这是我第二篇关于weka使用情况的帖子(第一篇帖子是here)。我成功地使用TextDirectoryLoader为Weka提供了培训和样本测试数据。很棒。现在我想将它移到生产环境中,所以要从MySQL表中检索要分类的数据。这是我如何做它:Weka来自MySql数据库的培训数据
TextDirectoryLoader loader = new TextDirectoryLoader();
loader.setDirectory(new File("c:/Users/Yehia A.Salam/Desktop/dd/training-data"));
Instances dataRaw = loader.getDataSet();
StringToWordVector filter = new StringToWordVector();
filter.setInputFormat(dataRaw);
Instances dataTraining = Filter.useFilter(dataRaw, filter);
// Create test data instances[this works, but the sample data now needs to come frm the db instead, see below]
//loader.setDirectory(new File("c:/Users/Yehia A.Salam/Desktop/dd/test-data"));
//dataRaw = loader.getDataSet();
//Instances dataTest = Filter.useFilter(dataRaw, filter);
InstanceQuery query = new InstanceQuery();
query.setUsername("myusername");
query.setPassword("mypassword");
String sql = "SELECT d.desc FROM deals d WHERE d.j48 = 1";
query.setQuery(sql);
Instances dataTest = Filter.useFilter(query.retrieveInstances(), filter);
// Classify
J48 model = new J48();
model.buildClassifier(dataTraining);
for (int i = 0; i < dataTest.numInstances(); i++) {
dataTest.instance(i).setClassMissing();
double cls = model.classifyInstance(dataTest.instance(i));
dataTest.instance(i).setClassValue(cls);
System.out.println(cls + " -> " + dataTest.instance(i).classAttribute().value((int) cls));
}
不幸的是这是行不通的,秧鸡意外停止在这条线:
Instances dataTest = Filter.useFilter(query.retrieveInstances(), filter);
所以我想我的问题是如何改造这部分
// Create test data instances[this works, but the sample data now needs to come frm the db instead, see below]
//loader.setDirectory(new File("c:/Users/Yehia A.Salam/Desktop/dd/test-data"));
//dataRaw = loader.getDataSet();
//Instances dataTest = Filter.useFilter(dataRaw, filter);
到SQL基于数据
InstanceQuery query = new InstanceQuery();
query.setUsername("myusername");
query.setPassword("mypassword");
String sql = "SELECT d.desc FROM deals d WHERE d.j48 = 1";
query.setQuery(sql);
Instances dataTest = Filter.useFilter(query.retrieveInstances(), filter);
请注意,数据库连接没有问题,我确实获得了正确数量的实例。
欣赏帮助,非常接近。
weka停止“意外”的堆栈跟踪是什么?你调查了'query.retrieveInstances()'的输出吗? – 2013-03-20 10:46:12
你确定你的SQL:'SELECT d.desc FROM deals d WHERE d.j48 = 1'?我会期望像'SELECT d.desc FROM deal AS d WHERE d.j48 = 1'。 – 2013-03-21 09:39:11
@JanEglinger试图添加AS但没有运气,我检查了query.retrieveInstances()的错误,它的o =(java.lang.ArrayIndexOutOfBoundsException)java.lang.ArrayIndexOutOfBoundsException:1 – 2013-03-25 21:51:31