i2pi

interest <- function (balance, r)
{
    cash_flow <- c(0,diff(c(0,balance)))
    for (i in 2:length(cash_flow))
        cash_flow[i] <- (cash_flow[i] + cash_flow[i-1]) * (1 + r)
    cash_flow[2:(length(balance)+1)] - balance
}

gen_nsweep <- function (N, days=31)
{