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-rw-r--r--R/multistart.R34
1 files changed, 24 insertions, 10 deletions
diff --git a/R/multistart.R b/R/multistart.R
index beb8194b..cc55feae 100644
--- a/R/multistart.R
+++ b/R/multistart.R
@@ -7,9 +7,6 @@
#' inspired by the article on practical identifiabiliy in the frame of nonlinear
#' mixed-effects models by Duchesne et al (2021).
#'
-#' Currently, parallel execution of the fits is only supported using
-#' [parallel::mclapply], i.e. not available on Windows.
-#'
#' In case the online version of this help page contains error messages
#' in the example code and no plots, this is due to the multistart method
#' not working when called by pkgdown. Please refer to the
@@ -19,7 +16,9 @@
#' @param object The fit object to work with
#' @param n How many different combinations of starting parameters should be
#' used?
-#' @param cores How many fits should be run in parallel?
+#' @param cores How many fits should be run in parallel (only on posix platforms)?
+#' @param cluster A cluster as returned by [parallel::makeCluster] to be used
+#' for parallel execution.
#' @param \dots Passed to the update function.
#' @param x The multistart object to print
#' @return A list of [saem.mmkin] objects, with class attributes
@@ -50,17 +49,26 @@
#' parhist(f_saem_full_multi, lpos = "bottomright")
#'
#' f_saem_reduced <- update(f_saem_full, covariance.model = diag(c(1, 1, 0, 1)))
-#' f_saem_reduced_multi <- multistart(f_saem_reduced, n = 16, cores = 16)
+#' # On Windows, we need to create a cluster first. When working with
+#' # such a cluster, we need to export the mmkin object to the cluster
+#' # nodes, as it is referred to when updating the saem object on the nodes.
+#' library(parallel)
+#' cl <- makePSOCKcluster(12)
+#' clusterExport(cl, "f_mmkin")
+#' f_saem_reduced_multi <- multistart(f_saem_reduced, n = 16, cluster = cl)
#' parhist(f_saem_reduced_multi, lpos = "bottomright")
#' }
-multistart <- function(object, n = 50, cores = 1, ...)
+multistart <- function(object, n = 50,
+ cores = if (Sys.info()["sysname"] == "Windows") 1 else parallel::detectCores(),
+ cluster = NULL, ...)
{
UseMethod("multistart", object)
}
#' @rdname multistart
#' @export
-multistart.saem.mmkin <- function(object, n = 50, cores = 1, ...) {
+multistart.saem.mmkin <- function(object, n = 50, cores = 1,
+ cluster = NULL, ...) {
if (n <= 1) stop("Please specify an n of at least 2")
mmkin_parms <- parms(object$mmkin, errparms = FALSE,
@@ -69,9 +77,15 @@ multistart.saem.mmkin <- function(object, n = 50, cores = 1, ...) {
mmkin_parms, 1,
function(x) stats::runif(n, min(x), max(x)))
- res <- parallel::mclapply(1:n, function(x) {
- update(object, degparms_start = start_parms[x, ], ...)
- }, mc.cores = cores)
+ if (is.null(cluster)) {
+ res <- parallel::mclapply(1:n, function (x) {
+ update(object, degparms_start = start_parms[x, ], ...)
+ }, mc.cores = cores)
+ } else {
+ res <- parallel::parLapply(cluster, 1:n, function(x) {
+ update(object, degparms_start = start_parms[x, ], ...)
+ })
+ }
attr(res, "orig") <- object
attr(res, "start_parms") <- start_parms
class(res) <- c("multistart.saem.mmkin", "multistart")

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