Your problem is that columns A & B contain something that can't be ordered. (Likely "factor" (=categorical) data like Male / Female rather than numeric like 10 and 5)
Use str(data_2) to see what classes your data are -- they sometimes get converted in unexpected ways if you aren't careful in setting up your data.frame. If this doesn't clear things up, please type dput(head(data_2, 20)) at the console and copy and paste the result into a follow up email. Don't do the data.matrix thing without understanding the current class of your data -- you'll get strange conversions. Hope this helps, Michael On Wed, Apr 18, 2012 at 8:36 AM, Dwaipayan Dasgupta <dwaipayan.dasgu...@aexp.com> wrote: > Hi, > I am stuck with creating a conditional categorical variable in R > If my dataframe data_2 has 3 variables A,B,C I want to create variable D > which would be something like : > > data_2$D <- ifelse(data_2$A < data_2$B & promotion_ind =="N",1,0), > this throws up an error "In Ops.factor(data_2$A,data_2$B) : > < not meaningful for factors > > I have tried converting the dataframe to a matrix using > data.matrix(data_2, rownames.force = NA) but that did not help, > > Can anybody tell me how to go about doing this? > > Thanks in advance, > Doy > > American Express made the following annotations on Wed Apr 18 2012 05:37:16 > > ****************************************************************************** > > "This message and any attachments are solely for the intended recipient and > may contain confidential or privileged information. If you are not the > intended recipient, any disclosure, copying, use, or distribution of the > information included in this message and any attachments is prohibited. If > you have received this communication in error, please notify us by reply > e-mail and immediately and permanently delete this message and any > attachments. Thank you." > > American Express a ajouté le commentaire suivant le Wed Apr 18 2012 05:37:16 > > Ce courrier et toute pièce jointe qu'il contient sont réservés au seul > destinataire indiqué et peuvent renfermer des renseignements confidentiels et > privilégiés. Si vous n'êtes pas le destinataire prévu, toute divulgation, > duplication, utilisation ou distribution du courrier ou de toute pièce jointe > est interdite. Si vous avez reçu cette communication par erreur, veuillez > nous en aviser par courrier et détruire immédiatement le courrier et les > pièces jointes. Merci. > > ****************************************************************************** > ------------------------------------------------------------------------------- > > > [[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.
