Re: [R] Incompatible methods ("+.Date", "Ops.difftime") for "+"

From: Gabor Grothendieck <ggrothendieck_at_gmail.com>
Date: Wed, 25 Jun 2008 01:00:56 -0400

You can specify units= to be extra sure:

d <- difftime(Sys.Date() + 1, Sys.Date(), units = "mins") as.numeric(d, units = "days")

On Wed, Jun 25, 2008 at 12:23 AM, Richard M. Heiberger <rmh_at_temple.edu> wrote:
> I received a warning about incompatible methods that I don't understand.
> The workaround in this example is simple.
>
> What is the reason that these methods are seen as incompatible?
> Is there some dangerous consequence of my as.numeric() workaround?
> Can a fix to the code base, perhaps similar to my workaround, make this
> warning no longer necessary?
>
> I am using R 2.7.0 on Windows.
> version.string R version 2.7.0 (2008-04-22)
>
> Thanks
>
> Rich
>
>
>
> xlim <- as.Date(c("2005-04-09", "2007-09-07"))
> dx <- diff(xlim)
> xlim + c(-.02, .02)*dx ## correct answer and warning message
> xlim + as.numeric(c(-.02, .02)*dx) ## correct answer
>
>> xlim <- as.Date(c("2005-04-09", "2007-09-07"))
>> xlim
> [1] "2005-04-09" "2007-09-07"
>> dx <- diff(xlim)
>> dx
> Time difference of 881 days
>> xlim + c(-.02, .02)*dx ## correct answer and warning message
> [1] "2005-03-22" "2007-09-24"
> Warning message:
> Incompatible methods ("+.Date", "Ops.difftime") for "+"
>> xlim + as.numeric(c(-.02, .02)*dx) ## correct answer
> [1] "2005-03-22" "2007-09-24"
>>
>
> ______________________________________________
> R-help_at_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_at_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. Received on Wed 25 Jun 2008 - 05:07:09 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Wed 25 Jun 2008 - 05:31:30 GMT.

Mailing list information is available at https://stat.ethz.ch/mailman/listinfo/r-help. Please read the posting guide before posting to the list.

list of date sections of archive