[R] Adding text outside (lattice barchart) plotting region.

[Deepayan Sarkar]

On Thu, Mar 18, 2010 at 5:26 AM, Peng Cai <pengcaimaillist at gmail.com> wrote:
> Thanks Richard and Jim for your reply!
>
> @All:
>
> Is there a way to do this without altering default x-labels (because in my
> case there could be up to 30-40 x-labels and I may have to repeat the script
> multiple times with different x-lables).
>
> OR, not sure but can it be done by extending plotting region parameters for
> lattice plots (though I'm aware of how to change these).

The most general solution I can think of is to use the legend
functionality (whereby new grid objects can be used as legends). A
simple example is

dotplot(yield ~ year, data = barley,
        legend = list(bottom =
                      list(fun = textGrob,
                           args = list(x = c(0.5, 1, 2), y = 0.5,
label = c("Month:", "March", "April"),
                                       just = "center", default.units
= "native",
                                       vp = viewport(xscale = c(0.4,
2.6), yscale = c(0, 1))))))

More complex layouts will typically need frameGrob (see
lattice::draw.colorkey for an example). Note that the legend doesn't
know what the panel limits are, so you will need to tell it
explicitly.

-Deepayan

>
> Thanks,
> Peng Cai
>
> On Wed, Mar 17, 2010 at 7:27 PM, Jim Lemon <jim at bitwrit.com.au> wrote:
>
>>  On 03/18/2010 09:50 AM, Peng Cai wrote:
>>
>>> Hi All,
>>>
>>> I need some help with adding text at the bottom of the graph (outside of
>>> default outline of graph).
>>>
>>> Say, I need to write "Month:   01     04" below each of the two years in
>>> the
>>> following R code, something like this:
>>>
>>>           _______________
>>>           |                         |
>>>           |         Plot          |
>>>           |___  __________|
>>>            1931          1932
>>> Month:   01              04
>>>
>>> # R code
>>> require(lattice)
>>> barchart(yield ~ year, data = barley,
>>>   stack=TRUE,
>>>   col="black",
>>>   ylim=c(0,85)
>>> )
>>>
>>
>> Hi Peng,
>> Try using mtext:
>>
>> mtext("Month:  01   04",side=1,line=2,at=0,adj=0)
>>
>> You may have to adjust the last three arguments to get it in the correct
>> position.
>>
>> Jim
>>
>>
>
>        [[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>