Yes and yes. To be clear,
1. sum() is better. 2. xtabs is better (I just forgot about it and didn't bother to search). Maybe the best answer is in fact, ??crosstabulation which would have brought up xtabs(). So the moral is (to the OP), learn how to search before posting. Cheers, Bert Bert Gunter "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." -- Clifford Stoll On Thu, Aug 13, 2015 at 8:18 AM, peter dalgaard <[email protected]> wrote: > >> On 13 Aug 2015, at 16:24 , Bert Gunter <[email protected]> wrote: >> >> Well, just using base R, ... >> >>> with(mydata,tapply(freq,list(var1,var2),I)) >> 0 1 >> 0 11 12 >> 1 13 14 > > If you insist on avoiding the stats package... > > However, I'd use sum() rather than I() to get an xtabs() workalike. > > -pd > >> >> >> Cheers, >> Bert >> >> >> Bert Gunter >> >> "Data is not information. Information is not knowledge. And knowledge >> is certainly not wisdom." >> -- Clifford Stoll >> >> >> On Thu, Aug 13, 2015 at 6:39 AM, Sarah Goslee <[email protected]> wrote: >>> Hi, >>> >>> There are lots of ways to do it in base R, but a long time ago I got >>> frustrated and wrote a crosstab function that did exactly what I >>> wanted: >>> >>> library(ecodist) >>> mydata <- data.frame(var1=c(0,0,1,1),var2=c(0,1,0,1),freq=c(11,12,13,14)) >>> crosstab(var1, var2, freq, data=mydata) >>> >>> 0 1 >>> 0 11 12 >>> 1 13 14 >>> >>> Sarah >>> >>> On Thu, Aug 13, 2015 at 5:30 AM, Dean1 <[email protected]> wrote: >>>> Hi all, >>>> >>>> I've had a few years experience with R, which is why this is so >>>> frustrating, >>>> my problem seems so simple but I can't find a solution. >>>> >>>> I have a data frame in the following form: >>>> >>>> data.frame(var1=c(0,0,1,1),var2=c(0,1,0,1),freq=c(11,12,13,14)) >>>> >>>> How do I create a crosstab with frequencies? >>>> 0 1 >>>> 0: 11 12 >>>> 1: 13 14 >>>> >>>> >>> >>> -- >>> Sarah Goslee >>> http://www.functionaldiversity.org >>> >>> ______________________________________________ >>> [email protected] mailing list -- To UNSUBSCRIBE and more, see >>> 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. >> >> ______________________________________________ >> [email protected] mailing list -- To UNSUBSCRIBE and more, see >> 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. > > -- > Peter Dalgaard, Professor, > Center for Statistics, Copenhagen Business School > Solbjerg Plads 3, 2000 Frederiksberg, Denmark > Phone: (+45)38153501 > Email: [email protected] Priv: [email protected] > > > > > > > > ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see 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.
