R devel - Oct 2008 - cut.Date problem when starting on first day of week (PR#13159)

Apparently any (?) call of the form

cut(date,"weeks")

where the date *begins the week*, gives the error

Error in 1:(1 + max(which(breaks < maxx))) :
  result would be too long a vector
In addition: Warning message:
In max(which(breaks < maxx)) :
  no non-missing arguments to max; returning -Inf

 To my surprise, this was first reported as a problem in 2006 (!)
(version 2.3.1 (!)), by Mikkel Grum:

http://finzi.psych.upenn.edu/R/Rhelp02a/archive/83122.html (17 Aug 2006)
https://stat.ethz.ch/pipermail/r-devel/2008-September/050710.html
https://stat.ethz.ch/pipermail/r-devel/2008-October/050914.html

  In particular, try:

d <-
seq.Date(as.Date("2008-07-05"),as.Date("2008-07-08"),by="days")
weekdays(d)

cut(d[1],"weeks") ## OK
cut(d[2],"weeks") ## OK
cut(d[3],"weeks") ## Monday -- breaks
cut(d[4],"weeks") ## OK

cut(d[1],"weeks",start.on.monday=FALSE) ## OK
cut(d[2],"weeks",start.on.monday=FALSE) ## Sunday -- breaks
cut(d[3],"weeks",start.on.monday=FALSE) ## OK
cut(d[4],"weeks",start.on.monday=FALSE) ## OK

  The particular line that fails within cut.Date is

breaks <- breaks[1:(1 + max(which(breaks < maxx)))]

  but I haven't figured out enough about what's going on
to be able to suggest a fix ...

  cheers
    Ben Bolker

It should be <= not < .

There is a similar problem with POSIXct (but only for times at midnight).

On Mon, 13 Oct 2008, bolker at zoology.ufl.edu wrote:
>    Apparently any (?) call of the form
>
> cut(date,"weeks")
>
> where the date *begins the week*, gives the error
>
> Error in 1:(1 + max(which(breaks < maxx))) :
>  result would be too long a vector
> In addition: Warning message:
> In max(which(breaks < maxx)) :
>  no non-missing arguments to max; returning -Inf
>
> To my surprise, this was first reported as a problem in 2006 (!)
> (version 2.3.1 (!)), by Mikkel Grum:
>
> http://finzi.psych.upenn.edu/R/Rhelp02a/archive/83122.html (17 Aug 2006)
> https://stat.ethz.ch/pipermail/r-devel/2008-September/050710.html
> https://stat.ethz.ch/pipermail/r-devel/2008-October/050914.html
>
>  In particular, try:
>
> d <-
seq.Date(as.Date("2008-07-05"),as.Date("2008-07-08"),by="days")
> weekdays(d)
>
> cut(d[1],"weeks") ## OK
> cut(d[2],"weeks") ## OK
> cut(d[3],"weeks") ## Monday -- breaks
> cut(d[4],"weeks") ## OK
>
> cut(d[1],"weeks",start.on.monday=FALSE) ## OK
> cut(d[2],"weeks",start.on.monday=FALSE) ## Sunday -- breaks
> cut(d[3],"weeks",start.on.monday=FALSE) ## OK
> cut(d[4],"weeks",start.on.monday=FALSE) ## OK
>
>  The particular line that fails within cut.Date is
>
> breaks <- breaks[1:(1 + max(which(breaks < maxx)))]
>
>  but I haven't figured out enough about what's going on
> to be able to suggest a fix ...
>
>  cheers
>    Ben Bolker
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel
>
-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
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