Friday, January 4, 2013

Scientific Computing Going Mobile/Embedded

I follow both the Octave and Maxima user mailing lists (I learn more from the Maxima list, but the Octave one still throws up a gem every now and then). I am also a founding member of the Dayton Diode hackerspace. So it was interesting to see some things of interest to makers/hackers pop-up on those two lists.

The first was a thread on the Octave list about installing Octave and the Octave Forge packages on a Raspberry Pi. In theory it should be as easy as any other Debian system using the package manager for the distribution. No word back from the OP yet on whether it works in practice or not.

The second thread to pop up was on the Maxima list about installing Maxima on Android systems. Maxima-on-Android is apparently a bundle on Google Play of Maxima 5.28.0, Gnuplot 4.6, Mathjax 2.1 and Qepcad 1.69. I have not played with it yet on any of my Android devices.

Thursday, January 3, 2013

National Strategy for Advancing Climate Modeling


NAP has a new report out on a national strategy for advancing climate modeling. I've just done a quick skim so far. Some tidbits below that touch on V&V and uncertainty.

Wednesday, December 19, 2012

Octet Truss for Topology Optimization

Random Octet Truss Array (on shapeways)
This post demonstrate a work-flow for topology optimization using open source tools (with mixed success). The approach uses an unpenalized method (see wiki) that maps the material density output from the optimizer to unit-cells based on the octet truss (inspired by this white paper, see pp10). As some further motivation for this approach, the students working on the record-setting human powered helicopter demonstrated that multi-scale trusses (trusses with elements made of smaller trusses) were a very efficient structural concept (see the comments for further references on multi-scale structures). One of the benefits of not penalizing (using variable density solutions rather than trying to achieve predominantly solid-void solutions) is that we don't need to spend time doing parameter continuation on the penalization exponent.

Monday, December 17, 2012

Interesting Developments in the Numerical Python World

From Travis Oliphant by way of the Planet Scipy feed:
Hello all,

There is a lot happening in my life right now and I am spread quite thin among the various projects that I take an interest in. In particular, I am thrilled to publicly announce on this list that Continuum Analytics has received DARPA funding (to the tune of at least $3 million) for Blaze, Numba, and Bokeh which we are writing to take NumPy, SciPy, and visualization into the domain of very large data sets. This is part of the XDATA program, and I will be taking an active role in it. You can read more about Blaze here: http://blaze.pydata.org. You can read more about XDATA here: http://www.darpa.mil/Our_Work/I2O/Programs/XDATA.aspx

I personally think Blaze is the future of array-oriented computing in Python...

Passing the torch of NumPy and moving on to Blaze

Thursday, December 13, 2012

Open Source Topology Optimization for 3D Printing

Rough Hex Output & Smooth Surface Reconstruction for Dogleg
This post describes a set of open source tools for simple topology optimization for parts destined for 3D printing. The two Matlab codes (both are plain vanilla Matlab, so they work successfully in Octave too) are good introductions to topology optimization. The papers that go along with the codes provide great documentation and examples of tweaking and changing the scripts to treat various problems. The python implementation is more capable (and a few more lines of code).

Sunday, November 4, 2012

Fedora BRL-CAD Compile Notes


I have not had good luck with the Boolean operations in FreeCAD as I had hoped (seems to be a problem with the underlying OpenCascade libraries) so I am compiling BRL-CAD.

Sunday, October 21, 2012

F-35A GBU-31 Safe Sep Video

Nice separation video near the end; bearably cheesy at the beginning.

Monday, October 8, 2012

OpenFoam on Google Compute Engine

I signed up for the free preview of Google Compute Engine. The project I described in their questionaire was basically just some hobby-level CFD stuff, so I am surprised they sent me an invite. This post provides links to the initial setup documentation and getting started tutorials, and describes getting OpenFoam up and running on an instance.

Sunday, October 7, 2012

Falcon 9 Flight 4, CRS-1

Congratulations to SpaceX on their successful launch of the first commercial resupply mission to the International Space Station!