Thank you for your help.
I am confused. The trace of the MH sampling of my model has four stats.
Each of those stats has the same shape: (10000, 6). I interpret that shape to be a row for each sample, and a column for each random variable.
accept seems to be the acceptance probability, and accepted seems to be whether the newly proposed value is actually accepted. At least it is the case that the True values for accepted are associated with larger values for accept.
But which column is associated with which random variable? They appear not to be in the same order as the RVs are defined in the model. At least the second RV in the model rarely takes a new value:
But the second column of accepted has quite a few new values.
The second from last column of accepted may the same as the second variable, as that column has only 53 new values, and eyeballing the above graph, there may be 53 changes in the line. If true, that would suggest that the order of the columns is the reverse of the order of RV definition.
But there must be a simpler way of determining which column of the stats is associated with which RV, a simpler way than eyeball comparison of the traceplot graphs to the accepted data.
Or maybe I am misunderstanding something, and jumping to conclusions about the MH stats.