You want random numbers within the n-dimensional simplex (sum xi <=1) The easiest solution of course would be creating n-dimensions vectors with iid uniform components on [0,1) and throwing away those violating the inequality. Since the volume of the n-dimensional simplex is 1/n! (factorial) this becomes very wasteful even for low dimensions.
A possible answer is to use the Dirichlet distribution from package lca) since the uniform distribution on the simplex is a special case of the Dirichlet distribution. > On Nov 27, 2014, at 14:57, Jue Lin-Ye <jl.i...@gmail.com> wrote: > > Hello! I am relatively new using R, but this is my contribution to the > answer. How about using a Monte-Carlo method. Generate m numbers in the > support [0,1], where m>n. Then constrain by constructing a loop that takes > every one of the elements in the m sized vector and select the ones that > sum up to one. If it is very uncommon to sum up to one, given the > distribution that you use to generate the random numbers, you can construct > a loop that generates as many random numbers as you need and then follow > the steps > 1.generate > 2.select > > until you find a total of n number. > >> Dear all, >> I use R 3.1.1 for Windows. >> kindly how can I generate n number of random numbers with probability > from [0,1] >> and their sum must not be more than one >> thanks in advance >> Ragia > > Best regards, > > -- > Jue Lin-Ye > > --------------------------------------------------------------- > Civil Engineering phD candidate > Maritime Engineering Laboratory (LIM) > Universitat Politècnica de Catalunya (UPC) > C/Jordi Girona 1-3, Barcelona 08034 (Spain) > ----------------------------------------------------------------- > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. ______________________________________________ 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.