LYAPACK 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 Lyapunov equations. In contrast to the 'lyap' and 'dlyap' command in the MATLAB Control toolbox it uses iterative algorithms and is intended for large, sparse problems. The contents of the subdirectories are: demos - some demo programs examples - data and routines for generating test examples guide - the user's guide (ps file and pdf file) routines - the actual LYAPACK routines usfs - so-called user-supplied functions for most common types of problems To get started: - run a few demo programs: + change into the installation directory and run 'lstartup.m' to set some paths + for solution of Lyapunov equations: run 'demo_l1' + for model reduction: run 'demo_m1' or 'demo_m2' + for Riccati equations and linear-quadratic optimal control problems: run 'demo_r1' - consult the user's guide: guide/guide.ps - to see how user-supplied functions work: run 'demo_u1', 'demo_u2', or 'demo_u3' Further notes: - You might have to change the MATLAB paths in 'lstartup.m' - LYAPACK is intended to be used in a UNIX environment. Note that a few LYAPACK routines do not conform with the DOS-like naming convention 'xxxxxxxx.yyy' for file names. Hence one needs at least Windows 95 or better. - The most up-to-date version of this toolbax can be found at http://www.tu-chemnitz.de/sfb393/lyapack - For questions, comments etc. contact Volker Mehrmann at mehrmann@mathematik.tu-chemnitz.de LYAPACK Version 1.0 Thilo Penzl, Nov.18, 1999