On Sun, 19 Feb 2006, Evgeniy Kachalin wrote:
Hello, dear R users.
What is the easiest and the most visualli understandable way to analize
dependency of numerical variable on two factors?
interaction.plot() is a good start.
Is the
boxplot(y~f1+f2) the good way? It seems that this formula does not work.
No, nor is it documented to: the help page is there to help you. You
need a single factor as the grouping, so make one via an interaction.
boxplot(y ~ f1:f2) should work. E.g.
library(MASS)
boxplot(FL ~ sex:sp, data=crabs)
Another idea is to use lattice's bwplot. E.g.
library(lattice)
bwplot(FL ~ sex | sp, data=crabs)