Hi everyone,
I was wondering if it’s a good idea to initialize NUTS/HMC to a decent position in the parameter space?
For instance, in a set of ODEs I can run MCMC as a regression per equation (very quickly, seconds) before I run it for the entire system (very slow, many hours). I could initialize the latter using the median posterior parameter values found by the former (using init_to_values()).
I /was wondering if I can reduce the warmup phase, for instance from 1000 to 500 or even fewer samples, if I initialize with a good guess like that?