[Rd] aggregate() does not return POSIXct object correctly (PR#12887)
Full_Name: Rene Locher Version: 2.7.2 Patched (2008-09-12 r46541) OS: XP Submission from: (NULL) (160.85.231.40) dat - data.frame(event=factor(c(A,A,B)), time=as.POSIXct(c(2008-01-10,2008-01-01,2008-01-04))) min(dat$time) ## 2008-01-01 CET ## as expected aggregate(dat$time,by=list(event=dat$event),min) ## results in ##event x ## 1 A 1199142000 ## 2 B 1199401200 ## I expected: ##eventx ## 1 A 2008-01-01 CET ## 2 B 2008-01-04 CET ## my system: sessionInfo() ## R version 2.7.2 Patched (2008-09-12 r46541) ## i386-pc-mingw32 ## ## locale: ## LC_COLLATE=German_Switzerland.1252;LC_CTYPE=German_Switzerland.1252;LC_MONETARY=German_Switzerland.1252;LC_NUMERIC=C;LC_TIME=German_Switzerland.1252 ## ## attached base packages: ## [1] stats graphics grDevices utils datasets methods base Kind regards Rene Locher E-Mail: [EMAIL PROTECTED] Institute for Data Analysis and Process Design Tel:+41 58 934 7810 Zurich University of Applied Sciences Fax:+41 58 935 7810 Rosenstrasse 3 Postfach CH-8401 Winterthurhttp://www.idp.zhaw.ch __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] aggregate() does not return POSIXct object correctly (PR#12887)
[EMAIL PROTECTED] wrote: Full_Name: Rene Locher Version: 2.7.2 Patched (2008-09-12 r46541) OS: XP Submission from: (NULL) (160.85.231.40) dat - data.frame(event=factor(c(A,A,B)), time=as.POSIXct(c(2008-01-10,2008-01-01,2008-01-04))) min(dat$time) ## 2008-01-01 CET ## as expected aggregate(dat$time,by=list(event=dat$event),min) ## results in ##event x ## 1 A 1199142000 ## 2 B 1199401200 ## I expected: ##eventx ## 1 A 2008-01-01 CET ## 2 B 2008-01-04 CET This is as documented, possibly annoying, but not a bug. aggregate() is documented to build on tapply() for which the discarding of class is documented on ?tapply. The root cause is unlist(): tapply(dat[[time]],dat$event,min,simplify=FALSE) $A [1] 2008-01-01 CET $B [1] 2008-01-04 CET unlist(tapply(dat[[time]],dat$event,min,simplify=FALSE)) A B 1199142000 1199401200 and a partial rationale is that unlist() wouldn't know what to do if the arguments had different classes. The workaround is, of course, just to stick the class back on. -- 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 __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
Re: [Rd] aggregate() does not return POSIXct object correctly (PR#12887)
On Tue, Sep 16, 2008 at 11:22 AM, Peter Dalgaard [EMAIL PROTECTED] wrote: [EMAIL PROTECTED] wrote: Full_Name: Rene Locher Version: 2.7.2 Patched (2008-09-12 r46541) OS: XP Submission from: (NULL) (160.85.231.40) dat - data.frame(event=factor(c(A,A,B)), time=as.POSIXct(c(2008-01-10,2008-01-01,2008-01-04))) min(dat$time) ## 2008-01-01 CET ## as expected aggregate(dat$time,by=list(event=dat$event),min) ## results in ##event x ## 1 A 1199142000 ## 2 B 1199401200 ## I expected: ##eventx ## 1 A 2008-01-01 CET ## 2 B 2008-01-04 CET This is as documented, possibly annoying, but not a bug. aggregate() is documented to build on tapply() for which the discarding of class is documented on ?tapply. The root cause is unlist(): tapply(dat[[time]],dat$event,min,simplify=FALSE) $A [1] 2008-01-01 CET $B [1] 2008-01-04 CET unlist(tapply(dat[[time]],dat$event,min,simplify=FALSE)) A B 1199142000 1199401200 and a partial rationale is that unlist() wouldn't know what to do if the arguments had different classes. The workaround is, of course, just to stick the class back on. Another workaround is: https://stat.ethz.ch/pipermail/r-help/2008-September/173139.html __ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
