Wishard random draws
[w]=wish_rnd(sigma,v)
* sigma = symmetric pds input matrix
* v = degrees of freedom parameter
* w = random wishart_n(sigma) distributed matrix
x = rand(100,5,'n'); xpx = x'*x; w = zeros(5,5); for i = 1:1000; w = +wish_rnd(xpx,10); end // Example taken from wish_d().