In the Inference with Discrete Latent Variables tutorial (Inference with Discrete Latent Variables — Pyro Tutorials 1.8.6 documentation), the explanation says “there is no way to linearly order x and y such that one’s plate nesting is less than the other”.
What does that mean exactly? I tried the code within the invalid_model and it didn’t throw an error, does it mean the error will only occur if we try to use TraceEnum_ELBO? Would the invalid_model be okay if we stick with Trace_ELBO (on that note, how bad is Trace_ELBO for discrete variables, is the difference only on computational efficiency)?
plate_1 = pyro.plate("plate_1", 10, dim=-1) # vectorized plate_2 = pyro.plate("plate_2", 10, dim=-2) # vectorized with plate_1: x = pyro.sample("x", Bernoulli(0.5)) with plate_2: y = pyro.sample("y", Bernoulli(0.5)) with plate_1, plate_2: z = pyro.sample("z", Bernoulli((1. + x + y) / 4.))
I’m quite confused. Thank you very much for reading this! (And is there a tutorial that explains the difference between vectorized plate and sequential plate?)