Brandon T. Willard

Results 202 issues of Brandon T. Willard

We should introduce a few basic macros and interface changes so that running `miniKanren` from [Hissp](https://github.com/gilch/hissp) and [Hy](https://github.com/hylang/hy) will behave just like it does in standard Lisp implementations (e.g. a...

enhancement

This PR updates the `pymc3-hmm` codebase so that it works with PyMC3 `v4`. - [x] Finish converting `DiscreteMarkovChain` - [x] Convert `FFBSStep` - [ ] Convert `TransMatConjugateStep` This requires the...

enhancement
important

We can use the truncated DP mixture approach given [in the PyMC3 examples](https://docs.pymc.io/notebooks/dp_mix.html#Dirichlet-process-mixtures) to estimate the number of mixture components. Let's see how well that works with our HMM models...

Posterior predictive sampling takes considerably longer than model estimation itself, and that's completely unreasonable! Last time I tried, the new [`fast_sample_posterior_predictive`](https://github.com/pymc-devs/pymc3/blob/master/pymc3/distributions/posterior_predictive.py#L124) function wouldn't work with our custom distribution classes. If...

enhancement
help wanted
important

We should see if our implementations can be converted to JAX, and whether or not that offers any performance advantages. We start by attempting conversion (e.g. using [`jax_funcify`](https://github.com/pymc-devs/Theano-PyMC/blob/master/theano/sandbox/jaxify.py#L156)) of our...

enhancement

There are a few straightforward things we can do to improve sampling performance: - Re-use allocated log-likelihood arrays - These arrays can be fairly large (i.e. length of the series...

enhancement

We need to create some toy/example series and build tests around them. See the examples [here](https://github.com/brandonwillard/amimodels/blob/master/tests/test_step_methods.py#L30) for reference.

In cases for which we are only estimating Poisson rate parameters, it would be nice to have a simple conjugate sampler when we set gamma priors (on the rate parameters)....

enhancement

The [Conway-Maxwell-Poisson distribution](https://en.wikipedia.org/wiki/Conway%E2%80%93Maxwell%E2%80%93Poisson_distribution) offers another way means of capturing over- and under-dispersion in a Poisson-like framework. It has also been [studied under HMM models](https://www.tandfonline.com/doi/abs/10.1080/00031305.2018.1505656?journalCode=utas20) and shown to "cope with the...

enhancement

We need some simple unit tests that confirm proper estimation of the initial state probabilities (e.g. `gamma_0` with a Dirichlet prior in most of our models).

good first issue