Java的API WEKA - StratifiedRemoveFolds

Question

我在csv格式〜100点的数据集，我想申请Weka的过滤器StratifiedRemoveFolds。 到目前为止我的代码是：

CSVLoader loader = new CSVLoader();
loader.setSource(new File(datasetToBeProcessed.toString()));
Instances data = loader.getDataSet();

StratifiedRemoveFolds strRmvFolds = new StratifiedRemoveFolds();
strRmvFolds.setFold(fold);
strRmvFolds.setNumFolds(DatasetPreprocessing.numberOfFolds);
strRmvFolds.setSeed(0);
strRmvFolds.setInvertSelection(false);
strRmvFolds.setInputFormat(data);
data = StratifiedRemoveFolds.useFilter(data, strRmvFolds);

当我运行此我得到以下错误信息：

stratifyDatasetsWithWekaApi 
SEVERE: null
weka.core.UnassignedClassException: 
weka filters.supervised.instance.StratifiedRemoveFolds: 
Class attribute not set!

我试过下面还有：

CSVLoader loader = new CSVLoader();
loader.setSource(new File(datasetToBeProcessed.toString()));
Instances data = loader.getDataSet();

String[] options = new String[4]; // initialize options
options[0] = "-S 0"; // seed number
options[1] = "-V"; // invert selection
options[2] = "-N 8"; // total number of folds
options[3] = "-F 1";  // current fold

strRmvFolds.setOptions(options);
strRmvFolds.setInputFormat(data);
data = StratifiedRemoveFolds.useFilter(data, strRmvFolds);

错误信息：

stratifyDatasetsWithWekaApi
SEVERE: null
java.lang.Exception: Illegal options: -S 0 -N 8 -F 1 

我究竟做错了什么？

谢谢，PAUL

http://weka.sourceforge.net/doc.dev/weka/filters/supervised/instance/StratifiedRemoveFolds.html

Answer 1

您需要设置加载的情况下，该类指标。类指数通常是最后一个索引。您可以设置它，如：

Instances data = loader.getDataSet();
data.setClassIndex(data.numAttributes() - 1);