Complex Step Differentiation. This is so simple and perfect - for a real analytic function f(x), Im(f(x+ih)) = f'(z)+O(h^2). Proof is exactly what you think. Also related, which I linked to last time: Introduction to Automatic Differentiation

The MCMC Handbook.

Andrew Gelman has an …

(For my American readers, that's about $125.)

I'm currently located in Pune, India, enjoying India's excellent medical system. I just had an MRI in preparation for more serious treatments. Once I've gone through the full experience, I'll be writing a detailed blog post on the topic.

India's medical system is …

Computers are made of metal. It's an important fact to remember. It's wonderful to treat the world as being made of category theory and lambda calculus. The world of math is wonderful and I enjoy it too much. But hidden underneath all that lovely abstraction lies a much less beautiful …

Hanuman issued biometric ID card. Ganesh is still the cutest of them all.

The Log: What every software engineer should know about real-time data's unifying abstraction

Microservice Prerequisites - a good guide. Also a great reason to stick to monolithic architecture for as long as possible. Relatedly, distributed balls of mud …

A commonly asserted fact is that as an individual employee's working hours increase, his hourly productivity decreases. This is supported by a variety of studies. This naturally begs the question - why do employers often demand that employees work for long hours? Are employers simply irrational? In this post I'll use …

Attribution theory is the practice in advertising where you attempt to figure out how to allocate credit for a sale to a given advertisement. I argue that attribution theory is asking the wrong question - it doesn't matter how to allocate credit for your past purchases. What matters is how to alter your advertising portfolio to maximize your next purchases.

A Different Box of Tools, by Richard Feynman. There are two great things about this article. One is the "Feynman" method of debunking a theory - come up with simple examples that satisfy the theory yet are obviously false (typically look in mental areas different from the person cooking up the …

Scalaz Stream is a relatively new concurrency and dataflow library for Scala. Near as I can tell, it's single-box use cases are the same as Akka's, provided you don't plan to build a distributed system. I've been struggling to learn the library, and figured I'd write down my thoughts in …

Back in my days as a physicist, my Ph.D. adviser came to me with a proposed theory. He wanted to study the many-body Schrodinger equation - to study the interaction of a single charged particle with a conductive screen. I didn't like this theory very much - it offended my sensibilities …

In a groundbreaking work back in 1975, Scott Alexander made a prediction of dire environmental consequences by the year 2015 if we don't change our behavior. His book No Limits to Bears predicts an upcoming bearpocalypse and so far his predictions seem pretty accurate - I ran a statistical test and …