Using a vector's print method in a data frame

Question

Consider the following vector x

x <- c(6e+06, 75000400, 743450000, 340000, 4300000)

I wish to print x in milli

Answer 1

you need a format method and an as.data.frame method, like these:

x <- c(6e+06, 75000400, 743450000, 340000, 4300000)
class(x) <- 'million'
format.million <- function(x,...)paste0(round(unclass(x) / 1e6, 1), "M")
as.data.frame.million <- base:::as.data.frame.factor
data.frame(x)