R/fv.annuity.R

In FinCal: Time Value of Money, Time Series Analysis and Computational Finance

#' Estimate future value of an annuity
#'
#' @param r discount rate, or the interest rate at which the amount will be compounded each period
#' @param n number of periods
#' @param pmt payment per period
#' @param type payments occur at the end of each period (type=0); payments occur at the beginning of each period (type=1)
#' @seealso \code{\link{fv}}
#' @export
#' @examples
#' fv.annuity(0.03,12,-1000)
#'
#' fv.annuity(r=0.03,n=12,pmt=-1000,type=1)
fv.annuity <- function(r,n,pmt,type=0) {
  if(type != 0 && type !=1){
    print("Error: type should be 0 or 1!")
  }else{
  fv = (pmt / r * ((1 + r)^n - 1))*(1+r)^type * (-1)
  return(fv)
  }
}