[R] xyplot, groups and colors

[David Winsemius]

On Apr 8, 2011, at 8:06 AM, Philipp Pagel wrote:

>
> 	Dear ExpeRts,
>
> I am trying to plot a bunch of growth curves and would like to get
> some more control over groups and line colors than I seem to have.
>
> Example:
>
> # make some data
> dat <- Orange
> dat$group <- ifelse(dat$Tree%in%c('1','4','5'), 'A', 'B')
>
> # plot
> xyplot(circumference~age, dat, groups=group)
>
> # now use lines to make the growth curve more visible
> xyplot(circumference~age, dat, groups=group, type='l')
> # ugly, because of the 'return' lines
>
> # to fix this set groups to Tree
> xyplot(circumference~age, dat, groups=Tree, type='l')
> # better, but now each Tree has its own color
>
> Of course I can now use the col argument to manually assign the colors
> by group but is there a more elegant way that I missed?

You aren't saying what you want but I am guessing it is a color-less  
plot:

xyplot(circumference~age, dat, groups=Tree, type='l',
         par.settings=simpleTheme(col="grey"))

trellis.par.set can also  be used to specify this globally.

-- 
David Winsemius, MD
West Hartford, CT