Gianni, Is this what you are looking for?
mydata$limit2 <- mydata$limit * 2 mydata[mydata$H > mydata$limit2, ] Robert On Thu, Oct 21, 2010 at 9:06 AM, gianni lavaredo <gianni.lavar...@gmail.com> wrote: > Dear Researchers, > > sorry If I ask a simple question, but this night I have no idea to resolv > this question. I have a data.frame (just a simple example) > > > mydata <- data.frame(id=c(1,1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4,5,5,5,5,5), > H=c(1,30,43,67,33,78,90,45,4,8,34,3,82,94,12,15,62,89,3,56,96,3), > limit=c(4,4,4,4,4,3,3,3,3,6,6,6,6,7,7,7,7,8,8,8,8,8)) > > > i wish to select by "id" the row with "H" value >= of the boulde of limit (H >>= limit*2) to have a new data.frame > > mydata > id H limit limit2 > 2 1 30 4 8 > 3 1 43 4 8 > 4 1 67 4 8 > 5 1 33 4 8 > 6 2 78 3 6 > 7 2 90 3 6 > 8 2 45 3 6 > 11 3 34 6 12 > 13 3 82 6 12 > 14 4 94 7 14 > 16 4 15 7 14 > 17 4 62 7 14 > 18 5 89 8 16 > 20 5 56 8 16 > 21 5 96 8 16 > > > thanks and sorry for desturb with easy question > > gianni > > [[alternative HTML version deleted]] > > _______________________________________________ > R-sig-Geo mailing list > R-sig-Geo@stat.math.ethz.ch > https://stat.ethz.ch/mailman/listinfo/r-sig-geo > _______________________________________________ R-sig-Geo mailing list R-sig-Geo@stat.math.ethz.ch https://stat.ethz.ch/mailman/listinfo/r-sig-geo