[R] Overlaying several qqnorm curves in same frame

[Deepayan Sarkar]

On 1/6/09, Assaf oron <assaf.oron at gmail.com> wrote:
> Hi all,
>
>  I want to create a rather standard overlaid qqnorm plot on a single
>  variable, with different subgroups of the same dataset plotted using
>  different colors/symbols/etc. (I don't want side-by-side, rather
>  different-colored curves on the same graph)
>
>  I managed to do it rather tediously using "lapply" and "split", and wondered
>  whether there is any single-command shortcut. Is there anything on the
>  "lattice" package perhaps?

Yes, use qqmath(~x, groups=...), e.g.,

qqmath(~ height, data = singer, groups = voice.part, auto.key = TRUE)

-Deepayan