hold.setClassIndex(hold.numAttributes() - 1);
// att sel ranking
Random rndd = new Random(422);
AttributeSelection attribSel = new AttributeSelection();
att_ev_TTestAttributeEval pval = new att_ev_TTestAttributeEval();
Ranker rnkr = new Ranker();
// rnkr.setThreshold(p_val_threshold);
// roc.buildEvaluator(learn);
attribSel.setEvaluator(pval);
attribSel.setSearch(rnkr);
attribSel.setInputFormat(learn);
Instances learnPostSel = attribSel.useFilter(learn, attribSel);
Instances holdPostSel = attribSel.useFilter(hold, attribSel);
wrep.TTEST_univariate_p_value_raw = new double[learnPostSel.numAttributes() - 1];
wrep.TTEST_univariate_p_value_log = new double[learnPostSel.numAttributes() - 1];
wrep.TTEST_univariate_fold_change_log = new double[learnPostSel.numAttributes() - 1];
wrep.TTEST_univariate_fold_change_raw = new double[learnPostSel.numAttributes() - 1];