Request to clarify functioning of Bound

Questions
1

Is a single Bound thing a thing that can be used once or does it define a class-like thing that can be used over and over. In the PyMC3 documents, we see this example:

with pm.Model() as model:
    BoundedNormal = pm.Bound(pm.Normal, lower=0.0)
    x = BoundedNormal('x', mu=1.0, sd=3.0)

But it’s not clear from the documentation, or from the examples if this BoundedNormal thing is class-like and can be instantiated multiple times.

For example, is the following also legitimate?

with pm.Model() as model:
    BoundedNormal = pm.Bound(pm.Normal, lower=0.0)
    x = BoundedNormal('x', mu=1.0, sd=3.0)
    y = BoundedNormal('y', mu=2.0, sd=1.0)

or do we need to do this:

with pm.Model() as model:
    BoundedNormal = pm.Bound(pm.Normal, lower=0.0)
    x = BoundedNormal('x', mu=1.0, sd=3.0)
    AnotherBoundedNormal = pm.Bound(pm.Normal, lower=0.0)
    y = AnotherBoundedNormal('y', mu=2.0, sd=1.0)

?

2

BoundedNormal is class-like and can be instantiated multiple times. So you can do:

with pm.Model() as model:
    BoundedNormal = pm.Bound(pm.Normal, lower=0.0)
    x = BoundedNormal('x', mu=1.0, sd=3.0)
    y = BoundedNormal('y', mu=2.0, sd=1.0)
3

If it’s not too difficult, it might be nice to put this example in the docs for Bound so that the reader recognizes this.
pm.Bound seems like a sort of odd thing – it returns an RV constructor function, if I understand correctly. It’s not a class itself, although it looks like one, and there is a bounded RV class.

4

Some more documentations would sure helps - I think it would be good to added Bound distribution to http://docs.pymc.io/prob_dists.html. including information like bounded distribution does not normalized to 1 etc. Would you like to submit a pull request ;-)?

5

Is this in docs/source/api/bounds.rst? I don’t actually know much about how the documentation is structured. If so, I could have a try. If not, please point me at the right location.

6

Oh right that’s actually a better page. Although we should definitely have a hyper link in the distribution doc page to point to the Bound doc page. I think currently it is not immediately obvious where is this information (at least it is not on the left hand side panel?)

7

I have submitted a pull request about this.

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