SiMpLIfy: A Toolbox for Structured Model Reduction
  In this paper, we present a toolbox for structured model reduction developed for MATLAB. In addition to structured model reduction methods using balanced realizations of the subsystems, we introduce a numerical algorithm for structured model reduction using a subgradient optimization algorithm. We briefly present the syntax for the toolbox and its features. Finally, we demonstrate the applicability of various model reduction methods in the toolbox on a structured mass-spring mechanical system. 
Martin Biel, Farhad Farokhi, Henrik Sandberg
math.OC cs.SY