[R] Sweave: multiline Sexpr?

[David Huffer]

Duncan, it's the first example you provide that I'm looking to do.
These Sexpr quickly exceed 80 columns and I was wanting to make them
more readable in the latex code by blocking and indenting the R code.
Dieter suggests putting the R code into a code block then Sexpr-ing that
object.  That seems like the way to go, but it seems not to take full
advantage of the language.  Thank you both.  David 

-----Original Message-----
From: Duncan Murdoch [mailto:murdoch at stats.uwo.ca] 
Sent: Tuesday, June 30, 2009 1:16 PM
To: David Huffer
Cc: r-help at r-project.org
Subject: Re: [R] Sweave: multiline Sexpr?

On 30/06/2009 12:44 PM, David Huffer wrote:
> Is there any way to have Sexpr span multiple lines?

For input or output?  I.e. do you want

\Sexpr{x +
y}

or do you want the value to display on multiple lines?

I think you can't do the first.  To do the second, returning a character

value with an embedded newline should work.  For example,

<<echo=FALSE>>=
string <- "this goes on \\\\\\\\\n two lines"
@
\Sexpr{string}

(I think you really need all those escapes to get two backslashes in the

output!)

I don't know if it will happen for 2.10.x, but I would like to extend 
\Sexpr to be just as flexible as the <<>>= notation, by putting the 
Sweave options in a Latex-like option:

\Sexpr[fig=true]{ plot(rnorm(1000))}

You can do this now in R-devel in the new Sweave-like syntax in Rd files

(except they don't support figs yet), but not yet in the original.

Duncan Murdoch