On 3/7/07, Peter Dalgaard <[EMAIL PROTECTED]> wrote: > Jason Barnhart wrote: > > ----- Original Message ----- > > From: "John Kane" <[EMAIL PROTECTED]> > > To: "lamack lamack" <[EMAIL PROTECTED]>; <[email protected]> > > Sent: Tuesday, March 06, 2007 2:13 PM > > Subject: Re: [R] R and SAS proc format > > > > > > > >> --- lamack lamack <[EMAIL PROTECTED]> wrote: > >> > >> > >>> Dear all, Is there an R equivalent to SAS's proc > >>> format? > >>> > >> What does the SAS PROC FORMAT do? > >> > > > > It formats or reformats data in the SAS system. > > > > Slightly more precisely: It creates user-defined formats, which are > subsequently associated with variables and used for reading, printing, > tabulating, and analyzing data. It is akin to R's factor() > constructions, but not quite. For one thing, SAS's formats are separate > entities - same format can be used for many variables, whereas R's > factors have the formatting coded as a part of the object. For related > reasons, a variable in SAS can have more distinct values than there are > value labesl for, etc. > > It looks this: > > > > proc format; value kanefmt 1='A' 2='B' 3='C' 4='X' 5='Throw me > > out'; > > data temp; do i=1 to 10; kanevar=put(i,kanefmt.); output; end; > > proc print; run; > > > > And produces this: > > > > Obs i kanevar > > 1 1 A > > 2 2 B > > 3 3 C > > 4 4 X > > 5 5 Throw me out > > 6 6 6 > > 7 7 7 > > 8 8 8 > > 9 9 9 > > 10 10 10 > > > > > > But it is more robust than what is shown here. > > > > > > > > > >> ______________________________________________ > >> [email protected] 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. > >> > >> > > > > ______________________________________________ > > [email protected] 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. > > > > > -- > O__ ---- Peter Dalgaard Øster Farimagsgade 5, Entr.B > c/ /'_ --- Dept. of Biostatistics PO Box 2099, 1014 Cph. K > (*) \(*) -- University of Copenhagen Denmark Ph: (+45) 35327918 > ~~~~~~~~~~ - ([EMAIL PROTECTED]) FAX: (+45) 35327907 > > ______________________________________________ > [email protected] 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. >
Also, SAS formats are used as a (somewhat cumbersome) replacement for "dictionary" data structures. Starting from SAS 9.1 (I believe), "hash tables" can be used within data steps for the same purpose (albeit still cumbersome). In this regard, not only formats but also lists could be a replacement for them. They can be used as a way to get key-value mappings. These key-value mappings (I mean, these kind of data structures) are very handy tools. I have used both factors and lists for some kind of "ad hoc" replacement for these data structures. Hasn't anybody considered the posibility of having these data structures implemented in R in a much python-like or java-like touch and feel? Regards, Carlos J. Gil Bellosta http://www.datanalytics.com ______________________________________________ [email protected] 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.
