Link: The Sound Of Mandelbrot Set

The Ripples blog  published a very nice post about “sonifying” the Mandelbrot set. The resulting sound files (linked in the post) are quite interesting, especially the “SlowDivergence” soundbite. The post also tipped me off about  playitbyr, an R package that converts a data.frame (a table of values) into an auditory graph. The soundbites demoed on the webpage are really cool — you should check them out!

The sonification window of Systemic v1.
The sonification window of Systemic v1.

The “classic” version of Systemic (v1, Java) has a feature for sonifying the orbital dynamics of exoplanets, originally written by Aaron Wolf (now a Turner Postdoctoral Fellow at the University of Michigan).

Non-interacting planets only generate pure sine-wave tones — not very interesting. It gets much more exciting once you introduce planetary interactions. Resonant and unstable systems, in particular, generate much more delicate or dramatic samples. has a few posts about the sonification feature, with downloadable soundbites.

I have not been a very good steward of this feature — it didn’t make it into Systemic2 (or the web app) since I didn’t want to work on migrating the Java code.  The existence of playitbyr, though, means I do not have to reinvent the wheel, definitely reigniting my interest in implementing this feature!

[Via R-bloggers.]

Link: Zooniverse Disk Detective

Disk Detective is the newest Zooniverse citizen science project.  Volunteers delve into more than 500,000 objects seen at different wavelengths, and help pick out potential circumstellar disks.

An animated gif I made scrolling through different wavelengths on Disk Detective.
An animated gif I made scrolling through different wavelengths on Disk Detective.

The idea is super cool, the bit of classifying I did was fun, and the website looks great. Outstanding job!

Erika Nesvold has a nice writeup of the project on Astrobites.

Two useful tools: git-flow and git-gutter+

This is just a quick post linking to two very useful tools I just started incorporating into my workflow.

The first is git-flow. Git-flow gives a very nice structure to feature development using git: it imposes some discipline on branching and committing features to the “master” branch, while also providing a very helpful branching naming scheme and a clear path from developing a feature to incorporating it into a release. This post gives a clear overview on how to get started with it.

Fringe Git indicators in Emacs.
Fringe Git indicators in Emacs.

The second is an Emacs package called git-gutter+ (in its “fringe” flavor). It lets you view Git changes directly from the current buffer (the graphical symbols in the fringe shown in the screenshot). Install it from the package manager (MELPA) and add to one of your .el initialization scripts.

Link: Why I’m betting on Julia

Evan Miller: Why I’m betting on Julia

Julia looks to me like a very promising programming language.  Its main appeal is bringing C-like speed to a high-level, well-designed language that is tailored to scientific computation. From the article:

I hesitate to make the comparison, but it’s poised to do for technical computing what Node.js is doing for web development — getting disparate groups of programmers to code in the same language. […]

If you work in a technical group that’s in charge of a dizzying mix of Python, C, C++, Fortran, and R code — or if you’re just a performance-obsessed gunslinging cowboy shoot-from-the-hip Lone Ranger like me — I encourage you to download Julia and take it for a spin.

The “dizzying mix” is very much how I would describe a lot of the code I use and write on a daily basis.  R is too slow for intensive computations, so I drop down to C to write most of my algorithms and then wrap the C code in a higher-level R interface (via FFI); a similar state of affairs exists for Python. Getting communication right between the two worlds (the low-level C and the high-level language) can be daunting, and frankly, the mental context switch is exhausting. (Let’s not even bring Fortran into the discussion.)

I really hope Julia will succeed. What it needs right now is a first-class plotting facility and a bit more widespread adoption, but once that is achieved, I think that Julia will be a serious contender for mindshare.