This is nothing specific to parallel::clusterApply() per se. It is the default behavior of R where it allows for partial argument names. I don't think there's much that can be done here except always using fully named arguments to the "apply" function itself as you show.
You can "alert" yourself when there's a mistake by using: options(warnPartialMatchArgs = TRUE) e.g. > clusterApply(clu, x = 1:2, fun = fun, c = 1) ## Error Warning in clusterApply(clu, x = 1:2, fun = fun, c = 1) : partial argument match of 'c' to 'cl' Error in checkCluster(cl) : not a valid cluster It's still only a warning, but an informative one. /Henrik On Wed, Mar 14, 2018 at 8:50 AM, Florian Schwendinger <florian_schwendin...@gmx.at> wrote: > Hi! > > I recognized that the argument matching of clusterApply (and therefore > parLapply) goes wrong when one of the arguments of the function is called > "c". In this case, the argument "c" is used as cluster and the functions give > the following error message "Error in checkCluster(cl) : not a valid cluster". > > Of course, "c" is for many reasons an unfortunate argument name and this can > be easily fixed by the user side. > > See below for a small example. > > library(parallel) > > clu <- makeCluster(2, "PSOCK") > > fun <- function(x0, x1) (x0 + x1) > clusterApply(clu, x = 1:2, fun = fun, x1 = 1) ## OK > parLapply(cl = clu, X = 1:2, fun = fun, x1 = 1) #OK > > > fun <- function(b, c) (b + c) > clusterApply(clu, x = 1:2, fun = fun, c = 1) ## Error > clusterApply(cl = clu, x = 1:2, fun = fun, c = 1) ## OK > parLapply(cl = clu, X = 1:2, fun = fun, c = 1) ## Error > > stopCluster(clu) > > > I used "R version 3.4.3 Patched (2018-01-07 r74099". > > > Best regards, > Florian > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
