R help - Dec 2006 - two ggplot and colour=x question

Hi

I am using ggplot with the aesthetic=list(..., colour=x, ...)

ggplot()
ggline()

I have four different values in x ("ren", "cyn",
"mixed", "bare") and I
have two questions

1) I would like to assign specific colours to the values, i.e. green, 
red, blue and brown. How can I do this? I did not understand 
map_colour_brewer.

2) I don't want the legend top be plot. How can I disable the legend to 
be plotted?

Thanks

Rainer

-- 
Rainer M. Krug, Dipl. Phys. (Germany), MSc Conservation
Biology (UCT)

Department of Conservation Ecology and Entomology
University of Stellenbosch
Matieland 7602
South Africa

Tel:		+27 - (0)72 808 2975 (w)
Fax:		+27 - (0)86 516 2782
Fax:		+27 - (0)21 808 3304 (w)
Cell:		+27 - (0)83 9479 042

email:	RKrug at sun.ac.za
       	Rainer at krugs.de

> I am using ggplot with the aesthetic=list(..., colour=x, ...)
>
> ggplot()
> ggline()
>
> I have four different values in x ("ren", "cyn",
"mixed", "bare") and I
> have two questions
>
> 1) I would like to assign specific colours to the values, i.e. green,
> red, blue and brown. How can I do this? I did not understand
> map_colour_brewer.
There's not really an easy way to do this at the moment.  However, you
can create a new variable containing the colours you want to use and
then use a manual scale so they aren't converted automatically:

df$colour <-
c("red","blue","yellow","orange)[df$myvar]
p <- ggplot(data=df, aes=list(x=x,y=y,colour=colour)
scmanual(p, "colour")
> 2) I don't want the legend top be plot. How can I disable the legend to
> be plotted?
If you use a manual scale (as above) there won't be a legend, or more
generally you can do:

p$legend.position <- "none"
to turn of the legend (see ?ggopt for other options)

Hadley