[R-pkg-devel] Effieciency drop in do.call?

[Paul Buerkner]

Thanks! You are likely right that this was the problem. Actually, I was
using a pattern of the form

args <- nlist(a, b, c, ...)
do.call(fun, args)

where nlist() uses NSE to set names for unnamed arguments.

As I was passing big model objects and data through multiple layers of
do.call(), it is not unlikely
that some ended up being deparsed in the wrong way when evaluated in
do.call().

Paul



Am Mo., 19. Nov. 2018 um 22:33 Uhr schrieb peter dalgaard <pdalgd using gmail.com
>:

> If it was just about args evaluation, then the slowness would be in the
> list() call, no?
> An accidental deparse of a large structure could well be the culprit.
>
> -pd
>
>
> > On 19 Nov 2018, at 18:53 , Gabor Grothendieck <ggrothendieck using gmail.com>
> wrote:
> >
> > The do.call version evaluates all arguments while the normal version
> > may not depending on the function.  There could also be a difference
> > if the function uses non-standard evaluation since in that case the
> > two could be passing different different argument values.
> >
> > For an example of the second case,
> >
> >  f <- function(x) deparse(substitute(x))
> >
> >  f(pi)
> >  ## [1] "pi"
> >
> >  do.call("f", list(pi))
> >  ## [1] "3.14159265358979"
> >
> > On Mon, Nov 19, 2018 at 11:50 AM Paul Buerkner <paul.buerkner using gmail.com>
> wrote:
> >>
> >> Hi all,
> >>
> >> today, I stumbled upon a puzzling (to me) problem apparently related to
> >> do.call() that resulted
> >> in an efficiency drop of multiple orders of magnitudes compared to just
> >> calling the function directly (multiple minutes as compared to one
> second).
> >>
> >> That is
> >>
> >> fun(a = a, b = b, c = c, ...)
> >>
> >> took one second, while
> >>
> >> args <- list(a = a, b = b, c = c, ...)
> >> do.call(fun, args)
> >>
> >> took multiple minutes.
> >>
> >> In my package (brms), I use do.call in various places but only in one it
> >> resulted in this
> >> efficiency drop.
> >>
> >> Before I try to make a reproducible example, I wanted to ask if there
> are
> >> any known issues
> >> with do.call that may explain this?
> >>
> >> Paul
> >>
> >>        [[alternative HTML version deleted]]
> >>
> >> ______________________________________________
> >> R-package-devel using r-project.org mailing list
> >> https://stat.ethz.ch/mailman/listinfo/r-package-devel
> >
> >
> >
> > --
> > Statistics & Software Consulting
> > GKX Group, GKX Associates Inc.
> > tel: 1-877-GKX-GROUP
> > email: ggrothendieck at gmail.com
> >
> > ______________________________________________
> > R-package-devel using r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-package-devel
>
> --
> Peter Dalgaard, Professor,
> Center for Statistics, Copenhagen Business School
> Solbjerg Plads 3, 2000 Frederiksberg, Denmark
> Phone: (+45)38153501
> Office: A 4.23
> Email: pd.mes using cbs.dk  Priv: PDalgd using gmail.com
>
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