Sebastien, My understanding is the argument of c==1 in subset() is actually to evaluate foo$c==1, which returns a vector of logical values. Try this,
mystr<-foo$c==1 subset(foo,mystr) Jun On Fri, Aug 21, 2009 at 3:21 PM, Sebastien Bihorel < sebastien.biho...@cognigencorp.com> wrote: > Dear R-users, > > The following question bothered me for the whole afternoon: how can one > pass a string as the conditioning argument to subset? I tried plain mystr, > eval(mystr), expression(mystr), etc... I don't to be able to find the > correct syntax > > > foo <- data.frame(a=1:10,b=10:1,c=rep(1:2,5)) > > mystr<-"c==1" > > subset(foo,c==1) > a b c > 1 1 10 1 > 3 3 8 1 > 5 5 6 1 > 7 7 4 1 > 9 9 2 1 > > subset(foo,mystr) > Error in subset.data.frame(foo, mystr) : > 'subset' must evaluate to logical > > > > Any help would be greatly appreciated. > > Sebastien > > ______________________________________________ > 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. > -- Jun Shen PhD PK/PD Scientist BioPharma Services Millipore Corporation 15 Research Park Dr. St Charles, MO 63304 Direct: 636-720-1589 [[alternative HTML version deleted]] ______________________________________________ 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.
