Hello, thank you for your answer.
You are right, this is probably exactly what I want.
Could you maybe guide me with implementing the bivariate normal, as I don’t find it to be easy :D.
As I mentioned previously, right now, I have two independent Poisson.
\theta_1 = exp(N_1 * data_1 + N_2 * data_2)
\theta_2 = exp(N_3 * data_3 + N_4 * data_4)
Is it possible to use the results of the \theta 's as the mu of the bivariate normal(with or without the exp), because I don’t seem to be able to do so. And how to choose the parameter chol?
Thank you very much for your help 