R/findMultiBUGS.R

In MultiBUGS/R2MultiBUGS: Running MultiBUGS from R

findMultiBUGS <- function(){
  dir <- Sys.getenv("MultiBUGS_PATH")
  if (nchar(dir)){
    return(dir)
  }

  dir <- getOption("R2MultiBUGS.pgm")
  if (!is.null(dir)){
    return(dir)
  }

  if (.Platform$OS.type != "windows"){
    return(Sys.which("MultiBUGS"))
  }

  deps <- utils::packageDescription("R2MultiBUGS", fields = "SystemRequirements")
  version.req <- gsub(".*MultiBUGS ?\\(>= ?(.+)\\).*", "\\1", deps)
  ob.reg <- try(utils::readRegistry("Software\\MultiBUGS",
                                    "HLM",
                                    view = "32-bit"),
                silent = TRUE)
  if (inherits(ob.reg, "try-error")){
    return(NA)
  }

  rnames <- names(ob.reg)
  ver <- gsub("MultiBUGS ", "", rnames)
  version.inst <- gsub("(.+)e$", "\\1", ver)

  if (length(version.inst > 1)){
    id <- which(apply(outer(version.inst,
                            version.inst,
                            Vectorize(compareVersion, c("a", "b"))),
                      1,
                      function(x) all(x >= 0)))
    version.inst <- version.inst[id]
    rnames <- rnames[id]
  }

  if (compareVersion(max(version.inst), version.req) < 0){
    warning("Found MultiBUGS version ",
            version.inst,
            ".\n Requires ",
            version.req,
            " or greater.")
  }

  utils::readRegistry(paste("Software",
                            "MultiBUGS",
                            rnames,
                            sep = "\\"),
                      "HLM",
                      view = "32-bit")[["InstallPath"]]
}