R help - May 2009 - Sweave \Sexpr{} advice please

Dear List,

First off, my deepest gratitude to the Sweave developers: this tool has
improved my quality greatly.

A question in my work I use \Sexpr{} statements scalar values and the xtable
package for all manner of tables.  What I'd like to do is to use a vector
inline, rather than a whole separate table.   Something like:

%%%%%%%%%%%%%%%% begin code
% Latex junk

% Sweave block:
<<>>covmat <- cov(matrix(runif(100),ncol=3))
@

% back to Latex, typing up a report, my homework, etc.
The first column of the covariance matrix is $(\Sexpr{covmat[1,1]},
\Sexpr{covmat[2,1]}, \Sexpr{covmat[3,1]})^T$

%%%%%%%%%%%%%%%%% end code

but, of course, this is poor way of going about it.  Any suggestions?

Thanks in advance.

Regards,

Kyle

	[[alternative HTML version deleted]]

Kyle Matoba <kmmatoba <at> ucdavis.edu> writes:
> A question in my work I use \Sexpr{} statements scalar values and the
xtable
> package for all manner of tables.  What I'd like to do is to use a
vector
> inline, rather than a whole separate table.   Something like:
> 
> % Sweave block:
> <<>>> covmat <- cov(matrix(runif(100),ncol=3))
> @
> 
> % back to Latex, typing up a report, my homework, etc.
> The first column of the covariance matrix is $(\Sexpr{covmat[1,1]},
> \Sexpr{covmat[2,1]}, \Sexpr{covmat[3,1]})^T$
> 
To unclutter the text in Sexpr, I normally prepare the results in the 
Sweave block in advance

Dieter

covmat <- cov(matrix(runif(30),ncol=3))
ft = paste(round(covmat[,3]),collapse=", ")
ft
named = c(Val=3,StdDev=4,p=0.4)
ft = paste(names(named),named,sep="= ",collapse=", ")
ft

Hi Kyle,
> First off, my deepest gratitude to the Sweave developers: this tool has
> improved my quality greatly.
> 
> A question in my work I use \Sexpr{} statements scalar values and the
xtable
> package for all manner of tables.  What I'd like to do is to use a
vector
> inline, rather than a whole separate table.   Something like:
> 
> %%%%%%%%%%%%%%%% begin code
> % Latex junk
> 
> % Sweave block:
> <<>>> covmat <- cov(matrix(runif(100),ncol=3))
> @
> 
> % back to Latex, typing up a report, my homework, etc.
> The first column of the covariance matrix is $(\Sexpr{covmat[1,1]},
> \Sexpr{covmat[2,1]}, \Sexpr{covmat[3,1]})^T$
> 
> %%%%%%%%%%%%%%%%% end code
> 
> but, of course, this is poor way of going about it.  Any suggestions?
<<loadPkg, echo=FALSE>>   require(xtable)
@

<<>>covmat <- cov(matrix(runif(99), ncol=3)) # 99 not 100
@

The first row of the\dots is
<<firstRow, echo = FALSE, results=tex>>
xtable(covmat[1,,drop=FALSE])
@

This should get you started. Be sure to
explore the facilities of the xtable package
(you can use captions, labels etc.):

?xtable
?print.xtable

The results=tex option to the chunk is
important as well, of course.

HTH,
Tobias