Example for using plyr to replace strings in multiple columns

plyr_colwise_gsub.R

## Need plyr
require(plyr)

## Some fake data
foo <- data.frame(a=rep("foo", 3), b=rep("foofoo", 3), c=rep("foobarfoo", 3))

## Replace function, works on vectors
fn <- function(x) gsub("foo", "bar", x)

## Turn it into a column-wise function; only apply to cols "a" and "b"
fncol <- colwise(fn, .cols=c("a", "b"))

## Apply the function
fncol(foo)