On May 11, 2010, at 8:38 PM, Noah Silverman wrote:
Hi,
An example data set is:
group level color
A 1 "blue"
A 1 "Red"
B 1 "blue"
B 2 "Red"
A 2 "Red"
B 2 "Red"
B 2 "blue"
B 2 "blue"
A 2 "blue"
A 2 "Red"
I'd like to compute a summary of counts for each combination of
group, level, color.
An example output would be something like this:
group level color count
A 1 "blue" 1
A 2 "red" 2
B 2 "red" 2
etc..
The tapply function seems to do this for a single variable, but I
can figure out to to do it for combinations of more than one factor.
This doesn't work?
tapply(example$color, c(example$group, example$level), length)
I also see the ave function, but can't figure out how to apply it to
multiple factors.
It would give you as man lines as in the orignal which is not what you
want.
--
David,
Any suggestions?
Thanks
______________________________________________
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.
David Winsemius, MD
West Hartford, CT
______________________________________________
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.
