I am working on Parameter estimation. I've been told to use MCMC. I've chosen the Metropolis-Hasting algorithm. I think I understand the algorithm.
I have around 8 input parameters to estimate. How do I go about choosing a multivariate proposal distribution and acceptance ratio? what factors should be considered? Also, the values for parameters need to be varied only by +\- 50% of their default values, How can I specify this?
I have seen the code examples of MCMC in Python and R, I don't understand them that well, most of them are for 2-3 variables.
Any help is appreciated. It would also be sufficient if you could just explain me the intuition behind choosing the proposal distribution and the acceptance ratio function.