Be careful: I think that's only going to check exact equality: i.e., it won't find 20.5, but it also won't find 19.9999999999997 which you might get when you mean 20 due to floating point error. If the OP has non-integer data, this will cause trouble.
Michael PS -- you also don't need the call to `c` -- there's nothing the 20:30 sequence is being combined with. On Thu, Jan 12, 2012 at 10:50 PM, Schreiber, Stefan <stefan.schrei...@ales.ualberta.ca> wrote: > Or with what I just learned: > > subset<-[mydata$age %in% c(20:30),] > > Thanks for explaining Michael! > > Stefan > > > > > -----Original Message----- > From: r-help-boun...@r-project.org on behalf of Marc Schwartz > Sent: Thu 1/12/2012 8:38 PM > To: R. Michael Weylandt > Cc: r-help@r-project.org; manu79 > Subject: Re: [R] work with a subset of the dataset > > Presuming that 'DF' is the data frame, I am not sure what is wrong with > > NewDF <- subset(DF, (age >= 20) & (age <= 30)) > > presuming that 20 and 30 are to be included. > > ? > > Marc Schwartz > > On Jan 12, 2012, at 9:26 PM, R. Michael Weylandt wrote: > >> You can probably do it more easily with the subset() function but in >> my experience that often leads to more problems than solutions: >> perhaps try this. >> >> idx <- with(DATA, which(age > 20 & age < 30)) >> DATA[idx, ] >> >> Michael >> >> On Thu, Jan 12, 2012 at 5:25 PM, manu79 <manuelespin...@hotmail.it> wrote: >>> Hello, >>> I have a big dataset with many variables and I would like to consider >>> only >>> the rows in which there is a specific value of a variable. >>> >>> I make an example for explain what I mean: >>> I have 5 variables describing a person: age, sex, weight, colour of hair, >>> colour of eyes. >>> I have 1000 rows (1000 persons) and I want to consider only the persons >>> whose age is between 20 to 30. How can I do? >>> >>> Thank you very much >>> M. > > ______________________________________________ > 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. > ______________________________________________ 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.
