So far the NoDistribution model in ver 4 still isn’t working for me. And this is the error message I’ve been getting, something about the ‘dist_param’ of the attribute, Distribution.dist().
I’ve read similar issues about some other distribution models also having the same issue. Would love some insights to this.
Welcome!
Generally, pm.NoDistribution is only used to as a parent for new distribution classes. Using it directly in a model like this is atypical. Can you provide some context for what you are trying to do?
Hey thanks for replying. We are using the pm.NoDistribution as a filler model for a variable that doesn’t have a prior, but rather depends on other parameters and is sampled by a Gibbs sampler for a Tikhonov regularization model.
In the previous pymc3 version, this model was working just fine, however, after we’ve upgraded to pymc4, this model function is no longer working.
Can you use a pm.Flat or pm.DensityDist (and manually assign it to your gibbs sampler) for that?
NoDistribution is now indeed a kind of metaclass that is not going to work on it’s own.
Using the pm.Flat distribution gives me the following error message: “module ‘pymc.model’ has no attribute ‘FreeRV’.” following by the failure of the sampler chains.
Can you share the whole code/ error message? You are probably trying to use some old API that has changed.
FreeRV is no longer a thing in V4. All PyMC variables are now simple Aesara TensorVariables. You’ll have to update your custom step sampler logic.
