# Summary Function that is compatible with xtable

If you like to make nice looking documents using Latex, I highly recommend using the 'xtable' package. In most instances, it works quite well for producing a reasonable looking table from an R object. I however recently wanted a LaTeX table from the 'summary' function in base R. So naturally I tried:

library(xtable)
set.seed(123)
foo = rnorm(10)
summary(foo)
xtable(summary(foo))

Which gave me the following error:

Error in xtable.table(summary(foo)) :
xtable.table is not implemented for tables of > 2 dimensions

So I decided to create a simple function that would return a dataframe which is easy to use with xtable. Here is what I came up with.

summaryfunction= function (x){
if( is.numeric(x)!=TRUE) {stop("Supplied X is not numeric")}
mysummary = data.frame(
"Min." =as.numeric( min(x)),
"1st Qu." = quantile(x)[2],
"Median" = median(x),
"Mean" = mean(x),
"3rd Qu." = quantile(x)[4],
"Max." = max(x),
row.names=""

)
names(mysummary) = c("Min.","1st Qu.","Median","Mean","3rd Qu.","Max.")
return( mysummary )
}


Now, when I try to use xtable I get the following output:

% latex table generated in R 3.1.1 by xtable 1.7-4 package
% Tue Nov 04 21:58:07 2014
\begin{table}[ht]
\centering
\begin{tabular}{rrrrrrr}
\hline
& Min. & 1st Qu. & Median & Mean & 3rd Qu. & Max. \\
\hline
& -1.27 & -0.53 & -0.08 & 0.07 & 0.38 & 1.72 \\
\hline
\end{tabular}
\end{table}

This should lead to an easier way to incorporate more summaries when you are writing your paper, using R and Knitr of course. If you do use knitr, make sure to try the results = 'asis' option with xtable from R.