Rating ratio implementation about librec

[guoguibing]

I understand. We have getRatioByUser(ratio) in the RatioDataSplitter for this purpose.

[rburke2233]

I am talking about getRatioByUser(). Because the training / test split is random by item, this method does not guarantee a fixed number of test items for each user and that number might be zero, as in my example with a small test data set. See code fragment here:

			for (int j : items) {
				if (Randoms.uniform() < ratio) {
					testMatrix.set(u, j, 0.0);
				} else {
					trainMatrix.set(u, j, 0.0);
				}
			}

Randoms.uniform() could be less than ratio for all a user's items and then there is no test data for that user.

[guoguibing]

I see. Can you pull a request to fix up this issue? It is always valuable to fix up any issues.

[wangyufengkevin]

This issue has supported in 2.0.0-RC version, the method is getFixedRatioByUser and configuration is data.splitter.ratio=userfixed, please try it.