Hi, thanks for the reply. A will be a given matrix satisfying condition 1. I want to find the vector w that minimizes the quadratic form. w satisfies condition 2.
2010/4/10 Paul Smith <phh...@gmail.com> > On Sat, Apr 10, 2010 at 5:13 PM, Paul Smith <phh...@gmail.com> wrote: > >> I am trying to minimize the quardratic form w'Aw, with certain > >> constraints. > >> In particular, > >> (1) A=(a_{ij}) is n by n matrix and it is symmetric positive > definite, > >> a_{ii}=1 for all i; > >> and 0<a_{ij}<1 for i not equal j. > >> (2) w'1=n; > >> (3) w_{i}>=0 > >> > >> Analytically, for n=2, it is easy to come up with a result. For larger > n, it > >> seems > >> difficult to obtain the result. > >> > >> Does any one know whether it is possible to use R to numerically compute > it? > > > > And your decision variables are? Both w[i] and a[i,j] ? > > In addition, what do you mean by "larger n"? n = 20 is already large > (in your sense)? > > Paul > > ______________________________________________ > 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<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 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.