I don't know if my recent post on this prompted your post, but I don't see much to argue with in your discussion. I find factors to be useful for managing display and some kinds of analysis.
However, I find them mostly a handicap when importing, merging, and handling data QC. Therefore I delay conversion until late in the game... but usually I do eventually convert in most cases. --------------------------------------------------------------------------- Jeff Newmiller The ..... ..... Go Live... DCN:<jdnew...@dcn.davis.ca.us> Basics: ##.#. ##.#. Live Go... Live: OO#.. Dead: OO#.. Playing Research Engineer (Solar/Batteries O.O#. #.O#. with /Software/Embedded Controllers) .OO#. .OO#. rocks...1k --------------------------------------------------------------------------- Sent from my phone. Please excuse my brevity. Bert Gunter <gunter.ber...@gene.com> wrote: >Folks: > >Over the years, many people -- including some who I would consider >real expeRts -- have criticized factors and advocated the use >(sometimes exclusively) of character vectors instead. I would just >like to point out that, for me, factors provide one feature that I >find to be very convenient: ordering of levels. ** > >As an example, suppose one has a character vector of labels "small," >medium", and "large". Then most R functions (e.g. tapply()) will >display results involving this vector in alphabetical order, which I >think most would view as undesirable. By converting to a factor with >levels in the logical order, displays will automatically be "logical." >For example: > >> x <- sample(c("small","medium","large"),12,rep=TRUE) >> table(x) >x > large medium small > 2 3 7 >> y <- factor(x,lev=c("small","medium","large")) ##ordered() also would >do, but is not necessary for this >> table(y) >y > small medium large > 7 3 2 > >Naturally, this is just my opinion, and I understand why lots of smart >people find factors irritating (at least!). So contrary opinions >cheerily welcomed. But perhaps these comments might be helpful to >those who have been "bitten" by factors or just wonder what all the >fuss is about. > >** Another advantage is reduced storage space, I believe. Please >correct if wrong. > >Cheers, >Bert > >-- > >Bert Gunter >Genentech Nonclinical Biostatistics > >Internal Contact Info: >Phone: 467-7374 >Website: >http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm > >______________________________________________ >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.