Re: [R] No years() function?
>From the help of weekdays: "Note: Other components such as the day of the month or the year are very easy to compute: just use 'as.POSIXlt' and extract the relevant component." Yet another option: help(package="chron") JR El mié, 07-03-2007 a las 15:35 +, Sérgio Nunes escribió: > Hi, > > I'm trying to aggregate date values using the aggregate function. For example: > > aggregate(data,by=list(weekdays(LM),months(LM)),FUN=length) > > I would also like to aggregate by year but there seems to be no > years() function. > Should there be one? Is there any alternative choice? > > Also, a hours() function would be great. Any tip on this? > > Thanks in advance! > Sérgio Nunes > > __ > R-help@stat.math.ethz.ch 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. -- Dipl.-Biol. JR Ferrer Paris ~~~ Laboratorio de Biología de Organismos --- Centro de Ecología Instituto Venezolano de Investigaciones Científicas (IVIC) Apdo. 21827, Caracas 1020-A República Bolivariana de Venezuela Tel: (+58-212) 504-1452 Fax: (+58-212) 504-1088 email: [EMAIL PROTECTED] clave-gpg: 2C260A95 __ R-help@stat.math.ethz.ch 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.
Re: [R] No years() function?
Sérgio Nunes gmail.com> writes:
>
> Hi,
>
> I'm trying to aggregate date values using the aggregate function. For example:
>
> aggregate(data,by=list(weekdays(LM),months(LM)),FUN=length)
>
> I would also like to aggregate by year but there seems to be no
> years() function.
> Should there be one? Is there any alternative choice?
>
> Also, a hours() function would be great. Any tip on this?
>
> Thanks in advance!
> Sérgio Nunes
>
Well, working by analogy with the existing
functions, this might work (not messing with
setting up an S3 default though):
> apropos("weekdays")
[1] "weekdays""weekdays.Date" "weekdays.POSIXt"
> weekdays.Date
function (x, abbreviate = FALSE)
format(x, ifelse(abbreviate, "%a", "%A"))
d1 = Sys.time()
years <- function(x,abbreviate=FALSE) {
as.numeric(format(x, ifelse(abbreviate, "%y", "%Y")))
}
hours <- function(x) {
as.numeric(format(x,"%H"))
}
years(d1); hours(d1)
__
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PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
