latex() etc.: How to nicely format a matrix for a LaTeX document?

Thanks, John, I did.

Here is an update [not all problems are solved; can they be?]:

Consider:

library(xtable)
mat <- matrix(c(1,NA,3,100,10012.23423,4), ncol = 3, byrow = TRUE)
print(xtable(mat, digits = 1), floating = FALSE, only.contents = TRUE,
? ? ?include.rownames = FALSE, include.colnames = FALSE, hline.after = NULL)

With this one obtains a clean output of the rows (maybe someone knows how to suppress the "% latex table generated..." that is displayed).
However, as you can see from the output, the "&" symbols are not vertically aligned (that would be quite helpful in reading the table in a source file). This is even worse if you have row names of different lengths...

So my questions (2) and (3) are solved, but (1) remains. Is there any way to (maybe) first format the matrix entries to get the right alignment in xtable()?

Cheers,

Marius

On 2010-12-30, at 21:29 , John Kane wrote:

Have a look at xtable.

--- On Thu, 12/30/10, Marius Hofert <m_hofert at web.de> wrote:

From: Marius Hofert <m_hofert at web.de>
Subject: [R] latex() etc.: How to nicely format a matrix for a LaTeX document?
To: "Help R" <r-help at stat.math.ethz.ch>
Received: Thursday, December 30, 2010, 11:50 AM
Dear (T)eXpeRts,

I try to create a LaTeX table from an R matrix for the
first time. I am not sure what the "best" approach is, I
just read about latex() from Hmisc (toLatex() didn't work).

Consider the following minimal example:

library(Hmisc)
mat <- matrix(c(1,NA,3,100,10000,4), ncol = 3, byrow =
TRUE)
latex(mat, file = "", booktabs = TRUE, numeric.dollar =
FALSE, table.env = FALSE)

I am only interested in the part between \midrule and
\bottomrule [I couldn't figure out how to remove the tabular
environment]. It looks like this:

? 1&&3\tabularnewline
100&10000&4\tabularnewline

My questions/problems are:

(1) if there are NA's, you can see that the output is not
aligned according to the &-symbols. That makes it hard
to read in a LaTeX *source* file. How can I get something
like:
? 1&
? ?&3\tabularnewline
100&10000&4\tabularnewline

(2) it would even be nicer to read if the output was like
this:
? 1 & ? ? ? & 3
\tabularnewline
100 & 10000 & 4 \tabularnewline
How can I achieve this?

(3) is there another package/function to get output like
this more easily? I wrote a one-liner which formats the
lines separately, but it would be nice to have the columns
aligned as given in (2). I believe it is most helpful to
have the output in a form which is readable in a *source*
file (i.e., .tex), since the headers/footers from tabular
[or tabularx etc.] are often easy to put in the document.

Cheers,

Marius