[R] how to stop without error message?

[John Fox]

Dear Mark,

I see what you mean. Clearly the problem is with try(), since if you
eliminate that, the message disappears.

On the other hand, if you use try( f.inner(), silent=TRUE), the message is
also suppressed.

Does that help?

John


> -----Original Message-----
> From: Mark.Bravington at csiro.au [mailto:Mark.Bravington at csiro.au]
> Sent: November-10-08 8:22 PM
> To: jfox at MCMASTER.CA; R-help at r-project.org
> Subject: RE: [R] how to stop without error message?
> 
> Hi John
> 
> Using 'on.exit' to reset the "show.error.messages" option should work, but
it
> doesn't quite... and I'm not sure why.
> 
> It breaks down with, for want of a better phrase, "nested" calls to stop,
> inside 'try' statements. For some reason, the inner 'stop' calls *do* lead
to
> messages, although the outermost one is suppressed.
> 
> test> f.inner <- function() {
> +   opt.inner <- options( show.error.messages=FALSE)
> +   on.exit( options( opt.inner))
> +   stop( 'leaving f.inner')
> + }
> test>
> test> f.outer <- function() {
> +   try( f.inner())
> +   opt.outer <- options( show.error.messages=FALSE)
> +   on.exit( options( opt.outer))
> +   stop( 'leaving f.outer')
> + }
> test> f.outer()
> Error in f.inner() : leaving f.inner
> test>
> 
> bye
> Mark
> 
> 
> 
> 
> --
> Mark Bravington
> CSIRO Mathematical & Information Sciences
> Marine Laboratory
> Castray Esplanade
> Hobart 7001
> TAS
> 
> ph (+61) 3 6232 5118
> fax (+61) 3 6232 5012
> mob (+61) 438 315 623
> 
> -----Original Message-----
> From: John Fox [mailto:jfox at mcmaster.ca]
> Sent: Tuesday, 11 November 2008 10:35 AM
> To: Bravington, Mark (CMIS, Hobart); R-help at r-project.org
> Subject: RE: [R] how to stop without error message?
> 
> Dear Mark,
> 
> How about something like this?
> 
> > f <- function(x){
> +   if (x < 0){
> +     opt <- options(show.error.messages=FALSE)
> +     on.exit(options(opt))
> +     stop()
> +     }
> +   sqrt(x)
> +   }
> >
> > f(2)
> [1] 1.414214
> > f(-2)
> >
> 
> I hope this helps,
>  John
> 
> ------------------------------
> John Fox, Professor
> Department of Sociology
> McMaster University
> Hamilton, Ontario, Canada
> web: socserv.mcmaster.ca/jfox
> 
> 
> > -----Original Message-----
> > From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
> On
> > Behalf Of Mark.Bravington at csiro.au
> > Sent: November-10-08 5:42 PM
> > To: R-help at r-project.org
> > Cc: Mark.Bravington at csiro.au
> > Subject: [R] how to stop without error message?
> >
> > Dear list
> >
> > Can anyone suggest a simple way to abort execution like stop(...) does,
> but
> > without issuing an "Error: ..." message?
> >
> > I don't want to set 'options( show.error.messages=TRUE)' because I want
> > normal behaviour to resume after this particular stop.
> >
> > (Please reply personally as well as to the list, as I'm not subscribed
to
> R-
> > help)
> >
> > Thanks
> > Mark
> >
> > --
> > Mark Bravington
> > CSIRO Mathematical & Information Sciences
> > Marine Laboratory
> > Castray Esplanade
> > Hobart 7001
> > TAS
> >
> > ph (+61) 3 6232 5118
> > fax (+61) 3 6232 5012
> > mob (+61) 438 315 623
> >
> > ______________________________________________
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> > PLEASE do read the posting guide
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>