R help - May 2003 - Re: dates in chron package, split warning message

>
> > Dear All,
> >
> > I am currently using R for windows.
> >
> > I am wondering why the dates command in chron package does not work in
the
> > following situation:
> >
> > cut(dates(c(23,45,67),origin=c(1,1,2004)),"months")
> >
> > but will work for:
> >
> > cut(dates(c(23,45,67),origin=c(1,1,2004)),"days")
> > cut(dates(c(23,45,67),origin=c(1,1,2004)),"weeks")
> >
> > My second query is rather trivial but I am wondering why warning
messages
> > were given when using the split in this manner:
> >
> > split(matrix(1:12,nrow=4),c(1,1,2,3)) # Which does what I want it to
do.
> >
> > and no warning messages were given in Splus6 for example?
> >
> >
> >
>
****************************************************************************
> > **********
> >
> >  Steve Su (s.su at qut.edu.au)
> >  PhD student.
> >
> >  School of Accountancy
> >  School of Mathematical Sciences
> >  Queensland University of Technology
> >
> >  Postal Address: Steve Su, School of Accountancy, QUT, PO Box 2434,
> > Brisbane,
> >  Queensland, Australia, 4000.
> >
> >
> >  Phone:  +61 7 3864 2017
> >  Fax:    +61 7 3864 1812
> >  Mobile: 0421  840  586
> >      .
> >    _--_|\
> >   /      QUT
> >   \_.--._/
> >         v
> >
> >
>
****************************************************************************
> > **********
> >
> >
>
****************************************************************************
> > **********
> >
> >  Steve Su (s.su at qut.edu.au)
> >  PhD student.
> >
> >  School of Accountancy
> >  School of Mathematical Sciences
> >  Queensland University of Technology
> >
> >  Postal Address: Steve Su, School of Accountancy, QUT, PO Box 2434,
> > Brisbane,
> >  Queensland, Australia, 4000.
> >
> >
> >  Phone:  +61 7 3864 2017
> >  Fax:    +61 7 3864 1812
> >  Mobile: 0421  840  586
> >      .
> >    _--_|\
> >   /      QUT
> >   \_.--._/
> >         v
> >
> >
>
****************************************************************************
> > **********
> >
>

On Thu, 22 May 2003, Steve Su wrote:
> > > I am currently using R for windows.
> > >
> > > I am wondering why the dates command in chron package does not
work in
> the
> > > following situation:
> > >
> > > cut(dates(c(23,45,67),origin=c(1,1,2004)),"months")
> > >
> > > but will work for:
> > >
> > > cut(dates(c(23,45,67),origin=c(1,1,2004)),"days")
> > > cut(dates(c(23,45,67),origin=c(1,1,2004)),"weeks")
The dates function (not command) does work of course.  It's cut.dates
which fails.  The short answer to you is this is a great opportunity to
learn to debug R functions, and the hint is that the line

    from <- switch(by, days = from, 
	weeks = (from - day.of.week(mdy$m,mdy$d, mdy$y) + as.numeric(start.on.monday)),
        months = chron(julian(mdy$m, 1, mdy$y, origin = orig)),
        years = chron(julian(1, 1,mdy$y, origin = orig)))

contains two bugs.
> > > My second query is rather trivial but I am wondering why warning
> messages
> > > were given when using the split in this manner:
> > >
> > > split(matrix(1:12,nrow=4),c(1,1,2,3)) # Which does what I want it
to do.
> > >
> > > and no warning messages were given in Splus6 for example?
Try reading the help pages in each system.  They do not define split in 
the same way, and your usage is incorrect in R but not in S-PLUS 6.1.

-- 
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)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595