[R] How to quieten axis() for Sweave: avoid echoing NULL?

[Ulises M. Alvarez]

Hi!

The following works for me:

\begin{figure}
\centering
<<fig1.R,fig=true,echo=false>>=
plot(1:4, rnorm(4), axes=FALSE)
axis(1, 1:4, LETTERS[1:4])
@
\caption{Plot test}
\label{fig:1}
\end{figure}

I'm using R 2.0.1 on an i686 with GNU/Linux Ubuntu 4.10.

Andrew Robinson wrote:
> Dear R-community,
> 
> I'm using Sweave to produce reports.  The reports require the "axis"
> command.  When I run axis the program returns NULL as well as creating
> the axis.  
> 
> 
>>plot(1:4, rnorm(4), axes=FALSE)
>>axis(1, 1:4, LETTERS[1:4])
> 
> NULL
> 
> 
> So, my Sweave tex files have 
> 
> \begin{Schunk}
> \begin{Soutput}
> NULL
> \end{Soutput}
> \end{Schunk}
> 
> in front of each graphic that requires axis.  I can easily find them
> and remove them, but I was wondering: is it something I can avoid?  Or
> am I doing something foolish and obvious?
> 
> Thanks for any assistance,
> 
> Andrew
---
Ulises M. Alvarez
<umalvarez at fata.unam.mx>