Also check ?aggregate
--- On Wed, 4/6/08, Ingmar Visser <[EMAIL PROTECTED]> wrote: > From: Ingmar Visser <[EMAIL PROTECTED]> > Subject: Re: [R] splitting data frame based on a criteria > To: "Marvin Lists" <[EMAIL PROTECTED]> > Cc: r-help@r-project.org > Received: Wednesday, 4 June, 2008, 5:11 AM > ?by may be helpful here > eg if dat is your data.frame and yf is a factor (created > using ifelse) > use by(dat,yf,mean) to compute the means for each level of > yf > hth, Ingmar > > On Jun 3, 2008, at 8:37 PM, Marvin Lists wrote: > > > Hi, > > I have a data frame that I want to split into two > based on the > > values of a > > variable in it. > > > > The variable Y has numeric values ranging between 0 > through 70. I > > want to > > plot the frequencies of another variable X in two > different cases: > > - When Y = 0 and > > - When Y > 0 > > > > How does one go about doing this? > > > > In general, I want to do several analyses with this > data frame that > > are a > > variation of the above situation, i.e. they require > splitting the > > data into > > different age, gender etc. and then calculating > separate means, > > correlations > > and so on for the different groups into which the data > frame would > > split. > > > > I am struggling with the correct syntax for achieving > this. > > > > Reading through the documentation suggests that tapply > and split > > may be the > > functions to use for my purposes but the examples in > the > > documentations > > didn't help me understand how I could achieve > this. > > > > I would appreciate any suggestions and help. > > > > Thanks, > > Marvin > > > > [[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. > > ______________________________________________ > 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.