> -----Original Message----- > From: r-devel-boun...@r-project.org [mailto:r-devel-boun...@r-project.org] > On Behalf Of Jeffrey Ryan > Sent: January-31-12 12:47 PM > To: Dirk Eddelbuettel > Cc: R-devel org > Subject: Re: [Rd] seq.Date bug? > > format(ISOdate(2012,1:12,1),"%b-%Y") > > [1] "Jan-2012" "Feb-2012" "Mar-2012" "Apr-2012" "May-2012" "Jun-2012" > [7] "Jul-2012" "Aug-2012" "Sep-2012" "Oct-2012" "Nov-2012" "Dec-2012" > > First of the month is just as clean, and AFAIR they all have a first ;-)
>From which you can get the last... > format(ISOdate(2012,1:12,1)-86400,"%d-%b-%Y") [1] "31-Dec-2011" "31-Jan-2012" "29-Feb-2012" "31-Mar-2012" "30-Apr-2012" "31-May-2012" [7] "30-Jun-2012" "31-Jul-2012" "31-Aug-2012" "30-Sep-2012" "31-Oct-2012" "30-Nov-2012" ... though leap seconds might require a bit more tweaking... Steven McKinney Statistician Molecular Oncology and Breast Cancer Program British Columbia Cancer Research Centre > > Jeff > > On Tue, Jan 31, 2012 at 2:37 PM, Dirk Eddelbuettel <e...@debian.org> wrote: > > > > On 31 January 2012 at 15:17, Duncan Murdoch wrote: > > | On 12-01-31 2:56 PM, Dirk Eddelbuettel wrote: > > | > > > | > R> seq(as.Date(Sys.Date()), by="-1 months", length=6) > > | > [1] "2012-01-31" "2011-12-31" "2011-12-01" "2011-10-31" "2011-10-01" > "2011-08-31" > > | > R> > > | > > > | > Notice how October appears twice. > > | > > | > > > | > Now, date arithmetic is gruesome but the documentation for seq.Date > et al > > | > does not hint it wouldn't honour the by= argument. So a bug, or > merely a > > | > somewhat less than desirable features. > > | > > | It is giving you Jan 31, Dec 31, Nov 31, Oct 31, Sep 31, Aug 31 -- > > | except some of those months don't have 31 days, so it is converting > > | those dates to ones that really exist. (This is documented in > ?seq.POSIXt.) > > | > > | Isn't this what you asked for? > > > > No as I was feeding this into format(..., "%b-%y") to create 'pretty' > names, > > and the double entries screw that. > > > > Morale: pick a mid-month date, and shift that. > > > > Dirk > > > > | Duncan Murdoch > > | > > | > > | > > > | > (And yes, I think I know that Hadley's lubridate has code for this > too, but > > | > so may my RcppBDT which is sitting on top of Boost::DateTime code > ...) > > | > > > | > Dirk > > | > > > | > > > > -- > > "Outside of a dog, a book is a man's best friend. Inside of a dog, it is > too > > dark to read." -- Groucho Marx > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel > > > > -- > Jeffrey Ryan > jeffrey.r...@lemnica.com > > www.lemnica.com > www.esotericR.com > > R/Finance 2012: Applied Finance with R > www.RinFinance.com > > See you in Chicago!!!! > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
