Print R Matrices in LaTeX Math Environments

This is a quick and easy method to print R matrices in LaTeX math environments. It’s based on the R function found here. (The newline at the end of the bmatrix should be removed)

Use this function

bmatrix = function(x, digits=NULL, ...) {
  library(xtable)
  default_args = list(include.colnames=FALSE, only.contents=TRUE,
                      include.rownames=FALSE, hline.after=NULL, comment=FALSE,
                      print.results=FALSE)
  passed_args = list(...)
  calling_args = c(list(x=xtable(x, digits=digits)),
                   c(passed_args,
                     default_args[setdiff(names(default_args), names(passed_args))]))
  return(cat("\\begin{bmatrix}\n",
      do.call(print.xtable, calling_args),
      "\\end{bmatrix}"))
}

And then insert the matrix as seen here

\begin{equation}
a =
<<results = 'asis', echo=FALSE>>=
bmatrix(a)
@
\end{equation}

Grab the .Rnw example file here. It should compile into something like this