When I sample the posterior of my rather complex model (via NUTS), I see a strange behavior. Typically one chain will sample quite slowly, and the other 3 will sample quickly, at the speed I have come to expect. [image] Why is this occurring? Is the slow chain stuck in a place with difficult geom…

Every model is different, so it’s hard to give general advice. Since there’s differences across chains, it could be that one chain is being initialized in a region of parameter space that’s problematic for some reason. That can be remedied by using more informative priors, to rule out “bad” (“anti-p…

Why is sampling sometimes slow?

Questions v5

bridgeland August 21, 2025, 10:25am 4

Thanks. Will start by re-examining prior predictives.

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Why is sampling sometimes slow?

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