Java WEKA API - StratifiedRemoveFolds

Question

我有大约 100 个 csv 格式的数据集，我想应用 Weka 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);当我运行它时，我收到以下错误消息：stratifyDatasetsWithWekaApi SEVERE: nullweka.core.UnassignedClassException: weka filters.supervised.instance.StratifiedRemoveFolds: Class attribute not set!我也尝试过以下方法：CSVLoader loader = new CSVLoader();loader.setSource(new File(datasetToBeProcessed.toString()));Instances data = loader.getDataSet();String[] options = new String[4]; // initialize optionsoptions[0] = "-S 0"; // seed numberoptions[1] = "-V"; // invert selectionoptions[2] = "-N 8"; // total number of foldsoptions[3] = "-F 1";  // current foldstrRmvFolds.setOptions(options);strRmvFolds.setInputFormat(data);data = StratifiedRemoveFolds.useFilter(data, strRmvFolds);错误信息是：stratifyDatasetsWithWekaApiSEVERE: nulljava.lang.Exception: Illegal options: -S 0 -N 8 -F 1 我究竟做错了什么？

Answer 1

您需要为加载的实例设置类索引。类索引通常是最后一个索引。您可以将其设置为：

Instances data = loader.getDataSet();

data.setClassIndex(data.numAttributes() - 1);