Existence does not imply correlation (or causation)

A while back I had a problem - a spike in latency on the east coast. Log messages on the east coast were taking 50ms, whereas west coast messages were under 1ms. This was bad. I started probing for the answer, poking around my east coast servers and looking for the ...

Spaced Repetition is Awesome: Two App Recommendations

I've recently become motivated to learn Portuguese. Mulheres bonitas sao muito motivado. It's not the first time this has happened to me - in the past I've attempted to learn Spanish, Farsi and Konkani. But it is the first time I've made significant progress and it's ...

Bounded Rationality and the Ellsberg Paradox

The Ellsberg paradox is a puzzle concerning human rationality. It postulates a scenario involving an urn with 90 balls inside - 30 red ones, while the remaining 60 can be yellow or black. A player gets to draw a ball from the urn, and receives a payoff dependent on the color ...

Sam Altman defeats the Sexist Straw Man

Sam Altman recently wrote an article about sexism in technology. And while I don't dispute many of his factual claims, it's important to recognize the claims he didn't make, and to recognize that most of the article is merely attacking a straw man. Unfortunately, logical fallacy, emotional ...

Topology of decisionmaking - are you secretly managing by metric?

Suppose you have a method of making decisions that doesn't suck - i.e., one that is objective, consistent, and never leaves you guessing about what to do. The mathematical field of topology provides a wonderful theorem - if you have a good decision process, it is equivalent to managing by metric.

Strength is a category theoretical property which is known to be boring - every Monad in Hask (and similarly Scal) satisfies it. The question arises - what about it's dual, Costrength? What would a Costrong Comonad look like? Is it interesting? It turns out the answer is no - every Comonad in Hask/Scal is Costrong. In this post I'll provide a brief tutorial on Comonads and show why every Comonad is also Costrong. You do NOT need to know much category theory to follow this post, but some familiarity with the everyday programming of Monads will be helpful.

How to return an array of generic type, or "cannot find class tag for element type T"

I was recently writing some Scala code, and I wanted to return an array of generic type:

class Foo[+T] {
def someArray(size: Int): Array[T] = {
val result = new Array[T](size)
...
result
}
}

This did not make Scala happy:

[info] Compiling 1 Scala source to /home/stucchio/src/breeze/math ...