Align Numeric Values from knitr command \Sexpr{} by Decimal in Table

Question

How can I align numeric values brought in from the knitr command \Sexpr{} by decimal in a table?

Just out of curiosity: Why wouldn't you use xtable or Hmisc to create the entire table in R?
Probably because of other bad habits. I need to include graphics and text as well as the R calculations in a table. I'm using knitr since my GRA position would otherwise have me copy and paste lots of output into a working document, piece-by-piece.

krlmlr · Accepted Answer · 2012-10-18 20:56:47Z

up vote 2 down vote accepted

Take a look at the dcolumn package. It allows defining a column that is centered at the decimal point. For example:

\begin{tabular}{D{.}{.}{3}}
    \Sexpr{1/4} \\
    \Sexpr{1/8} \\
\end{tabular}

Does this work for you? See the package's documentation for further options.

Add the \usepackage{dcolumn} command so that it appears in the preamble of the knitr-generated LaTeX file.

answered Oct 18 '12 at 20:56

krlmlr
2,9531031

	This is much simpler than hacking it up in the code chunk and recalling the individual pieces! – Chernoff Oct 18 '12 at 21:16
	This work well with numeric values, but not numeric values in math mode. – Chernoff Oct 18 '12 at 21:22
	@Chernoff: Might be due to "... that dcolumn always uses math mode for the digits as well as the separator." Does it work if you surround the `\Sexpr`s by `$` characters, to cancel the math mode that is created by `\Sexpr`? (See mail-archive.com/lyx-users@lists.lyx.org/msg27407.html for using a similar trick in a similar context but an entirely different environment.) – krlmlr Oct 18 '12 at 21:27
	Values from `\Sexpr` line as expected in the table, but fail to do so when bracketed by `$`s. – Chernoff Oct 18 '12 at 21:36
	@Chernoff: Then I don't understand your comment "This work well with numeric values, but not numeric values in math mode." Could you provide an example? – krlmlr Oct 18 '12 at 21:38

1 Answer