[R] Plotmath bug or my misunderstanding?

[David Winsemius]

On May 12, 2012, at 6:27 PM, Peter Ehlers wrote:

> Hi Bert,
>
> I think the 'cex=' argument applies to the outermost 'atop()'.
> It then applies that size specification to each of the two
> components of the atop(a,b). If one of the components is itself
> another atop(a,b), then the individual parts are sized downward
> to produce the required cex for the unit.
>
> As for the 'cex=1:2' specification, only the first value is used.

Isn't there also a 0.67 factor being applied to whatever was the  
"outside" size prior to being used for the atop arguments? So the  
inner atop arguments get that applied twice if I understand correctly.

text(1,1,labels=expression(atop(
                atop("top level one", "top level two"),
                "another level")
      ) )


I did notice that the cr-linefeed (perhaps unintentionally being  
inserted by a mail client) seemed to be "working" at least on my Mac :

plot(1,1)
text(1,1,labels=expression("another
level")
      )

Whereas it is well known that "\n" will appear as two characters, \n,  
and not be interpreted as a special.
-- 
David
>
> Cheers,
> Peter Ehlers
>
> On 2012-05-12 14:05, Bert Gunter wrote:
>> This is a followup to a recent post on using atop() to obtain
>> multiline expressions.
>>
>> My reading of the plotmath docs makes it clear that issuing (in base
>> graphics) the specification
>>
>> par(cex = 2)
>>
>> doubles symbols and regular text in subsequent plotmath expressions.
>> However, it is unclear to me what specifying cex _within_ the
>> annotation function using plotmath should do, and the following seems
>> to want to have it both ways: ignore/obey )or maybe recycle?)
>>
>> plot(1,type="n", xaxt='n', yaxt='n', ann=FALSE)
>>  text(1,1,labels=expression(atop(sigma,"some text")),cex = 2)
>> ## obeys the cex specification in symbols and text
>>
>> HOWEVER
>>
>> plot(1,type="n", xaxt='n', yaxt='n', ann=FALSE)
>>  text(1,1,labels=expression(atop(atop(sigma,"some text"),"another
>> level")),cex = 2)
>> ## ???
>>
>> For even more fun, try:
>>
>> plot(1,type="n", xaxt='n', yaxt='n', ann=FALSE)
>>  text(1,1,labels=expression(atop(atop(sigma,"some text"),"another
>> level")),cex = 1:2)
>> ##????
>>
>> So I confess to being flummoxed. Enlightenment would be much  
>> appreciated.
>>
>> Cheers,
>> Bert
>>
>>
>>
>>
>
> ______________________________________________
> R-help at r-project.org mailing list
> 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.

David Winsemius, MD
West Hartford, CT