You have 4 random variables that satisfy 2 linear constraints, so you are trying to generate a point in a (4-2) = 2 dimensional linear (affine, in fact) subspace of R^4.
If you don't have any further requirement for the distribution of the random points you want to generate, there are infinitely many ways of doing it. It would be a good idea if you could explain in some more detail what you want to do, so that we can give you relevant suggestions. Best, Giovanni > Date: Wed, 26 Mar 2008 11:28:28 -0700 > From: "Ala' Jaouni" <[EMAIL PROTECTED]> > Sender: [EMAIL PROTECTED] > Precedence: list > > I am trying to generate a set of random numbers that fulfill the > following constraints: > > X1 + X2 + X3 + X4 = 1 > > aX1 + bX2 + cX3 + dX4 = n > > where a, b, c, d, and n are known. > > Any function to do this? > > Thanks, > -Ala' > > ______________________________________________ > R-help@r-project.org mailing list > 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. > > -- Giovanni Petris <GPetris @ uark.edu> Department of Mathematical Sciences University of Arkansas - Fayetteville, AR 72701 Ph: (479) 575-6324, 575-8630 (fax) http://definetti.uark.edu/~gpetris/ ______________________________________________ R-help@r-project.org mailing list 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.