## MESS (Matrix Equation Sparse Solver)

MESS is a MATLAB toolbox (i.e., a set of MATLAB routines) for the solution of certain large scale problems in control theory, which are closely related to Matrix equations (like Lyapunov or Riccati equations). It uses iterative algorithms and is intended for large, sparse problems. It is the successor of the LyaPack toolbox which released first in 2000. Since 2009 we develop an additional C library to exploit the capabilities of modern computers. ...more

## FlexiBLAS

The BLAS library is one of the central libraries for the implementation of numerical algorithms. It serves as the basis for many other numerical libraries like LAPACK, PLASMA or MAGMA (to mention only the most obvious). Thus a fast BLAS implementation is the key ingredient for efficient applications in this area. However, for debugging or benchmarking purposes it is often necessary to replace the underlying BLAS implementation of an application, e.g. to disable threading or to include debugging symbols. We present a novel framework that allows one to exchange the BLAS implementation at run-time via an environment variable. Our concept neither requires relinkage, nor recompilation of the application. Numerical experiments show that there is no notable overhead introduced by this new approach. For only a very little overhead the framework naturally extends to a minimal profiling setup that allows one to count numbers of calls to the BLAS routines used and measure the time spent therein. ... more