Add x offset to poisson mixture model?

Questions
5

Okay, I think I understand. I changed my code to the following:

with pm.Model() as model:
    lam1 = pm.Exponential('lam1', lam=1.)
    offset1 = pm.Categorical('offset1',p=[0.1 for x in range(max(new_stop_pos))])
    lam2 = pm.Exponential('lam2', lam=1.)
    offset2 = pm.Categorical('offset2',p=[0.1 for x in range(max(new_stop_pos))])
    pois1 = pm.Poisson.dist(mu=lam1+offset1)
    pois2 = pm.Poisson.dist(mu=lam2+offset2)
    w = pm.Dirichlet('w',a=np.array([1.,1.]))
    like = pm.Mixture('like',w=w,comp_dists=[pois1,pois2],observed=new_stop_pos)
with model:
    trace = pm.sample(50000,n_init=10000,tune=100000)

I’m still not seeing convergence though. The new traceplot looks like this:

Figure_1
Figure_1.png1200×1000 159 KB

Should I be doing something different in order to get better convergence?