Infer returns dist object, not the distribution

[Hakan Kjellerstrand]

Some months ago I started to learn webbpl but after a while realized that I had to brush up my JavaScript skills so I haven't done much webppl since then.

However, today I started to test some webppl models that worked before but don't work as expected anymore. For example the following simple binomial model:

""""

var binomial = function() {

      var a = sample(Bernoulli({ p: 0.5 }))

      var b = sample(Bernoulli({ p: 0.5 }))

      var c = sample(Bernoulli({ p: 0.5 }))

      return a + b + c

}

var binomialDist = Infer({ model: binomial })

display(expectation(binomialDist)) display(binomialDist)

"""

Before it printed the following:

 $ webppl binomial.wppl

"""

Marginal:

     1 : 0.3750000000000001

     2 : 0.3750000000000001

     0 : 0.12500000000000003

     3 : 0.12500000000000003

"""

However, now it displays just the dist object:

 $ webppl binomial.wppl

"""

dist {

    params: {

      dist: { '0': [Object], '1': [Object], '2': [Object], '3': [Object] } },

     supp: [ 0, 1, 2, 3 ],

     getDist: [Function (anonymous)]

}

"""

Note that some functions works, such as expectation for the model above:

"""

    display(expectation(binomialDist))

"""

It prints 1.5000000000000004

I'm running everything in a LInux Ubuntu 18.04 LTS machine.

* webppl version:

HEAD v0.9.15-258938e /home/hakank/.nvm/versions/node/v14.5.0/lib/node_modules

  U

/webppl

* node version: v14.5.0

  /home/hakank/.nvm/versions/node/v14.5.0/bin/node

As indicated, I've installed webppl with

    $ npm install -g webppl

and using nvm for setting the node.js version.

When playing JavaScript I did a lot of things such as installing different versions of node.js, installed a lot of different npm modules etc, so the environment is not at all the same as when I first tested webppl.  So I must have done some weird stuff...

Does anyone know how to restore a working version/environment? Have I forgot to install some packages or just done some newbie mistake in my model?

Best regards,

Hakan

[null-a]

I wonder if you're running into this:

https://github.com/probmods/webppl/issues/933

If so, reverting to an earlier version of Node might be the easiest solution.

[Hakan Kjellerstrand]

Ah, yes reverting to node.js version v10.22.0 works. Thanks for the tip.  (I thought I tested this but must have missed something.)

Do you if there are any later version than v10.22.0 of node.js that works with webppl regarding this problem?

Best,

Hakan

[null-a]

Great. I don't recall anything beyond what's mentioned in the issue I linked to. So, it sounds like the v11 series might work, but I'm not sure.

[Hakan Kjellerstrand]

I tested node.js v11.0.0 and v11.15.0. Both have the same problems displaying distributions as reported above.

So I'll settle with v10.22.0.

Thanks for your help!

/Hakan

[null-a]

No problem! Thanks for letting us know which versions worked.