a demostration of using catcolwise -- a function that creates a function.

catcol.R

## make a fake data frame
test <- data.frame(foo=gl(n=3,k=2,labels=c("low","med","high")),bar=rep(letters[1:2],3),zoop=runif(6))

## these are all factors
str(test)

## I want them to be characters, not factors, but I am too lazy to run as.character on every categorical factor

library(plyr)
test_char <- catcolwise(as.character)(test)

# success!
str(test_char)

## OR

test2 <- data.frame(apply(test, 2, as.character))

str(test2)