# lmjohns3☙

• ## Speech as a Remarkable Motor Skill

In April I got to attend the annual meeting of the Society for the Neural Control of Movement, a small but interesting conference that brings together researchers in neuroscience, physiology, biomechanics, robotics, and computational modeling to discuss recent progress in motor control.

• ## Using travis-ci with miniconda, scipy, and nose

Twice in the past year I have struggled to get continuous builds and test coverage set up on Travis and Coveralls (respectively). The first time was so frustrating that I just gave up, but last week I finally got things working! I thought it would be helpful to describe what worked (and why).

• ## Using Theano on Mavericks with a Virtualenv

I updated my laptop to Mavericks some time ago, and at the same time decided to make the switch to Python 3. I’d learned that all of my trusted numeric libraries already worked with the newest Python, and several of the new language features (yield from, float division, etc.) were appealing. So almost immediately after installing Mavericks, I set up a Python 3 virtualenv:

• ## Tool Time: org-mode and Beamer

This year I’ve become a devoted user of org-mode for making presentations, using the excellent beamer package for LaTeX export. Although this tool set can produce great-looking slides, using open-source software, without using silly point-and-click tools, it does have a steep learning curve. Having gone through at least the initial phases of this curve, I hope that I can help out other folks in their presentation efforts by giving some pointers here.

• ## Swimming with Purpose

As a kid I was sort of petrified of swimming. Not to the point of phobia—I went to lessons at the Y in Coeur d’Alene and eventually passed the swim test at camp—but my brother was always the one out on the boogie board, and it was the bigger kids doing flips off the diving board. I never felt very comfortable in the water: Jumping in always made my lungs feel like they were seizing up, something about the coldness and the pressure of the water, and the instantly terrifying feeling of floating.

• ## Graph Time: March Madness

It’s March Madness ! I was looking at the brackets for the NCAA men’s basketball tournament the other day, marveling at the number of upsets in this year’s tournament. Then I remembered : wait, aren’t there a lot of upset victories every year in the tournament ?? Particularly in the early rounds ?

• ## Three Cheers for Tau

At least on Hacker News, there’s been a healthy debate going for a little while about whether tau or pi is “right.” Tau, if you haven’t seen it already, is defined as the ratio of a circle’s circumference to its radius: $\tau = \frac{C}{r}$ Pi, on the other hand, is well-known from school as the ratio of a circle’s circumference to its diameter: $\pi = \frac{C}{d} = \frac{C}{2r}$

• ## One way the bread can go wrong

L and I were gifted a beautiful, red, enameled cast iron pot this spring, for the express purpose of baking bread. I know, it sounds funny, needing a heavy pot to bake bread. But, you see, we’ve finally run across the no-knead bread technique that hit the NY Times / NPR crowd several years back, and it truly is a lovely way to make bread.

• ## Modules and Sparsity in Motor Learning

For the past few days, I’ve been reading Kevin Markey’s extremely interesting 1994 PhD thesis, “The sensorimotor foundations of phonology: a computational model of early childhood articulatory and phonetic development.” I’d have loved to write this thesis myself, nearly 20 years later! It’s been quite inspiring to read, though, because of the assumptions and other decisions that Markey made in the course of making his model tractable. I think there are a few of these assumptions that we might be able to tackle more directly now, thanks to some of the more recent tools of graphical models and the like.

• ## Another Ingredient of Greatness

Today I sat down at the Internet Vortex to check out what’s happening on Hacker News, and I was pleasantly surprised to see Dalton Caldwell topping the headlines with a very nice blog post on how Great things are made. Dalton’s point, from my reading of it, is that people who manage to do Great things are able to do so not thanks to some grand, unfathomable notion of how the world works, but at least in part because they have practiced their craft so completely that it’s become muscle memory.

• ## Masochism and Meditation

My first Vipassana retreat was a cold, foggy ten days in late December, 2009. Not having meditated much, but having thought of doing so often, I figured that I needed a long period of time devoted to learning more about the practice, and—even more importantly—actually practicing. For meditation is truly something that requires practice.

• ## Attributing Data to Latent Generators

I’m somehow fascinated by Gibbs sampling for Dirichlet Processes. Here’s how I think of the process at a high level: