On Sun, 01-Nov-2009 at 01:20AM -0500, Jason Priem wrote:
> I've got a data frame describing comments on an electronic journal,
> wherein each row is a unique comment, like so:
>
> commentID author articleID
> 1 1 smith 2
> 2 2 jones 3
> 3 3 andrews 2
> 4 4 jones 1
> 5 5 johnson 3
> 6 6 smith 2
Let's call that dataframe x
>
> I want know the number of unique authors per article. I can get a table
> of article frequencies with table(articleID), but I can't figure out how
> to count frequencies in a different column. I'm sure there's an easy
> way, but I guess I'm too new at this to find it.
I'm not clear what you require, but maybe it's this:
> with(x, table(articleID, author))
articleID andrews johnson jones smith
1 0 0 1 0
2 1 0 0 2
3 0 1 1 0
Is that anything like what you're after?
--
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
___ Patrick Connolly
{~._.~} Great minds discuss ideas
_( Y )_ Average minds discuss events
(:_~*~_:) Small minds discuss people
(_)-(_) ..... Eleanor Roosevelt
~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.~.
______________________________________________
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.
