How does one overcome overlapping points without jitter or transparency in ggplot2

Question

I am starting to use ggplot2. I have some small n (about 30 or so) granular data with lots of overlap. Neither jitter nor alpha (transparency) are suitable. Instead a stripchart

Answer 1

You want to use geom_dotplot from ggplot2

you will probably want to use:

ggplot(insert your arguments here) + geom_dotplot(binaxis = "y", stackdir = "center")

Hope this helps. The results will look really clean which is what I think you want.

Answer 2

You can use position_dodge.

df <- data.frame(gp = rep(LETTERS[1:5], each =8), 
                 y = sample(1:4,40,replace=TRUE))
qplot(gp,y,data=df,order=y,position=position_dodge(width=0.5))

alt text http://img100.imageshack.us/img100/8760/dodgel.png

Answer 3

# your data
df <- data.frame(gp = rep(LETTERS[1:5], each =8), y = sample(1:4,40,replace=TRUE))
# calculate offsets
df <- ddply(df, .(y, gp), transform, offset = (1:length(gp)-1)/20)
qplot(gp, y, data=df) + stat_identity(aes(as.numeric(gp)+offset)) + theme_bw()