的Relu,让显著地越显著
# 可以理解为,正面或者负面评价有一些标志词汇,这些词汇概率被增强\
# 即一旦出现这些词汇,倾向性分类进正或负面评价,该激励函数可加快学习进度\
# 增加稀疏性,因为让确定的事情更确定,噪声的影响就降到了最低,举一个例子\
# 语料样本中含有多次出现的"否定"意义的词,则其他词语误导判断的机会下降
h = tf.nn.relu(tf.nn.bias_add(conv, b), name="relu")
# Maxpooling over the outputs
#继续池化
pooled = tf.nn.max_pool(
h,
ksize=[1, sequence_length - filter_size + 1, 1, 1],
strides=[1, 1, 1, 1],
padding='VALID',
name="pool")
pooled_outputs.append(pooled)
# Combine all the pooled features
num_filters_total = num_filters * len(filter_sizes)
self.h_pool = tf.concat(3, pooled_outputs)
# 池化后的输出,维度为[hpool, num_filters_total]
# 最开始扁平的数据,体积上变成了细长的数据,有更多的特征和联系
# 由词的判定,引入上下文的判定,越多的特征,越多维度的概率矩阵,意味着越准确
self.h_pool_flat = tf.reshape(self.h_pool, [-1, num_filters_total])
# Add dropout
with tf.name_scope("dropout"):
# drop层,防止过拟合,参数之前给出dropout_keep_prob
# 互联网级别的数据无需过拟合,也就是大数据,因为过拟合的本质是采样失真,噪声权重影响了判断\
# 如果采样足够多,足够充分,噪声的影响可以被量化到趋近事实,也就无从过拟合\
# 举一个例子,历史课上爱发言的孩子,给历史老师留下印象爱发言,这就容易造成过拟合.\
# 如果班主任,天天观察孩子,记录下每一次发言的频度和持续时间,就能得出准确的结论,因为\
# 观察偏差样本偏差这些噪声都无法影响海量的准确采样\
# 结论:数据越大,drop和正则化就越不需要;
self.h_drop = tf.nn.dropout(self.h_pool_flat, self.dropout_keep_prob)
# Final (unnormalized) scores and predictions
# 输出层
with tf.name_scope("output"):
# 提取出所有节点的w和b
W = tf.get_variable(
"W",
shape=[num_filters_total, num_classes],
initializer=tf.contrib.layers.xavier_initializer())
b = tf.Variable(tf.constant(0.1, shape=[num_classes]), name="b")
# 损失函数导入
l2_loss += tf.nn.l2_loss(W)
l2_loss += tf.nn.l2_loss(b)
# 简单求和
self.scores = tf.nn.xw_plus_b(self.h_drop, W, b, name="scores")
# 归一化,把180:20的总得分,转化成90%和10%的概率
self.predictions = tf.argmax(self.scores, 1, name="predictions")
# CalculateMean cross-entropy loss
# 目标/损失函数,用的最小交叉熵
with tf.name_scope("loss"):
losses = tf.nn.softmax_cross_entropy_with_logits(self.scores, self.input_y)
self.loss = tf.reduce_mean(losses) + l2_reg_lambda * l2_loss
# Accuracy
with tf.name_scope("accuracy"):
# 准确率,简单求和算数平均值
correct_predictions = tf.equal(self.predictions, tf.argmax(self.input_y, 1))
self.accuracy = tf.reduce_mean(tf.cast(correct_predictions, "float"), name="accuracy")
为方便打开,转成txt文件
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