R/net.future.value.R

In antoanne/ifmFramework: Financial evaluation of Projects

#' Net Future Value is a combination of different future values from different 
#' times, all which are put into one larger present value.
#' 
#' @name net.future.value
#' 
#' @aliases nfv
#' 
#' @description  Net Future Value is a combination of different future values 
#' from different times, all which are put into one larger present value.
#' 
#' @param cfs A vector with a series of cash flows.
#' @param interest.rate A number that represents the nominal Interest Rate, 
#' presented by year.
#' @param begin.of.period A boolean that represents if the Tax Rate will be 
#' applied at the begining of period. FALSE by default.
#' 
#' @return A future value of a cash flow series.
#' 
#' @export
#' 
#' @keywords futureValue
#' 
#' @family financial
#' 
#' @examples
#'
#' ex.nfv <- net.future.value(c(-350,100,200,150,75), 0.0619, TRUE)
#' 
net.future.value <-
function(cfs = c(-350,100,200,150,75), 
         interest.rate = 0.0619, 
         begin.of.period = TRUE) 
  {
    time.instance <- if(begin.of.period) {0:(length(cfs)-1)} else {1:(length(cfs))}
    tax.rate <- ((1 + (interest.rate)) ^ time.instance)
    return (sum(cfs * tax.rate))
  }