[R] Determine the data type of a function to an argument

[Alex Restrepo]

Hello All:

How can I determing the "types" of args passed to an R function?  For 
example, given the following:


    calculate <- function(...)
    {
        args <- list(...)
        argName     = names(args)

        if (arg1 == character)
            cat("arg1 is a character")
        else
             cat("arg1 is numeric")


        if (arg2 == character)
            cat("arg2 is a character")
        else
            cat("arg2 is a numeric")

    }
    value = calculate(arg1='222' arg2=333)

Programatically, how can I determine if arg1 is a character and arg2 is 
numeric?

Many Thanks:

Alex