Hello, I was wondering if there was a way to only select cases my from data frame that contained a negative value?> c<-c(1,2,3,4,5,6,7,8,9,10) > d<- c(-1,2,-3,-4,5,6,-7,8,-9,10) > f <- cbind(c,d) > dat <-data.frame(f) > dat.lm <-lm(c~d)If I wanted to only use the rows that had a negative value in column d for my regression, how could I make that selection? Thanks, Michael Just

Try this: dat.lm <-lm(c~d, subset=d < 0) On Sat, Oct 18, 2008 at 7:03 PM, Michael Just <mgjust at gmail.com> wrote:> Hello, > I was wondering if there was a way to only select cases my from data > frame that contained a negative value? > >> c<-c(1,2,3,4,5,6,7,8,9,10) >> d<- c(-1,2,-3,-4,5,6,-7,8,-9,10) >> f <- cbind(c,d) >> dat <-data.frame(f) >> dat.lm <-lm(c~d) > > If I wanted to only use the rows that had a negative value in column d > for my regression, how could I make that selection? > > Thanks, > Michael Just > > ______________________________________________ > 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-Paran?-Brasil 25? 25' 40" S 49? 16' 22" O

Am 18.10.2008 um 23:03 schrieb Michael Just:> Hello, > I was wondering if there was a way to only select cases my from data > frame that contained a negative value? > >> c<-c(1,2,3,4,5,6,7,8,9,10) >> d<- c(-1,2,-3,-4,5,6,-7,8,-9,10) >> f <- cbind(c,d) >> dat <-data.frame(f) >> dat.lm <-lm(c~d) > > If I wanted to only use the rows that had a negative value in column d > for my regression, how could I make that selection? > >untested: dat[dat$d < 0, ]

Johannes, Thanks for the response. However, ...> dat.neg <- dat[dat$d < 0, ]Error in dat[dat$d < 0, ] : incorrect number of dimensions In addition: Warning message: $ operator is deprecated for atomic vectors, returning NULL in: dat$d Any other ideas? Thanks, Michael On Sat, Oct 18, 2008 at 5:18 PM, Johannes H?sing <johannes at huesing.name> wrote:> > Am 18.10.2008 um 23:03 schrieb Michael Just: > >> Hello, >> I was wondering if there was a way to only select cases my from data >> frame that contained a negative value? >> >>> c<-c(1,2,3,4,5,6,7,8,9,10) >>> d<- c(-1,2,-3,-4,5,6,-7,8,-9,10) >>> f <- cbind(c,d) >>> dat <-data.frame(f) >>> dat.lm <-lm(c~d) >> >> If I wanted to only use the rows that had a negative value in column d >> for my regression, how could I make that selection? >> >> > > untested: > dat[dat$d < 0, ] > >