Could I ask one question which confuses me for a long long time, even though there have been already many similar questions on this forum?
When I start to find mode, (set mh_replic=0), sometimes no matter I use mode_compute=9, the result always shows"(minus) the hessian matrix at the “mode” is not positive definite!".
In this case, I will run mode_compute=6 to get a “nice” mode check plot. Then I use this mode file to run mode_compute=9 again, if hessian matrix is positive definite, then I run MCMC ,like 200000 draws with mode_compute=9;
If hessian matrix is still not positive definite, I just run MCMC with mode_compute=6 to get final results.( 9 is better than 6 to run MCMC if hessian matrix is positive definite)
Are these steps reasonable? or Could you give me some advice? By the way,is mode_compute=9 always better than 4 since the former one is globally finding mode, while the later one is locally.