try this~
data_format <- function(data,digit=2,type='%'){
if(type=='d') {
type = 'f';
digit = 0;
}
switch(type,
'%' = {format <- paste("%.", digit, "f%", type, sep='');num <- 100},
'f' = {format <- paste("%.", digit, type, sep='');num <- 1},
cat(type, "is not a recognized type\n")
)
sprintf(format, num * data)
}