You can use uniroot: npv <- function(i, cf, tt = seq(along = cf)) sum(cf / (1-i)^tt) npv0 <- npv(0.1, 1:10) npv0 f <- function(i, cf, npv0) npv0 - npv(i, cf) uniroot(f, c(0.01, .99), cf = 1:10, npv0 = npv0)
On 11/30/05, paul sorenson <[EMAIL PROTECTED]> wrote: > I am trying to replace a spreadsheet model of a project justification > with an R script. > > I can't seem to track down R functions to calculate Internal Rate of > Return and NPV? Am I missing something? NPV doesn't seem so difficult > to calculate (at least for a regular series) but I am struggling to > identify how to solve for IRR in R. > > It would be sufficient if it worked for a regular series but really > useful if there was something that worked with irregular time series. > > cheers > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
