[ADMB Users] hybrid mcmc

[dave fournier]

I wish you guys would fix up the site so that visitors would immediately
see various topics and could peruse them.

For example on the bugs list thee is a posting

https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=ind0911&L=BUGS&T=0&F=&S=&X=495A1A4505900009E4&Y=otter%40otter-rsch.com&P=748

I had forgotten about hybrid mcmc. I put that in admb for testing quite
a while back.
It works really well on this example I think.
It uses the gradient of the LL  to integrate a differential equation. 
This produces really good mixing, but for most packages
getting the gradient for a 1000 parameter model is  too computationally
costly.

If someone wants to run the bugs version of this model so we can verify
that the results are bad this would make a really good example.

Then we need a place on this site to display stuff like that so that
people can find it easily.