[R] , how to express bar(zeta) in main title in boxplot

[Peter Ehlers]

On 2010-07-22 15:21, David Winsemius wrote:
>
> On Jul 22, 2010, at 5:01 PM, Peter Ehlers wrote:
>
>> On 2010-07-22 14:40, David Winsemius wrote:
>>>
>>> On Jul 22, 2010, at 4:24 PM, Peter Ehlers wrote:
>>>
>>>> On 2010-07-22 11:44, Marcus Liu wrote:
>>>>> Hi everyone, I am plotting a boxplot with main title as main =
>>>>> bquote(paste(.(ts.ind[s]), ": ", bar(zeta), " Boxplot from 2001 to
>>>>> 2009", sep = "")) but it doesn't work. The program said they cannot
>>>>> find the function "bar". Does anyone know how to do it correctly?
>>>>> Thanks.
>>>>>
>>>>
>>>> A reproducible example with the exact error message would
>>>> be good. Anyway, it seems pretty clear what you want and
>>>> one solution is to _not_ use 'main='. For base graphics,
>>>> I usually prefer to add titles with the title() function
>>>> which will work here.
>>>>
>>>> a <- pi
>>>> boxplot(rnorm(200))
>>>> title(bquote(paste(.(a), ": ", bar(zeta),
>>>> " Boxplot from 2001 to 2009", sep = "")))
>>>>
>>>> It seems that setting main=<...> where <...> contains
>>>> bquote() works with plot(), but not with boxplot().
>>>
>>> The help page for boxplot does not document a "main" argument, nor is it
>>> in the argument list for boxplot.default or its bxp function. The
>>> documentation for the "..." argument does not suggest, to me anyway,
>>> that main would passed on to other graphical functions.
>>>
>>
>> Well, that's not quite so. From ?bxp:
>>
>> ".... and main, cex.main, col.main, sub, cex.sub, col.sub, xlab,
>> ylab, cex.lab, and col.lab are passed to title"
>
> I stand (or sit) corrected.
>
>>
>> # To wit:
>> y <- rnorm(200)
>> g <- gl(2,100)
>> boxplot(y ~ g, main="My title")
>>
>> # But I wasn't right, either:
>> a <- pi
>> boxplot(y ~ g, main=paste("hello", bquote(.(a)), "goodbye"))
>> boxplot(y ~ g, main=expression("hello"~~bar(zeta)~~"goodbye"))
>>
>> I do usually prefer to use main="" and then supply the title
>> separately. But I'll wager that either Gabor or Uwe or ...
>> will make main= work for the OP.
>
> Both are working on my machine.
>

I thought I was only getting this to work with either the
paste(..., bquote(), ...) form *or* the
expression(... bar(zeta) ...) form,
but I see that the paste() in the OP's request was not
necessary and so his question is also answered by:

   boxplot(y ~ g, main =
         bquote(.(a) ~~ "hello" ~~ bar(zeta) ~~ "goodbye"))

which really should have been obvious to me. Duh...

Curiously (?), plot() will accept this:

   plot(0, main = bquote(paste(.(a), "hello", bar(zeta), "goodbye")))

which had led me astray.

Now, why doesn't this work with lattice's bwplot?

   -Peter Ehlers