Column-wise k-fold CV by held-out samples: for each fold, the model is fit on the training columns and evaluated on the held-out columns by solving for new-sample coefficients via a weighted refit with \(X\) fixed.
Arguments
- Y
Real-valued \(Q_{\mathrm{obs}} \times N\) response matrix (signed entries allowed).
- A
Real-valued \(D \times N\) covariate matrix (signed).
- rank
Integer \(Q\).
- ...
Passed to
nmfkc.signed; also acceptsnfolds(default 5;divalias),seed(default 123),shuffle(defaultTRUE).
Value
A list with objfunc (mean squared prediction error),
sigma (RMSE), objfunc.block (per-fold MSE vector),
block (integer fold assignment of length \(N\)). Field
names match nmfkc.cv.
References
Ding, C. H. Q., Li, T., & Jordan, M. I. (2010). Convex and semi-nonnegative matrix factorizations. IEEE Transactions on Pattern Analysis and Machine Intelligence, 32(1), 45–55.