[Rd] legend() in a multiple figure environment

[Duncan Murdoch]

On 1/8/2009 9:29 AM, Simone Giannerini wrote:
> Now I got how to reproduce it, it has nothing to do with multiple
> figure environment but rather with figure resizing. Here it is:
> 
>  curve(dnorm,col=4,from=-4,to=4);
>  legend(-4,0.3,legend="curve",lty=1,col=4)
> 
> # Now expand the figure to full screen
> 
> legend(-4,0.2,legend="curve",lty=1,col=4)

I think the only advice here is "don't do that".  The problem is that 
the box is sized appropriately to surround the text when it is first 
drawn, then you scale everything up except the text, so the box becomes 
too big.  The new box is appropriate to the text at the new size.

Then you scale everything again when you save to a file, and the boxes 
end up different again.

So the advice is:   draw legends with the plot at its final size if you 
want the sizing to work properly.  R doesn't save the fact that the size 
is supposed to be relative to the text, rather than relative to the plot 
region.

Duncan Murdoch

> Simone
> 
> On Thu, Jan 8, 2009 at 2:39 PM, Martin Maechler
> <maechler at stat.math.ethz.ch> wrote:
>>
>> >>>>> "SG" == Simone Giannerini <sgiannerini at gmail.com>
>> >>>>>     on Thu, 8 Jan 2009 14:08:17 +0100 writes:
>>
>>    SG> Dear Mathieu, On Thu, Jan 8, 2009 at 12:14 PM, Mathieu
>>    SG> Ribatet <mathieu.ribatet at epfl.ch> wrote:
>>    >> Dear Simone,
>>    >>
>>    >> Did mean that the legend (text and/or box) overlap with
>>    >> the Normal density?
>>
>>    SG> no, I mean that the two legend() commands, which are
>>    SG> identical in all but the y-coordinates, produce
>>    SG> different results, namely boxes with different widths.
>>
>> I don't see that behavior at all, rather the two boxes have
>> identical dimensions for me.
>>
>> What does  dev.cur() say?  if anything with "X11..." (as you are
>> on Linux),  what does
>>
>>  str(X11.options())
>>
>> give?
>>
>>
>>    SG> Ciao
>>
>>    SG> Simone
>>
>>    >> If so then I think there's no problem as the legend is
>>    >> placed where you told R to do. And R won't check (for
>>    >> you) if it will overlap or not with pre-existing
>>    >> graphical elements.
>>    >>
>>    >> On my computer, I got the expected results - if I
>>    >> understood correctly your issue though. For information:
>>    >>
>>    >> R version 2.8.1 (2008-12-22) Linux mathieu-laptop
>>    >> 2.6.27-11-generic #1 SMP Fri Dec 19 16:29:52 UTC 2008
>>    >> i686 GNU/Linux (Ubuntu Intrepid)
>>    >>
>>    >> Cheers, Mathieu
>>    >>
>>    >> Simone Giannerini a écrit :
>>    >>>
>>    >>> Dear all,
>>    >>>
>>    >>> there seems to be a problem with displayed legends when
>>    >>> a multiple figure environment is used, see the following
>>    >>> example:
>>    >>>
>>    >>> par(mfrow=c(1,2)) curve(dnorm,col=4,from=-4,to=4);
>>    >>> legend(-4,0.3,legend="curve",lty=1,col=4)
>>    >>> legend(-4,0.2,legend="curve",lty=1,col=4)
>>    >>>
>>    >>>
>>    >>> On my machines the first time the command legend() is
>>    >>> issued the legend box stretches over the
>>    >>> curve. Subsequent calls to legend seems to produce a
>>    >>> correct box instead.
>>    >>>
>>    >>> openSuse 11.0
>>    >>>
>>    >>> platform x86_64-unknown-linux-gnu arch x86_64 os
>>    >>> linux-gnu system x86_64, linux-gnu status Patched major
>>    >>> 2 minor 8.1 year 2009 month 01 day 07 svn rev 47501
>>    >>> language R version.string R version 2.8.1 Patched
>>    >>> (2009-01-07 r47501)
>>    >>>
>>    >>> I see this on the same version of R on Windows VISTA 32
>>    >>> bit as well; I do not see this behaviour on a machine
>>    >>> with R 2.8.0.
>>    >>>
>>    >>> Thank you,
>>    >>>
>>    >>> Simone
>>    >>> --
>>    >>> ______________________________________________________
>>    >>>
>>    >>> Simone Giannerini Dipartimento di Scienze Statistiche
>>    >>> "Paolo Fortunati" Universita' di Bologna Via delle belle
>>    >>> arti 41 - 40126 Bologna, ITALY Tel: +39 051 2098262 Fax:
>>    >>> +39 051 232153 http://www2.stat.unibo.it/giannerini/
>>    >>>
>>    >>> ______________________________________________
>>    >>> R-devel at r-project.org mailing list
>>    >>> https://stat.ethz.ch/mailman/listinfo/r-devel
>>    >>>
>>    >>
>> > --
>> > Institute of Mathematics Ecole Polytechnique Fédérale de
>>    >> Lausanne STAT-IMA-FSB-EPFL, Station 8 CH-1015 Lausanne
>>    >> Switzerland http://stat.epfl.ch/ Tel: + 41 (0)21 693 7907
>>    >>
>>    >>
>>    >>
>>
>>
>>
>> --
>> ______________________________________________________
>>
>>    SG> Simone Giannerini Dipartimento di Scienze Statistiche
>>    SG> "Paolo Fortunati" Universita' di Bologna Via delle belle
>>    SG> arti 41 - 40126 Bologna, ITALY Tel: +39 051 2098262 Fax:
>>    SG> +39 051 232153 http://www2.stat.unibo.it/giannerini/
>>
>>    SG> ______________________________________________
>>    SG> R-devel at r-project.org mailing list
>>    SG> https://stat.ethz.ch/mailman/listinfo/r-devel
> 
> 
> 
> --
> ______________________________________________________
> 
> Simone Giannerini
> Dipartimento di Scienze Statistiche "Paolo Fortunati"
> Universita' di Bologna
> Via delle belle arti 41 - 40126  Bologna,  ITALY
> Tel: +39 051 2098262  Fax: +39 051 232153
> http://www2.stat.unibo.it/giannerini/
> 
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