Noncentral Beta Distribution

Compute the Noncentral Beta using Transformations

This function computes the probability density function for the
noncentral beta distribution using a transformation of variables to put
the desired density function in terms of a noncentral F, which is included
in Matlabs statsitics toolbox already.
USAGES
[ pz ] = ncbeta (x, a, b, lambda )

%To test with a histogram that gives the ratio of to IID chi-square RVs, compute:

y(1:50)=-sqrt(10);y(51:100)=+sqrt(10);

znum = ncx2rnd(ones(5e4,1), y'*y);

z = znum./(znum +
ncx2rnd(99*ones(5e4,1), 0));

[N,b] = hist(z,floor(sqrt(length(z))));
N=N./trapz(b,N);
bar(b, N,'facecolor','k')
hold on
plot(r, ncbeta (r, 1, 99, y'*y),'linewidth',4,'r');