jtobin.io

Byzantine Generals and Nakamoto Consensus

You can recognize truth by its beauty and simplicity.

– Richard Feynman (attributed)

• consensus

Recursive Stochastic Processes

Last week Dan Peebles asked me on Twitter if I knew of any writing on the use of recursion schemes for expressing stochastic processes or other probability distributions. And I don’t! So I’ll write some of what I do know myself.

• statistics
• recursion
• haskell

The Applicative Structure of the Giry Monad

In my last two posts about the Giry monad I derived the thing from its categorical and measure-theoretic foundations. I kind of thought that those posts wouldn’t be of m...

• mathematics
• statistics
• haskell

Implementing the Giry Monad

In my last post I went over the categorical and measure-theoretic foundations of the Giry monad, the ‘canonical’ probability monad that operates on the level of probability measures.

• mathematics
• statistics
• haskell

Foundations of the Giry Monad

The Giry monad is the canonical probability monad that operates on the level of measures, which are the abstract constructs that canonically represent probability distributions. It’s sort of the baseline by which all other probability monads can be...

• mathematics
• statistics
• haskell

Rotating Squares

Here’s a short one.

• haskell
• recursion

Promorphisms, Pre and Post

To the.. uh, ‘layperson’, pre- and postpromorphisms are probably well into the WTF category of recursion schemes. This is a mistake - they’re simple and useful, and I’m going to try and convince you of this in short order.

• haskell
• recursion

Comonadic Markov Chain Monte Carlo

Some time ago I came across a way to in-principle perform inference on certain probabilistic programs using comonadic structures and operations.

• probabilistic-programming
• language-engineering
• haskell

A Simple Embedded Probabilistic Programming Language

(This article is also published at Medium)

• probabilistic-programming
• language-engineering
• haskell

Randomness in Haskell

Randomness is a constant nuisance point for Haskell beginners who may be coming from a language like Python or R. While in Python you can just get away with something like:

• haskell

On Measurability

.. this one is pretty dry, I’ll admit. David Williams said it best:

• mathematics

Making a Market

(This article is also published at Medium)

• probability
• statistics

flat-mcmc Update and v1.0.0 Release

I’ve updated my old flat-mcmc library for ensemble sampling in Haskell and have pushed out a v1.0.0 release.

• haskell
• statistics

Encoding Statistical Independence, Statically

(This article is also published at Medium)

• haskell
• statistics
• language-engineering

Time Traveling Recursion Schemes

In Practical Recursion Schemes I talked about recursion schemes, describing them as elegant and useful patterns for expressing general computation. In th...

• haskell
• recursion

Monadic Recursion Schemes

I have another few posts that I’d like to write before cluing up the whole recursion schemes kick I’ve been on. The first is a simple note about monadic versions ...

• haskell
• recursion

Sorting Slower with Style

I previously wrote about implementing merge sort using recursion schemes. By using a hylomorphism we could express the algorithm concisely and true to its high-level descr...

• haskell
• recursion

Yo Dawg We Heard You Like Derivatives

I noticed this article by Tom Ellis today that provides an excellent ‘demystified’ introduction to automatic differentiation. His exposition is ...

• haskell
• language-engineering
• recursion

A Tour of Some Useful Recursive Types

(This article is also published at Medium)

• haskell
• recursion

Sorting with Style

Merge sort is a famous comparison-based sorting algorithm that starts by first recursively dividing a collection of orderable elements into smaller subcollections, and then finishes by recursive...

• haskell
• recursion

Markov Chains à la Carte

(This article was originally published at Medium)

• haskell
• statistics

Practical Recursion Schemes

(This article was originally published at Medium)

• haskell
• recursion

Automasymbolic Differentiation

Automatic differentiation is one of those things that’s famous for not being as famous as it should be (uh..). It’s useful, it’s convenient, and yet fewer know about it than one would think.

• language-engineering
• haskell

Sharing in Haskell EDSLs

Lately I’ve been trying to do some magic by way of nonstandard interpretations of abstract syntax. One of the things that I’ve managed to grok along the way has been the problem of sharing in deeply-embedded languages.

• language-engineering
• haskell

Basic EC2 Management with Ansible

(UPDATE 2016/08/15: Here be monsters. This code is ancient, the style is not really idiomatic Ansible, and it’s likely that nothing works anymore.)

• infrastructure