Random walks.

Random walks.

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A reparameterization of the Weibull distribution

Real-world data is often messy. There may be completely spurious measurements, like a negative value when the parameter is defined to be positive. Or there may be outliers that do not meaningfully represent the underlying process. In these situations, quantiles (aka percentiles) are often used as descriptive statistics because of

An exponential encounter

I recently learned about a neat technique, invented by John von Neumann, for generating random samples from an exponential distribution (probability density $e^{-x}$). The algorithm can be generalized to sample from a normal distribution. One notable feature of von Neumann's approach, in addition to its simple brilliance,

Elixir Drop: Mergesort

In this Drop, I'll walk through the Elixir implementation of Mergesort, a well-known sorting algorithm and one of the earliest divide-and-conquer algorithms developed for digital computers. This is as much a fun exercise as it is a demonstration of how one common algorithm can be implemented in a

How long is a satellite visible from the ground?

It's a clear, dark night. You look up and gaze at the stars, shining reminders that the universe is vast and wonderful. While you're peacefully basking in the light of distant suns, you notice one bright dot is out of place. It's moving. But

Beyond unification: A little logic language

In Unification in Elixir, I describe in detail how to implement the unification algorithm. Through two small examples, I also hint at how new layers can be added that make it possible to process more complex logical expressions. In this post, I carry these ideas forward to develop a little

Unification in Elixir

Pattern matching is a pervasive and powerful tool in Elixir. This isn't too surprising if you know a little about the history of Elixir's parent language, Erlang. Erlang was originally inspired by and written in Prolog, a logic programming language where pattern matching has first-class support.

Elixir Drop: Pinning in comprehensions

This is a short one. Just a little drop of Elixir--a droplet, even. One of the things I most appreciate about Elixir is the pervasiveness and consistency of pattern matching. Pattern matching can be used almost everywhere, even when you least expect it. Recently, I had a little problem involving

Timing expressions in Elixir

Have you ever added or updated a piece of code and wondered, how long does this take to run? Does it take a millisecond? An hour? How does the time change if parameters are nudged one way or another? These are common benchmarking questions. For all serious benchmarking needs, Benchee