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> ## this is the simpler version of the code for testing/exercising
> ## https://github.com/lme4/lme4/issues/35
> ## see also ../misc/issues/dynload.R for more complexity
> pkg <- so_name <- "lme4"; doUnload <- FALSE; doTest <- TRUE
> ## pkg <- so_name <- "RcppEigen"; doUnload <- TRUE; doTest <- TRUE
> ## need to deal with the fact that DLL name != package name for lme4.0 ...
> ### pkg <- "lme4.0"; so_name <- "lme4"; doUnload <- TRUE
> instPkgs <- as.data.frame(installed.packages(),stringsAsFactors=FALSE)
> Load <- function() {
+     library(pkg,character.only=TRUE)
+ }
> Unload <- function() {
+     ld <- library.dynam()
+     pnames <- sapply(ld,"[[","name")
+     names(ld) <- pnames
+     lp <- gsub("/libs/.*$","",ld[[so_name]][["path"]])
+     cat("unloading from",lp,"\n")
+     library.dynam.unload(so_name, lp)
+ }
> Detach <- function() {
+     detach(paste0("package:",pkg),character.only=TRUE,unload=TRUE)
+     if (doUnload) Unload()
+ }
> tmpf <- function() {
+     g <- getLoadedDLLs()
+     lnames <- names(g)[is.na(instPkgs[names(g),"Priority"])]
+     cat("loaded DLLs:",lnames,"\n")
+     g <- g[na.omit(match(c(so_name,"nlme"),names(g)))]
+     class(g) <- "DLLInfoList"
+     g
+ }
> test <- function() {
+     if (doTest) {
+         if (pkg %in% c("lme4","lme4.0")) {
+             fm1 <- lmer(Reaction ~ Days + (Days|Subject), sleepstudy,
+                         devFunOnly=TRUE)
+         }
+         if (pkg=="RcppEigen") {
+             data(trees, package="datasets")
+             mm <- cbind(1, log(trees$Girth))   # model matrix
+             y  <- log(trees$Volume)            # response
+             ## bare-bones direct interface
+             flm <- fastLmPure(mm, y)
+         }
+     }
+ }
> if (FALSE) {
+   ## FIXME: disabled test for now
+ for (i in 1:6) {
+     cat("Attempt #",i,"\n",sep="")
+     cat("loading",pkg,"\n")
+     Load()
+     tmpf()
+     test()
+     cat("detaching",pkg,"\n")
+     Detach()
+     cat("loading nlme\n")
+     library("nlme")
+     tmpf()
+     detach("package:nlme",unload=TRUE)
+     cat("detaching nlme\n")
+ }
+ }
> 
> proc.time()
   user  system elapsed 
   0.25    0.18    0.42