search for: mer_update_y

...39;ve tried to use internal functions from the Matrix package (as suggested ealier on the list by Doug Bates). So I did: fm2 <- lmer(resistance ~ ET + position + (1|Grp), Semiconductor,method='ML') simdata<-simulate(fm2,nsim=1) ynew <- simdata[,1] mer <- fm2 .Call("mer_update_y", mer, ynew, PACKAGE = "Matrix") mer1u <- LMEoptimize(mer, lmerControl(mer)) What puzzles me is that this call alters my original model fm2 as some kind of side effect. In fact, after the call fm2 is the same as mer1u. Is this side effect intentional and is it possible to avoid...