Bleeding edge lme4 (or lme4a) plus DF estimation

Dr Bates,

Thank you for your reply.

I discovered a bug on your lme4Eigen's refit function. This is on version 0.9996875-9 (Description revision 169). I hope I got this right. If the original data matrix has some missing data in it, somehow the X and Z matrices (and y column) are correctly trimmed (i.e., the rows with missing data are removed). However, if I fit it with another y column, it reports error due to length mismatch. The error is as follows:
Error: length(newresp <- as.numeric(as.vector(newresp))) == length(rr$y) is not TRUE

Should I try the latest version and see if this bug has been fixed?

Also, will update method speed up computation if I changed the X (or Z) matrix a little bit by swapping or adding up to three columns (from about 40+ columns)?

Thank you,
Roby

Yes, check out the refit function.  I just saw that the documentation
suffers from cut-and-paste errors but the general idea is to give a
fitted model a new response and run only the optimization step.