I want to put a comment under a table printed out by xtable. I figured that the best option would be to use the "caption" option: xtable(tablename, caption="This is a caption"). But this is somehow putting in a "Table 1" automatically, so that the output looks like:
Table 1: This is a caption.
Is there any way to suppress this or any simpler way of putting in a comment simply as an additional last row in the table?
Answer
First, some mock data:
x <- sample(LETTERS, 5, replace = TRUE)
y <- sample(LETTERS, 5, replace = TRUE)
z <- table(x, y)
Now here's a somewhat clumsy solution, using print.xtable's add.to.row argument.
comment <- list()
comment$pos <- list()
comment$pos[[1]] <- c(nrow(z))
comment$command <- c(paste("\\hline \n", # we`ll replace all default hlines with this and the ones below
"your footnote, caption or whatever. \n",
sep = ""))
print(xtable(z),
add.to.row = comment,
hline.after = c(-1, 0)) # indicates rows that will contain hlines (the last one was defined up there)
If you want your comment to be placed before the data, use comment$pos[[1]] <- c(0) instead of comment$pos[[1]] <- c(nrow(z)) and adjust hline.after accordingly.
Here's my output:
% latex table generated in R 2.14.1 by xtable 1.7-0 package
% Mon Feb 20 02:17:58 2012
\begin{table}[ht]
\begin{center}
\begin{tabular}{rrrrr}
\hline
& B & C & P & V \\
\hline
A & 0 & 0 & 0 & 1 \\
D & 1 & 0 & 0 & 0 \\
I & 0 & 0 & 0 & 1 \\
P & 0 & 0 & 1 & 0 \\
Z & 0 & 1 & 0 & 0 \\
\hline
your footnote, caption or whatever.
\end{tabular}
\end{center}
\end{table}