R/pv.R

In RachelRamirez/NPS: Visualize the National Park Service and Benson Acoustic Summary Database

pv <- function(FV, r, n = 5) {
  
if(!is.atomic(FV)) {
  stop('FV must be an atomic vector')
}

if(!is.numeric(FV) | !is.numeric(r) | !is.numeric(n)) {
  stop('This function only works for numeric inputs!\n',
       'You have provided objects of the following classes:\n',
       'FV: ', class(FV), '\n',
       'r: ', class(r), '\n',
       'n: ', class(n))
}

if(r < 0 | r > .25) {
  message('The input for r exceeds the normal\n',
          'range for interest rates (0-25%)')
}

  present_value <- FV / (1 + r)^n
  round(present_value, 2)
}