[R] Need help using lattice

[Gerrit Draisma]

David,
Is this what you are looking for?
library(lattice)
df <- expand.grid(site=c("een","twee","drie","vier","vijf"),
                  month=1:12)
df$conc <- rnorm(dim(df)[1])
dotplot(month~conc|site,data=df)

HTH Gerrit