# MPI debugging

MPI programs are more difficult to debug than other programs because of their parallel nature. The MPI programming model follows the single program multiple data paradigm or the multiple program multiple data paradigm. Debugging MPI programs is complicated by the following characteristics: Several processes run in parallel in a coordinated way. These processes may all… Continue reading MPI debugging

Uncategorized

# Cell phone supercomputers

In “Physics of the Future” Michio Kaku states “Today your cell phone has more computer power than all of the NASA back in 1969, when it placed two astronauts on the moon.” and in the fictional movie “Iron Sky” the space ship “Götterdämmerung” is operated by a smart phone. So what is actually the computational… Continue reading Cell phone supercomputers

Uncategorized

# Integer overflow

YouTube Error: An integer overflow occurred. On YouTube a video has been watched more than 2,147,483,647 times, a number that can not been represented by a (signed) 32-bit integer.

Uncategorized

# Some Math

Math in WordPress has become as easy as $1,2,3,\dots$ thanks to MathJax. Some trigonometric identities: \begin{gather} \sin\alpha^2 +\cos\alpha^2 = 1 \\ \sqrt{2}\left|\cos(\alpha/2)\right| = \sqrt{\cos(\alpha) +1} \end{gather} The Dirac equation for a relativistic electron: \begin{equation} \mathrm{i}\hbar\frac{\partial\Psi(\vec{r}, t)}{\partial t} = \left(c\vec{\alpha}\cdot\left(\hat{\vec{p}}- q \vec{A}(\vec{r}, t) \right) + q \phi(\vec{r}, t) + mc^2\beta \right)\Psi(\vec{r}, t) \end{equation}

# TRNG now on GitHub

As I pointed out earlier the open source software repository BerliOS will be closed at the end of this year. For this reason, Tina’s Random Number Generator Library is on GitHub now. You may checkout the whole version history starting from version 4.0 to the latest version 4.13 from the repository rabauke/trng4.

Uncategorized

# Computenik 2.0

The Sputnik crisis shocked the US policy as well as the US science in 1957 when the Soviet Union launched Sputnik 1, the first Earth satellite. The launch of Sputnik 1 showed clearly that the US had lost its leadership in space technology. In 2002, the Computnik crisis followed when Japan introduced its Earth Simulator,… Continue reading Computenik 2.0

# Scientific Python

From time to time students ask me what might be the best programming language for computational physics and numerical applications. For a long time my standard answer to this question was twofold: The language does not matter, learn C++! On the one hand, I think one should not bother to much with this issue because… Continue reading Scientific Python