[R] more or less pager

[Dirk Eddelbuettel]

On Fri, Feb 06, 2004 at 04:07:18PM +0100, David A. van Leeuwen wrote:
> R-users,
> 
> (forgive my return adres)
> 
> I've been breaking my head why R---which i find fabulous, by the 
> way---does not pipe interactive output through a pager (more or less), 
> like it does with help(), or like GNU Octave does with arrays with more 
> than terminal height rows. 
> 
> Maybe it is my installation (Debian/GNU Linux).  Maybe it is my 
> configuration, but i don't think so because with help() it works
> 
> ## Default pager
> PAGER=${PAGER-'/usr/bin/less'}

[ Future Debian R packages will have this default to PAGER-'/usr/bin/pager'
  which is handled by the dpkg-alternatives mechanism; this helps e.g. users
  in the Far East who use jless or jv; and everybody else who may prefer
  most or one of the other pagers. This follows a wishlist request I had
  for octave2.1, and which also makes sense for R. 
  
  Can't help you with the more R-internal request of paging wider than 80col,
  other than with the default answer to just about every UI question: use ESS
  as you then get the benefit if (x)emacs buffers around your session. Plus 
  much much more. It is really worth it, and on Debian only the few
  keystrokes of 'apt-get install ess' away. ]
  
> But i think it really is because R-users apparently don't look at 
> dataframes with more than, say, 24 rows.  I always seem to be intetrested
> in column names with some rows of data, so often I type
> 
> > data[1,]
> 
> just to see what the columns were called again.
> 
> In order to circumvent the problem of data running off the screen, I've 
> made a simple hack:
> 
> more <- function(x) {
>  tmp <- paste("/tmp/R", floor(runif(1,0,1e6)), sep=".")
>  sink(tmp)
>  print(x)
>  sink()
>  file.show(tmp, delete.file=TRUE)
> }
> 
> which isn't the prettiest implementation of `tmpfile', but hey, it 
> allows my to type
> 
> > more(data)

Not bad. But then again, there is ESS :)

Dirk

> 
> Please ignore this if there is a more proper way of doing this in R 
> (preferrably by default without the more()), but also please include 
> some reference to this under keywords `pager', `more' or `less' in the 
> documentation.
> 
> Developers, thanks for all the work.
> 
> -- 
> David A. van Leeuwen			< @ElseWare.nl>
> 
> 	  Echt stijlvol sterven doe je / bij een ander op de mat
> 	  Op de dag dat je bezorgd wordt / door het NRC Handelsblad
> 	
> 							---Joop Visser
> 
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