Hey!

I am currently trying to understand what the default “initval” strategy is. In the `pymc.model`

class it seems `None`

is stored in `self.rvs_to_initial_values`

for each RV that was not passed a `initval`

.

I know, that the NUTS initialization can place a jitter on the initval depending on the `init`

method here. But prior to that? Is it always the mean or the mode or a sample of the prior?

Thank you in advance!

Cheers!

By default it’s a `moment`

(usually the mean, but could be anything that has a finite logp).

It should work the same if you specified `initival="moment"`

. The only other option besides a user constant is `initval="prior"`

which takes a random draw from the prior.

You can see what it looks like by calling `model.initial_point()`

Jittering is applied over this initial point.

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Thanks for the quick answer. By “usually” you mean it depends on the distribution at hand?

I understand. Thank you !