Thanks, but why does f[f=4] yield 16 instead of 4? > f [1] -2 4 -8 16 -32 64 -128 > f[f<0] [1] -2 -8 -32 -128 > f[f>0] [1] 4 16 64 > f[f=4] [1] 16
2013/5/8 Jorge I Velez <jorgeivanve...@gmail.com> > f [ f < 0 ] > > > On Wed, May 8, 2013 at 11:54 AM, jpm miao <miao...@gmail.com> wrote: > >> Hi, >> >> I have a vector f with some negative columns. I remember that there is >> an easy expression that can find out negative items. Can someone tell me >> how I can do it? >> >> It seems to be >> f[i such that f[i]<0 ...] >> >> Thanks, >> >> Miao >> >> > d<-1:7 >> > f<-(-2)^d >> > f >> [1] -2 4 -8 16 -32 64 -128 >> >> [[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. >> > > [[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.