[R] Count values in a dataframe with respect to groups

Marcus Drescher drescher at tum.de
Fri Oct 8 17:13:33 CEST 2010


I am sorry for the typo, it is about counting two columns an skipping the NAs.

How would I have to set the formula if I would have two columns to count (val1 and val2)?


Betreff: Re: [R] Count values in a dataframe with respect to groups

Try this:

aggregate(val ~ grp, dta, length)

On Fri, Oct 8, 2010 at 11:28 AM, Marcus Drescher <drescher at tum.de> wrote:
Dear all,

I am looking for a function to count values belonging to a class within a dataframe (and ignore NAs).

grp = c(1,1,1, 1,2, 2,2)
val = c(2,1,5,NA,3,NA,1)

dta = data.frame(grp=grp, val=val)

The result should look like:

grp count
 1    3
 2    2

At the moment, I am trying to find a function for FUN in aggregate, but with no success. Can anybody help me?

Thanks in advance.
Marcus

______________________________________________
R-help at 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.



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O



More information about the R-help mailing list