k层交叉检验(k-flod cross-validation)
当然这个称呼也是随着k值的变化而变化的,如果5-flod cross-validation就叫做5层交叉检验。
就是说把原始数据分成k份,选一份做为测试数据,剩下的k-1份做为训练数据。
下面附英文解释(To foreigner friends)
InK-foldcross-validation, the original sample is randomly partitioned intoKsubsamples.Of theKsubsamples, a single subsample is retained as the validation data for testing the model, and the remaining (K−1)subsamples are used as training data. The cross-validation process is thenrepeatedKtimes (thefolds), with each of theKsubsamplesused exactly once as the validation data. TheKresults fromthe folds then can be averaged (or otherwise combined) to produce a singleestimation. The advantage of this method over repeated random sub-sampling isthat all observations are used for both training and validation, and eachobservation is used for validation exactly once. 10-fold cross-validation iscommonly used.