[R] lattice: how to "center" a subtitle?

[David Winsemius]

On Apr 4, 2011, at 1:27 PM, Marius Hofert wrote:

> Dear David,
>
> do you know how to get plotmath-like symbols in both rows?
> I tried s.th. like:
>
> lab <- expression(paste(alpha==1, ", ", beta==2, sep=""))
> xlab <- substitute(expression( atop(lab==lab., bold(foo)) ),  
> list(lab.=lab))
> xyplot(0 ~ 0, xlab = xlab)

I _did_ have plotmath functions in both rows: But here is your solution:

xyplot(0 ~ 0,  xlab =
     expression( atop(paste(alpha==1, "   ", beta==2), bold(bla) )) )
       )

Note that `paste` in plotmath is different than `paste` in regular R.  
It has no `sep` argument. I did try both substitute and bquote on you  
externally expression,  but lattice seems to be doing some non- 
standard evaluation and I never got it to "work". Using what I thought  
_should_ work, does work with `plot`:

 > x=1;y=2
 > plot(0 ~ 0, xlab = bquote( atop(alpha==.(x)*","~beta==.(y),  
bold(foo) ) )
+ )

But the same expression throws an error with xyplot:
 > x=1;y=2
 > xyplot(0 ~ 0, xlab = bquote( atop(alpha==.(x)*","~beta==.(y),  
bold(foo) ) )
+ )
Error in trellis.skeleton(formula = 0 ~ 0, cond = list(1L), aspect =  
"fill",  :
   could not find function "atop"

-- 
David.


>
> Cheers,
>
> Marius
>
> On 2011-04-04, at 18:59 , David Winsemius wrote:
>
>>
>> On Apr 4, 2011, at 12:45 PM, Marius Hofert wrote:
>>
>>> Dear David,
>>>
>>> I intended to use another x-label. But your suggestion brings me  
>>> to the idea of just using a two-line xlab, so s.th. like
>>> print(xyplot(0 ~ 0, xlab.top = "This title is now 'centered' for  
>>> the human's eye", xlab = "but subtitles are _now_ centered\nbla",  
>>> scales = list(alternating = c(1,1), tck = c(1,0))))
>>
>> And if you wanted different fontface (underline, italic or bold)  
>> then you could use plotmath expressions:
>>
>> xyplot(0 ~ 0, xlab.top = "This title is now 'centered' for the  
>> human's eye", xlab =  
>> expression( atop(but~subtitles2~are~underline(now)~centered,  
>> bold(bla) )), scales = list(alternating = c(1,1), tck = c(1,0)))
>>
>> -- 
>> David.
>>
>>>
>>> Thanks!
>>>
>>> Cheers,
>>>
>>> Marius
>>>
>>> On 2011-04-04, at 16:47 , David Winsemius wrote:
>>>
>>>>
>>>> On Apr 4, 2011, at 7:39 AM, Marius Hofert wrote:
>>>>
>>>>> Dear expeRts,
>>>>>
>>>>> I recently asked for a real "centered" title (see, e.g., http://tolstoy.newcastle.edu.au/R/e13/help/11/01/0135.html) 
>>>>> .
>>>>> A nice solution (from Deepayan Sarkar) is to use "xlab.top"  
>>>>> instead of "main":
>>>>>
>>>>> library(lattice)
>>>>> trellis.device("pdf")
>>>>> print(xyplot(0 ~ 0, xlab.top = "This title is now 'centered' for  
>>>>> the human's eye", sub = "but subtitles are not centered", scales  
>>>>> = list(alternating = c(1,1), tck = c(1,0))))
>>>>> dev.off()
>>>>
>>>> library(lattice)
>>>> trellis.device("pdf")
>>>> print(xyplot(0 ~ 0, xlab.top = "This title is now 'centered' for  
>>>> the human's eye", xlab = "but subtitles are _now_ centered",  
>>>> scales = list(alternating = c(1,1), tck = c(1,0))))
>>>> dev.off()
>>>>
>>>>
>>>> (I realize that those are not really subtitles by a 'lab', but  
>>>> that appears acceptable in your current test case.)
>>>>
>>>>>
>>>>> My question is whether there is something similar for  
>>>>> *sub*titles [so something like "xlab.bottom"]? As you can see  
>>>>> from the plot, the subtitle does not seem to be "centered" for  
>>>>> the human's eye. I would like to center it according to the x- 
>>>>> axis label.
>>>>>
>>>>
>>>>
>>>> David Winsemius, MD
>>>> West Hartford, CT
>>>>
>>>
>>
>> David Winsemius, MD
>> West Hartford, CT
>>
>

David Winsemius, MD
West Hartford, CT