How does List::Util 'shuffle' actually work?
问题 I am currently working on building a classifier using c5.0. I have a dataset of 8000 entries and each entry has its own i.d number (1-8000). When testing the performance of the classifier I had to make 5sets of 10:90 (training data: test data) splits. Of course any training cases cannot appear again in the test cases, and duplicates cannot occur in either set. To solve the problem of picking examples at random for the training data, and making sure the same cannot be picked for the test data