Bifurcation Analysis with XPP

This is a continuation of last week's post. I had some troubles getting the graph that I wanted, but Bard Ermentrout (the creator of XPP) fixed the problem in a sentence via email (lesson: when stuck, don't be afraid to ask the experts). There will be many technical terms which won't be elaborated on in this post. I encourage the reader who want to follow along to look up things they are not familiar with on Wikipedia. The post assumes you have some familiarity with bifurcation analysis (the qualitative study of ODEs).

XPP - quirky but declarative and interactive

Complex systems in fields like System Biology can often be described as a set of differential equations. These differential equations represents how species like proteins and enzymes change over time during various circumstances, like differing initial conditions and parameters. The behavior of the system corresponds to various biological phenomena like cell differentiation. Usually one has a bunch of these equations, based on experiments, assumptions or both, and want to figure out how the system, say, a cell, behaves. XPP is a tool that makes this easy.

Decade dollars and using the right level of precision

A couple of years ago I was referring a article about a company which had seen tremendous growth in a very short period of time. It was a Swedish company that had somehow established itself in Russia but with very little exposure in the Swedish press at all. A guy asked me, surprised at not having heard of this company, how many employees they had. My answer? I think it was 500, but it could have been 50.

How are you spending your time?

Going through Hacker School for the first time this summer made me more familiar with the landscape of programming. I began to see patterns, and with that, paths. I know what kind of things interest me and what I want to get good at. This is my list of things I am either learning right now or want to learn during my second time around. The first half consists of things to do, and the last half of general themes.