Thanks, I got some clarity. Each chain is the value of mu for each data point. When I do np.shape(pm.trace_to_dataframe(trace_N)) I get (2000, 13) so there are 2000 samples. So there are 2000 chains?
The old version of traceplot plots a trace for each chain . That is why you see two lines instead of one in the plots that correspond to
alpha,betaandsigma.
I dont quite get this, shouldnt there be 2000 lines then?
When the trace had non scalar RVs (like
mu), the old behavior of traceplot was to draw one like for each element in the RV (mu[0],mu[1], etc) and also draw separate traces for each chain.
Again shouldnt there be 2000 then? The last plot above has around 20.
Also np.shape(trace_N) is (1000, 1) but np.shape(pm.trace_to_dataframe(trace_N)) is (2000, 13). If I did trace_N = pm.sample(1000, tune=1000) i.e sample 1000, why is the dimension 2000?