Alexey Radul

Results 125 issues of Alexey Radul

on the grounds that the derivation is long enough that it should be tested. For instance, one could test that gradient ascent recovers the correct parameter values on an example...

Effort: k min/hr
Reason: Better testing
Probabilistic

Venture Lite fails to rejection sample an annoyingly large class of models that should be amenable to rejection sampling. For instance, consider the collapsed version of the Dirichlet process clustering...

Status: Needs design
Reason: Incremental Improvement
Probabilistic

Slice sampling suffers from a milder version of #384. Consider doing slice sampling on a variable with a beta prior. While looking for the region to slice over, the slice...

Reason: Fix bugs
Status: Needs design
Reason: Blocking DP Chapter
Probabilistic

The basic idea called "Griddy Gibbs" is that one can (approximately) Gibbs-sample from any unnormalized 1-dimensional continuous posterior density by just doing the quadrature. Somehow this idea has gotten metamorphosed...

Effort: k days
Reason: Complete capability
Probabilistic

I have [recently thought](http://alexey.radul.name/ideas/2016/on-testing-probabilistic-programs/) about this in the abstract, and I mean to organize my thoughts into a concrete proposal for improving the usefulness of Venture's test suite. The resulting...

Reason: Better testing
Effort: ~1 day
Status: Needs design
Status: Needs plan
Probabilistic

Venture has only one nesting level of "particles", which can be used either for running N independent Markov chains (by `(resample N)` once at the beginning and not otherwise), or...

Reason: Complete capability
Status: Needs design
Status: Needs plan
Probabilistic

Can we do better than 0? The definition is the maximum over all possible initial vectors and transmission and emission matrices of the marginal probability of the observations, integrating out...

Reason: Performance
Status: Needs math
Probabilistic

Custom multinode blocks introduce a correctness problem that does not occur with single-site proposals. To wit, what happens if a block proposal changes the membership of the block being proposed...

Reason: Fix bugs
Status: Needs math
Status: Needs plan
Probabilistic

Consider the following innocent-looking program: ``` [assume coin (flip)] [assume coin2 (if coin (flip) (flip))] [infer (gibbs default all 1)] ``` One would think that this would lead to the...

Status: Blocked
Effort: Project
Reason: Incremental Improvement
Probabilistic

For example, `reportKnownGaussian` could use the K-S test to check the shape of the distribution, and also the Z test to check its mean. This might be desirable due to...

Effort: k min/hr
Reason: Better testing
Probabilistic