r - How to get dimnames in xtable.table output?

Question

I'd like to have the dimensions labeled in my xtable output. However, the table method of xtable does not output dimension labels even when I specify them manually to table:

set.seed(10)
d <- data.frame(x=sample(1:4),y=sample(1:4))
tb <- with(d, table(d,dnn=c("Xs","Ys")))
> tb
   Ys
Xs  1 2 3 4
  1 0 0 0 1
  2 0 1 0 0
  3 1 0 0 0
  4 0 0 1 0
> xtable(tb)
% latex table generated in R 2.15.1 by xtable 1.7-0 package
% Tue Oct  9 09:06:10 2012
egin{table}[ht]
egin{center}
egin{tabular}{rrrrr}
  hline
 & 1 & 2 & 3 & 4 \ 
  hline
1 &   0 &   0 &   0 &   1 \ 
  2 &   0 &   1 &   0 &   0 \ 
  3 &   1 &   0 &   0 &   0 \ 
  4 &   0 &   0 &   1 &   0 \ 
   hline
end{tabular}
end{center}
end{table}

Inspection of the code for xtable.table doesn't yield any secrets. Short of building them manually with multirow is there any way of getting the dimensions labeled?

Answer 1

This doesn't create multirow or multicolumn headers based on the names of the dimensions, but it at least does get them displayed.

print(xtable(format(ftable(tb))), 
      include.rownames=FALSE, include.colnames=FALSE,
      sanitize.text.function = function(x) {gsub('"',"",x)})

which gives

% latex table generated in R 2.15.1 by xtable 1.7-0 package
% Tue Oct 09 11:28:33 2012
egin{table}[ht]
egin{center}
egin{tabular}{llllll}
  hline
  hline
     & Ys & 1 & 2 & 3 & 4 \ 
  Xs &      &     &     &     &     \ 
  1  &      &   0 &   0 &   0 &   1 \ 
  2  &      &   0 &   1 &   0 &   0 \ 
  3  &      &   1 &   0 &   0 &   0 \ 
  4  &      &   0 &   0 &   1 &   0 \ 
   hline
end{tabular}
end{center}
end{table}

You can restore the horizontal lines in the "right" place as well:

print(xtable(format(ftable(tb))), 
      include.rownames=FALSE, include.colnames=FALSE,
      sanitize.text.function = function(x) {gsub('"',"",x)},
      hline.after = c(-1, 2, nrow(tb)+2))

giving

% latex table generated in R 2.15.1 by xtable 1.7-0 package
% Tue Oct 09 11:29:21 2012
egin{table}[ht]
egin{center}
egin{tabular}{llllll}
  hline
      & Ys & 1 & 2 & 3 & 4 \ 
  Xs &      &     &     &     &     \ 
   hline
1  &      &   0 &   0 &   0 &   1 \ 
  2  &      &   0 &   1 &   0 &   0 \ 
  3  &      &   1 &   0 &   0 &   0 \ 
  4  &      &   0 &   0 &   1 &   0 \ 
   hline
end{tabular}
end{center}
end{table}