[R] Trellis Plot Labels

[Deepayan Sarkar]

On 12/6/06, Turgut Durduran <durduran at yahoo.com> wrote:
>
>
> ----- Original Message ----
> From: Deepayan Sarkar <deepayan.sarkar at gmail.com>
> To: Turgut Durduran <durduran at yahoo.com>
> Cc: r-help at stat.math.ethz.ch
> Sent: Saturday, November 18, 2006 4:28:03 PM
> Subject: Re: Re: [R] Trellis Plot Labels
>
> On 11/17/06, Deepayan Sarkar <deepayan.sarkar at gmail.com> wrote:
> > On 11/17/06, Turgut Durduran <durduran at yahoo.com> wrote:
> > > On 11/17/06, Turgut Durduran <durduran at yahoo.com> wrote:
> > > >> Hello everyone,
> > > >>
> > > >> I am ploting a groupeddata object with formula:
> > > >>
> > > >> formula(mydatausegroup)
> > > >> BF ~ HO | ID/Infar/Day
> > > >>
> > > >> Using this command:
> > > >> plot(na.omit(mydatausegroup), displayLevel=2,layout=c(10,2),aspect=2)
> > > >>
> > > >>
> > > >> This trellis plot does almost what I want and produces a 10x2 trellis plot, each panel is labeled
> > > >> as ID/Infar where infarct is either 1 or 0. And in each panel, it plots BF vs HO for each Day. However, the "days" are labeled simply as "1,2,3,4" i>>nstead of their actual values (ranging from 1 to 8). This just mapped for each ID the "1 st measurement, 2nd measurement, 3rd measurement, 4th >>measurement".
> > > >>
> >
> > This seems to be intended behaviour, and the responsible function is
> > collapse.groupedData (which is not very transparent to me).
> >
> > > >> How can I get this trellis plot to use 8 different colors and label them correct?
> >
> > I don't see a documented way, so you'll probably need to modify
> > collapse.groupedData
>
> >>I should have added: it's of course fairly easy if you use xyplot directly.
>
>
> Thank you very much for your detailed help. However, in xyplot, I am ending up a whole bunch of empty panels corresponding to missing days. For example if I did:
>  xyplot(CBF~OB|Day*Inf*ID,data=na.omit(mydatausegroup))

In this case, the plot will have one panel for every combination of
non-empty levels of Day, Inf and ID (not every non-empty combination
of levels). In your case, if you have a nested structure where the
levels of Inf and ID don't mean anything individually. You should be
using an interaction, e.g.

xyplot(CBF~OB|Day:Inf:ID,data=na.omit(mydatausegroup))

To xyplot, the difference is that there is now one conditioning
variable rather than 3, and it will omit any empty levels.

-Deepayan