It seems to be dependent upon the the character ("assigned alphabetically") which I found out by manually changing the order of appearance of the characters in rfactor; the colour would stick to the character "a", whether this appears first in rfactor or not.
I as able to control the colours being used by > boxplot(x~rfactor, col=c("2", "6", "3","5","4")) Rgds, Rainer Disclaimer: I'm new to R and very early on the learning curve - just trying my best... On Saturday 04 December 2010 01:22:56 Eduardo Klein wrote: > Hi, > > I would like to know how R assigns the numeric code to a set of factors > in a vector. For example, I have a vector of 5 different factors in a > random order, and I want a color-coded plot by factors: > > rfactor=as.factor(sample(letters[1:5], 50, replace=T)) > rfactor > [1] c c c d b a b d d a a e e b b e c e e a a b b b a b a e a a b d b > b c a b b > [39] d c a e c d e d a a a a > Levels: a b c d e > > x=rnorm(50) > boxplot(x~rfactor, col=1:5) > > So, colors 1 to 5 are assigned to factors alphabetically (a-1, b-2, ..., > e-5), or by order of appearance (c-1, d-2, b-3, a-4, e-5)? It is > possible to control that? > > Saludos, EKS > > ______________________________________________ R-help@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.