I would like to run a logistic regression on some factor variables (main effects and eventually an interaction) that are very sparse. I have a moderately large dataset, ~100k observations with 1500 factor levels for one variable (x1) and 600 for another (X2), creating ~19000 levels for the interaction (X1:X2).
I would like to take advantage of the sparseness in these factors to avoid using GLM. Actually glm is not an option given the size of the design matrix. I have looked through the Matrix package as well as other packages without much help. Is there some option, some modification of glm, some way that it will recognize a sparse matrix and avoid large matrix inversions? -Robin [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.