/**
* 训练
*
* @throws Exception
*/
public void train() throws Exception {
// 建立字典管理器
Pipe lpipe = new Target2Label(al);
Pipe fpipe = new StringArray2IndexArray(factory, true);
// 构造转换器组
SeriesPipes pipe = new SeriesPipes(new Pipe[] {lpipe, fpipe});
InstanceSet instset = new InstanceSet(pipe, factory);
instset.loadThruStagePipes(new SimpleFileReader(trainFile, " ", true, Type.LabelData));
Generator gen = new SFGenerator();
ZeroOneLoss l = new ZeroOneLoss();
Inferencer ms = new LinearMax(gen, factory.getLabelSize());
Update update = new LinearMaxPAUpdate(l);
OnlineTrainer trainer = new OnlineTrainer(ms, update, l, factory, 50, 0.005f);
Linear pclassifier = trainer.train(instset, instset);
pipe.removeTargetPipe();
pclassifier.setPipe(pipe);
factory.setStopIncrement(true);
pclassifier.saveTo(modelFile);
}
public static void main(String[] args) throws Exception {
// 建立字典管理器
AlphabetFactory af = AlphabetFactory.buildFactory();
// 使用n元特征
Pipe ngrampp = new NGram(new int[] {2, 3});
// 将字符特征转换成字典索引
Pipe indexpp = new StringArray2IndexArray(af);
// 将目标值对应的索引号作为类别
Pipe targetpp = new Target2Label(af.DefaultLabelAlphabet());
// 建立pipe组合
SeriesPipes pp = new SeriesPipes(new Pipe[] {ngrampp, targetpp, indexpp});
InstanceSet instset = new InstanceSet(pp, af);
// 用不同的Reader读取相应格式的文件
Reader reader = new FileReader(trainDataPath, "UTF-8", ".data");
// 读入数据，并进行数据处理
instset.loadThruStagePipes(reader);
float percent = 0.8f;
// 将数据集分为训练是和测试集
InstanceSet[] splitsets = instset.split(percent);
InstanceSet trainset = splitsets[0];
InstanceSet testset = splitsets[1];
/** 建立分类器 */
OnlineTrainer trainer = new OnlineTrainer(af);
Linear pclassifier = trainer.train(trainset);
pp.removeTargetPipe();
pclassifier.setPipe(pp);
af.setStopIncrement(true);
// 将分类器保存到模型文件
pclassifier.saveTo(modelFile);
pclassifier = null;
// 从模型文件读入分类器
Linear cl = Linear.loadFrom(modelFile);
// 性能评测
Evaluation eval = new Evaluation(testset);
eval.eval(cl, 1);
/** 测试 */
System.out.println("类别 : 文本内容");
System.out.println("===================");
for (int i = 0; i < testset.size(); i++) {
Instance data = testset.getInstance(i);
Integer gold = (Integer) data.getTarget();
String pred_label = cl.getStringLabel(data);
String gold_label = cl.getLabel(gold);
if (pred_label.equals(gold_label))
System.out.println(pred_label + " : " + testset.getInstance(i).getSource());
else
System.err.println(
gold_label + "->" + pred_label + " : " + testset.getInstance(i).getSource());
}
/** 分类器使用 */
String str = "韦德：不拿冠军就是失败 詹皇：没拿也不意味失败";
System.out.println("============\n分类：" + str);
Pipe p = cl.getPipe();
Instance inst = new Instance(str);
try {
// 特征转换
p.addThruPipe(inst);
} catch (Exception e) {
e.printStackTrace();
}
String res = cl.getStringLabel(inst);
System.out.println("类别：" + res);
// 清除模型文件
(new File(modelFile)).deleteOnExit();
// System.exit(0);
}
