Thanks again for your help, One digit after the decimal point is enough for my purposes; so, I can round the qexp function, even if possible errors in floating points are not a problem. Thank you very very much,
Denis Il giorno mer 27 gen 2021 alle ore 20:48 Abby Spurdle <spurdl...@gmail.com> ha scritto: > I note that there's a possibility of floating point errors. > If all values have one digit after the decimal point, you could replace: > qexp (p, rate) with round (qexp (p, rate), 1). > > However, sometimes uniroot will fail, due to problems with input. > > On Thu, Jan 28, 2021 at 5:02 AM Denis Francisci > <denis.franci...@gmail.com> wrote: > > > > Wonderful! > > This is exactly what I need! > > Thank you very much!! > > > > Denis > > > > > > > > Il giorno mer 27 gen 2021 alle ore 10:58 Abby Spurdle < > spurdl...@gmail.com> ha scritto: > >> > >> u <- runif (410) > >> u <- (u - min (u) ) / diff (range (u) ) > >> > >> constrained.sample <- function (rate) > >> { plim <- pexp (c (9.6, 11.6), rate) > >> p <- plim [1] + diff (plim) * u > >> qexp (p, rate) > >> } > >> > >> diff.sum <- function (rate) > >> sum (constrained.sample (rate) ) - 4200 > >> > >> rate <- uniroot (diff.sum, c (1, 2) )$root > >> q <- constrained.sample (rate) > >> > >> length (q) > >> range (q) > >> sum (q) > >> > >> > >> On Wed, Jan 27, 2021 at 9:03 PM Denis Francisci > >> <denis.franci...@gmail.com> wrote: > >> > > >> > Hi, > >> > I would like to generate random numbers in R with some constraints: > >> > - my vector of numbers must contain 410 values; > >> > - min value must be 9.6 and max value must be 11.6; > >> > - sum of vector's values must be 4200. > >> > Is there a way to do this in R? > >> > And is it possible to generate this series in such a way that it > follows a > >> > specific distribution form (for example exponential)? > >> > Thank you in advance, > >> > > >> > D. > >> > > >> > [[alternative HTML version deleted]] > >> > > >> > ______________________________________________ > >> > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > >> > https://stat.ethz.ch/mailman/listinfo/r-help > >> > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > >> > and provide commented, minimal, self-contained, reproducible code. > [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.