R help - Apr 2005 - xtable POSIXt

Hi,

I was trying like to print out data frame with POSIXct column
in html format using xtable package, but I got error message
when trying to print the table. Here is example:

  aaa<-data.frame(as.POSIXct(strptime('03 2005', '%d %Y')),0)
  aaa.tab<-xtable(aaa)
  print(aaa.tab)

  Error in Math.POSIXt(x + ifelse(x == 0, 1, 0)) :
          abs not defined for POSIXt objects

I was able to get around the problem with converting column 
back to string but still I would like to know is it a bug or 
I was doing something wrong. 

thanks,

-- 
Miha Razinger
Environmental Agency of Slovenia
Office of Meteorology

On Thu, 14 Apr 2005, Miha Razinger wrote:
> Hi,
>
> I was trying like to print out data frame with POSIXct column
> in html format using xtable package, but I got error message
> when trying to print the table. Here is example:
>
>  aaa<-data.frame(as.POSIXct(strptime('03 2005', '%d
%Y')),0)
>  aaa.tab<-xtable(aaa)
>  print(aaa.tab)
>
>  Error in Math.POSIXt(x + ifelse(x == 0, 1, 0)) :
>          abs not defined for POSIXt objects
>
> I was able to get around the problem with converting column
> back to string but still I would like to know is it a bug or
> I was doing something wrong.
It's not a bug in R.

It seems to be a docmentation error or infelicity in xtable: it clearly 
does not work with all data frames, and the restrictions are neither clear 
to me nor enforced.  Please take it up with the xtable maintainer.


-- 
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