## CTDSX - a Collection of benchmark examples for state-space realizations of time-invariant continuous-time systems

### Daniel Kressner, Volker Mehrmann and Thilo Penzl

SLICOT Working Note 1998-9: November 1998.

This paper describes a benchmark collection for state-space realizations of time-invariant continuous-time dynamical systems. The collection is intended to provide a means for testing the correctness, accuracy, and speed of numerical methods for several problems arising in control theory. It has been implemented in FORTRAN and MATLAB.

## Subspace model identification of linear systems in SLICOT

### W. Favoreel, V. Sima, S. Van Huffel, M. Verhaegen and B. De Moor

SLICOT Working Note 1998-6: October 1998.

This paper compares 3 commonly used subspace identification algorithms N4SID, MOESP and CVA, using their MATLAB implementation, in terms of prediction accuracy, simulation accuracy and computational efficiency. The comparison is made on the basis of 15 publicly available practical datasets to which the codes are applied.

## Fortran 77 routines for H-infinity and H-2 design of continuous-time linear control systems

### Petko Hr. Petkov, Da-Wei Gu and Mihail M. Konstantinov

NICONET Report 1998-8: September 1998.

Fortran 77 routines are presented for state space design of H-infinity (sub)optimal controllers and H-2 optimal controllers for linear continuous-time control systems. The subroutines make use of LAPACK and BLAS libraries and produce estimates of the conditioning of the corresponding matrix algebraic Ricatti equations. Modified formulae are implemented in the case of H-infinity design which allows to reduce the order of the inverted matrices. The subroutines will be included in the SLICOT library.

## Parallel-SLICOT Implementation and Documentation Standards

### I. Blanquer, D. Guerrero, V. Hernandez, E. Quintana-Orti and P. Ruiz

SLICOT Working Note 1998-1: September 1998.

This paper presents the P-SLICOT (Parallel Subroutine Library in Control and Systems Theory) Implementation and Documentation Standards. Here we propose some useful guidelines for those who want to contribute to the parallel version of SLICOT. The main goal of these rules is to facilitate the work of obtaining a portable, reliable, and easy maintanable code.

## Direct formulae for the H-infinity sub-optimal central controller

### Da-Wei Gu, Petko Hr. Petkov and Mihail M. Konstantinov

NICONET Report 1998-7: August 1998.

Alternative formulae, directly based on the original data of the given interconncted system, are presented for the H-infinity sub-optimal central controller