R Sweave: digits number in xtable of prop.table

Question

I'm making an xtableFtable on R Sweave and can't find a way to suppress the digits with this code. What I am doing false? I've read that it can happen if your values aren't numeric but factor or character, but is prop.table making them non-numeric? I'm lost...

library(xtable)
a <- ftable(prop.table(table(mtcars$mpg, mtcars$hp), margin=2)*100)
b <- xtableFtable(a, method = "compact", digits = 0)
print.xtableFtable(b, rotate.colnames = TRUE)

I've already tried with digits=c(0,0,0,0...) too.

Answer 1

You could use options(digits) to control how many digits will print. Try something like options(digits = 4) as the first line of your code (change 4 to whatever value you want between 1 and 22 ). See ?options for more information.

Or round the values before printing

a = round(ftable(prop.table(table(mtcars$mpg, mtcars$hp), margin=2)*100), 2)
b = xtableFtable(a, method = "compact")
print.xtableFtable(b, rotate.colnames = TRUE)

Answer 2

The "digits" argument to xtableFtable seems to be unimplemented (as of my version, which is 1.8.3), since after playing around with it for half an hour nothing seems to make any difference.

There's a hint to this effect in the function documentation:

It is not recommended that users change the values of align , digits or align . First of all, alternative values have not been tested. Secondly, it is most likely that to determine appropriate values for these arguments, users will have to investigate the code for xtableFtable and/or print.xtableFtable .

It's probably just carried over from the xtable function (on which xtableFtable is surely based) as a TODO which the maintainer hasn't gotten around to yet.