Checking your multicore computer

In February we released an update of the 3D AMaze programs for 64 bit multicore computers. Time-intensive activities are divided between multiple processors to give a substantial reduction in run time. The programs (compiled with Intel FORTRAN 11) incorporate OpenMP routines (http://openmp.org/wp/). A previous article described benchmark tests of the Magnum program (http://fieldp.com/myblog/2009/magnum-in-parallel/). We have created [...]

Theory and applications of the Maxwell stress tensor

The Maxwell stress tensor may be used to calculate electric and magnetic forces on objects. The method is seldom introduced in introductory texts on electromagnetism. Advanced texts often present the Maxwell stress tensor as a mathematical abstraction without explaining why is is useful. In reality, the method is critical for practical force calculations in numerical codes. [...]

Mind over numbers

With computers of increasing speed and power, it’s tempting to use numerical methods for everything. Because I’m old school (or maybe just old), I always enjoy a calculation where a few minutes of thought can circumvent hours wasted on the computer.

I was recently asked by a manufacturer to prepare a demonstration showing how to use Magnum [...]