NumPy and SciPy rely on BLAS and LAPACK for basic linear algebra functionality like matrix-vector multiplication, linear system solves, or routines for eigenvalue computation. The Intel Math Kernel Library (MKL) is a mathematics library providing amongst other things fast and multithreaded implementations of BLAS and LAPACK. In this blog post, I describe how to compile NumPy and SciPy with the Intel compilers using Intel MKL on Linux. Note NumPy and SciPy can be linked to MKL without the Intel compilers by providing the proper linker options to, e.g., GCC, and I will briefly explain this as well.

Continue reading Building NumPy and SciPy with Intel Compilers and Intel MKL →

In this post, I will explain why you should start to phase out DECT and how you can do this with VoIP (Voice over IP, also known as Internet telephony) over Wi-Fi. This guide allows you to attach several wireless devices to your landline and it permits calls among all telephones in your household. Moreover, the guide provides encrypted wireless communication, it uses off-the-shelf consumer products, and works worldwide. On the downside, the voice quality may be worse unless your router supports WMM (Wireless Multimedia Extensions) and you may need a WLAN repeater because DECT tends to have higher range than WLAN. (Surprisingly, the electronics markets in my vicinity offer dual-band WLAN repeaters with 600 MBit/s transfer rate fitting into a wall socket costing no more than the cheapest DECT repeater.) If so desired, you can continue to use your existing DECT phones but communication with these devices is not guaranteed to be encrypted.

You can follow this guide if you have

• an account with an Internet telephony provider,
• your Internet router is a Wi-Fi hotspot,
• the Internet router manages your landline,
• the Internet router allows wireless VoIP telephony using SIP, and
• a mobile device with Wi-Fi as well Android, iOS, or Windows.

Continue reading More Secure Wireless Telephony with VoIP over Wi-Fi →

LAPACK (Wikipedia) provides numerically stable and fast implementations of linear algebra algorithms. In this post I will explain how to compile stetester, a testing infrastructure for LAPACK's symmetric eigensolvers.

Continue reading How to Compile stetester →