On Wed, Dec 7, 2016 at 7:04 AM, Jeff Newmiller <jdnew...@dcn.davis.ca.us> wrote:
> Your error is in thinking that environment variables are the same thing as
> options. While environment variables might be used to set initial values of
> certain options, options are completely separate from environment variables.
> If you want to change the option on the fly, then change the option.
i.e. ?options
-- Bert
> --
> Sent from my phone. Please excuse my brevity.
>
> On December 7, 2016 6:26:55 AM PST, Marc Girondot via R-help
> <r-help@r-project.org> wrote:
>>Hi,
>>
>> From the documentation of ?options
>>
>>Options set in package parallel
>>These will be set when package parallel (or its namespace) is loaded if
>>
>>not already set.
>>
>>mc.cores:
>>a integer giving the maximum allowed number of additional R processes
>>allowed to be run in parallel to the current R process. Defaults to the
>>
>>setting of the environment variable MC_CORES if set. Most applications
>>which use this assume a limit of 2 if it is unset.
>>
>>Then I try:
>> > getOption("mc.cores")
>>NULL
>>
>>I suspect that my environment variable MC_CORES is not set. I test and
>>that's right:
>> > Sys.getenv("MC_CORES")
>>[1] ""
>>
>>Then I do:
>> > Sys.setenv(MC_CORES=4)
>> > Sys.getenv("MC_CORES")
>>[1] "4"
>>
>>But when I try again getOption("mc.cores"); it does not change:
>> > getOption("mc.cores")
>>NULL
>>
>>Probably I do something wrong but I don't see what !
>>
>>Thanks
>>
>>Marc
>>
>>______________________________________________
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>>PLEASE do read the posting guide
>>http://www.R-project.org/posting-guide.html
>>and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> 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.
______________________________________________
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
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