© National Instruments Corporation 1-1 Xmath Model Reduction Module
1
Introduction
This chapter starts with an outline of the manual and some useful notes. It
also provides an overview of the Model Reduction Module, describes the
functions in this module, and introduces nomenclature and concepts used
throughout this manual.

Using This Manual

This manual describes the Model Reduction Module (MRM), which
provides a collection of tools for reducing the order of systems.
Readers who are not familiar with Parameter Dependent Matrices (PDMs)
should consult the Xmath User Guide before using MRM functions and
tools. Although several MRM functions accept both PDMs and matrices as
input parameters, PDMs are preferable because they can include additional
information that is useful for simulation, plotting, and signal labeling.

Document Organization

This manual includes the following chapters:
• Chapter 1, Introduction, starts with an outline of the manual and some
useful notes. It also provides an overview of the Model Reduction
Module, describes the functions in this module, and introduces
nomenclature and concepts used throughout this manual.
• Chapter2, Additive Error Reduction, describes additive error
reduction including discussions of truncation of, reduction by,
andp erturbation of balanced realizations.
• Chapter3, Multiplicative Erro r Reduction, describes multiplicative
error reduction presenting considerations for using multiplicative
rather than additive error reduction.
• Chapter4, Frequency-Weighted Error Reduction, describes
frequency-weighted error reduction problems, including controller
reduction and fractional representations.