Discount Future Values with Flexible Start Year

Applies standard discounting to future values starting from a specified year. Values before the start year remain unchanged.

Usage

discount_future_values(years, values, discount_rate, discount_start_year)

Arguments

years

Numeric vector of years/time periods

values

Numeric vector of values to discount (same length as years)

discount_rate

Numeric discount rate as decimal (e.g., 0.03 for 3 percent)

discount_start_year

Numeric year when discounting should begin

Value

Numeric vector of discounted values (same length as input)

Examples

years <- 2020:2025
costs <- c(1000, 1200, 1500, 1800, 2000, 2200)
discounted <- discount_future_values(years, costs, 0.03, 2023)