Clearly the poor user needs to export something to one of those archaic stats systems like SAS or SPSS :)
--- On Tue, 8/18/09, Bert Gunter <gunter.ber...@gene.com> wrote: > From: Bert Gunter <gunter.ber...@gene.com> > Subject: RE: [R] Replacing NA values in one column of a data.frame > To: "'Steve Lianoglou'" <mailinglist.honey...@gmail.com>, "'John Kane'" > <jrkrid...@yahoo.ca> > Cc: r-help@r-project.org, "'Steve Murray'" <smurray...@hotmail.com> > Received: Tuesday, August 18, 2009, 11:27 AM > > > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] > On > Behalf Of Steve Lianoglou > Sent: Tuesday, August 18, 2009 7:25 AM > To: John Kane > Cc: r-help@r-project.org; > Steve Murray > Subject: Re: [R] Replacing NA values in one column of a > data.frame > > > ...** But do NOT do this.*** Unless you are using R > to prepare your data > for some other statistical analysis system (most unwise), > there is **never** > any reason in R to replace NA's with nonsense numerical > codes -- and a great > many reasons NOT to do this, to whit: > > 1) NA's are a special value in R (actually many, of > different types) with > extensive built-in capabilities to handle them properly, > deal with them > (often automatically) in fitting functions etc. Recoding to > a nonsense > numeric defeats all this careful machinery. > > 2) You are just begging for trouble by using nonsense > numerics: if you > forget your coding or someone else uses your data who's not > aware of it, > voilá ! -- you have just guaranteed that data analyses > will be partial or > complete garbage. > > Finally -- a request to well-meaning helpeRs: Just because > you CAN do > something in R statistically or programmatically does not > mean you should. > When someone requests something that you believe is the > wrong thing to do, I > think it within the bounds of both R etiquette and > professional practice to > tell them NOT to do it and explain why not. Of course, > sometimes such > admonitions are themselves ill-advised (as this may be), > but an open, > courteous, professional exchange on the issue will itself > be informative to > useRs. > > Cheers to all, > > Bert > > Bert Gunter > Genentech Nonclinical Biostatisics > > > > > __________________________________________________________________ Make your browsing faster, safer, and easier with the new Internet Explorer® 8. Optimized for Yahoo ______________________________________________ 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.
