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List:       r-help
Subject:    Re: [R] .Call using multiple cores on linux after R 3.3.3
From:       Youyi Fong <youyifong () gmail ! com>
Date:       2019-04-23 17:33:59
Message-ID: CAA4m0Gb+ZHpk82Oyri3sfJMC2EP+Tw=8102jiO9iavc-kJ+7wg () mail ! gmail ! com
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Thanks, Jeff! You are absolutely correct. We have OPENBLAS installed in our
environment that causes this.

One way to "fix" it is:

library(RhpcBLASctl)
blas_get_num_procs()
blas_set_num_threads(1)
stopifnot(blas_get_num_procs()==1)



On Sat, Apr 20, 2019 at 9:06 AM Jeff Newmiller <jdnewmil@dcn.davis.ca.us>
wrote:

> My guess would be that you are running with a non-CRAN distribution of R
> like Anaconda or MRAN that has MKL enabled?
>
> On April 19, 2019 10:25:57 AM PDT, Youyi Fong <youyifong@gmail.com> wrote:
> >Hi, I am wondering why it is the case that in R 3.3.3, calling
> >chngpt:chngptm uses only 1 core, but in later releases, e.g. R 3.4.3,
> >it
> >uses multiple cores on linux. The function chngpt:chngptm has a .Call
> >to
> >invoke a C/C++ function that performs bootstrapping. No explicit
> >parallel
> >computing instructions are used.
> >Thanks,
> >Youyi
> >
> >       [[alternative HTML version deleted]]
> >
> >______________________________________________
> >R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
> >https://stat.ethz.ch/mailman/listinfo/r-help
> >PLEASE do read the posting guide
> >http://www.R-project.org/posting-guide.html
> >and provide commented, minimal, self-contained, reproducible code.
>
> --
> Sent from my phone. Please excuse my brevity.
>

	[[alternative HTML version deleted]]

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