Archive for September 21st, 2006

Dissection: some videos!

September 21, 2006

After reading so many PD James (five in the past three months), I was curious as to how a post mortem would look like. Pharyngula’s this post has killed that curiosity. I didn’t even get to the videos. The first page was sufficient.

Read code; write; read code; write!

September 21, 2006

It is well known that to write great code, you have to read great code:

Learning to program is like learning to write good natural language. The best way to do it is to read some stuff written by masters of the form, write some things yourself, read a lot more, write a little more, read a lot more, write some more … and repeat until your writing begins to develop the kind of strength and economy you see in your models.

Where do you get codes to read? Head to code search:

Enter search terms to find relevant sample code from nearly 700 O’Reilly books. The database currently contains over 123,000 individual examples, composed of 2.6 million lines of code — all edited and ready to use.

Link via Boing Boing.

Of course, there is nothing to beat volumes B and D of Computers and Typesetting by that master of masters, Knuth, if you want to read some real code! I have also heard some great things about the Linux kernel code by Linus.

A Maharaja and a magician of Carnatic music!

September 21, 2006

The Chennai edition of the friday review of Hindu carries an article about Jayachamarajendra Wodeyar, while the Bangalore edition carries an interview/article about Kunnakkudi.

Evolution of electrically and/or magnetically active systems!

September 21, 2006

Here is a paper titled Thermodynamicaly consistent variational principles with applications to electrically and magnetically active systems; it was published two years ago — I do not know how I missed it. Free energy expression for an inhomogeneous system is the first step towards phase field modelling; the variational derivative of the energy can then be considered as a potential that drives the system towards equilibrium, and hence, we obtain the equation for the kinetics of evolution. Thus, this paper will be the one of the starting points if you are interested in the phase field modelling of piezoelectric, magnetic, and polarizable sytems. If this interests you, here is the abstract:

We propose a theoretical framework to derive thermodynamically consistent equilibrium equations and kinetic driving forces to describe the time evolution for electrically and magnetically active materials. This procedure starts from the combined statement of the first and second laws of thermodynamics, naturally incorporates Maxwell’s equations, and accommodates the description of continuous phase transformations for conserved and non-conserved order parameters. The kinetics of conserved and non-conserved ordered parameters are introduced, the adequate gradient flow is identified, thus the appropriate kinetics (e.g., Allen–Cahn, Cahn–Hilliard) are derived. Example applications of this theory include the electromechanical fields of piezoelectric materials and the wave equation in the limit of chemically homogeneous solids. Moreover, we derive a thermodynamically consistent set of partial differential equations which describe the transport of charged species in conductive, non-polarizable, magnetizable solids, and in polarizable, electrically insulating, non-magnetizable solids.

Have fun!

Ghost dance!

September 21, 2006

Here is the ghost dance sequence from Ray‘s Goopy Gyne Bagha Byne; link via Boing Boing.