Whenever I find a topic I can’t find a sufficiently good tutorial or explanation of online, I feel compelled to offer one. I hope this helps you.

The hypergeometric distribution describes the probability of events in the following scenario:

Suppose you have a jar containing 10 red marbles and 90…


tldr: “Ridge” is a fancy name for L2-regularization, “LASSO” means L1-regularization, “ElasticNet” is a ratio of L1 and L2 regularization. If still confused keep reading…

Logistic Regression

This article is about different ways of regularizing regressions. In the context of classification, we might use logistic regression but these ideas apply just as well to any kind of regression or GLM.

With binary logistic regression, the goal is to find a way to separate your two classes. …


“ ‘All models are wrong, but some are useful.’

So proclaimed statistician George Box 30 years ago, and he was right. But what choice did we have? Only models, from cosmological equations to theories of human behavior, seemed to be able to consistently, if imperfectly, explain the world around us…


Reflections from Tufts Polyhack, October 23–24, 2015

Some four years ago, I attended Tufts’ first hackathon put on by Marshall, and it changed the course of my life in a pretty profound way. …


Climbing rocks is probably the best way I know of to slowly lose all your time and money. There is hardly a better way of doing so.

I was climbing near Aspen, CO, when the opportunity arose to go to southern Utah to see my godfather’s daughter (also my father’s…


For me, Climbing is yoga on a vertical surface. It’s a negotiation between your will and gravity, and demands a holistic self-discipline I had been craving without knowing it. And its unfathomably addictive.

I started rock-climbing on a whim. Sometime in early October of last year, a friend invited me…


I registered my domain foo.com through google domains, and then I setup email forwarding so that emails sent to alex@foo.com go to alex@gmail.com, but now I want to send email from alex@foo.com.

Well, I went through the support channels at Google domains — so you don’t have to.

To set…


An analogy with the Neural Network Algorithm

I’m going to try and explain to you why I believe discussions on the subject of ethics, especially of the abstract variety, in which seemingly well warranted postulations about the nature of morality abound, are not only entirely futile but morally hazardous. …


Despite what others tell you, it can be done.

Overlooking Glaciar Grey near the top of the pass.

Torres Del Paine is one of the great natural treasures on the face of this planet, and a friend and I recently had the great pleasure of experiencing it. The Torres were the first stop in our Patagonian expedition, which was all too short, and wanting to do as much…


In response to The Economist’s The Future of the Book

To me, the really fascinating thing about books is the ecosystem they've given rise to. Books have essentially promulgated a set of cultural artifacts and institutions which allow them to replicate and disseminate themselves safely throughout our world. …

Alex Lenail

conscious mammalian organism, fanatical tea snob.

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