Scilab is a free open-source software package for scientific computation. It includes hundreds of general purpose and specialized functions for numerical computation, organized in libraries called toolboxes, which cover such areas as simulation, optimization, systems and control, and signal processing. One important Scilab toolbox is Scicos. Scicos provides a block diagram graphical editor for the construction and simulation of dynamical systems. The objective of this book is to provide a tutorial for the use of Scilab/Scicos with a special emphasis on modeling and simulation tools. While it will provide useful information to experienced users it is designed to be accessible to beginning users from a variety of disciplines. Students and academic and industrial scientists and engineers should find it useful.The book is divided into two parts. The first part concerns Scilab and includes a tutorial covering the language features, the data structures and specialized functions for doing graphics, importing, exporting data and interfacing external routines. It also covers in detail Scilab numerical solvers for ordinary differential equations and differential-algebraic equations. Even though the emphasis is placed on modeling and simulation applications, this part provides a global view of Scilab. The second part is dedicated to modeling and simulation of dynamical systems in Scicos. This type of modeling tool is widely used in industry because it provides a means for constructing modular and reusable models. This part contains a detailed description of the editor and its usage, which is illustrated through numerous examples. All codes used in the book is made available to the reader.

Stephen L. Campbell is a professor of mathematics and a director of graduate programs at North Carolina State University, having published extensively on numerical methods and control. Jean-Philippe Chancelier is affiliated with CERMICS Ecole Nationale des Ponts et Chauss+¬es and is one of the original developers of Scilab. Ramine Nikoukhah is a director of research at INRIA (The French National Institute for Research in Computer Science and Control), senior member of IEEE, one of the original developers of Scilab, and is the creator of Scicos.

Part I Scilab

General Information

3

(6)

What Is Scilab?

3

(1)

How to Start?

4

(2)

Installation

4

(1)

First Steps

4

(1)

Line Editor

5

(1)

Documentation

6

(1)

Typical Usage

6

(1)

Scilab on the Web

7

(2)

Introduction to Scilab

9

(64)

Scilab Objects

11

(16)

Matrix Construction and Manipulation

12

(5)

Strings

17

(2)

Boolean Matrices

19

(1)

Polynomial Matrices

20

(1)

Sparse Matrices

21

(1)

Lists

22

(4)

Functions

26

(1)

Scilab Programming

27

(10)

Branching

28

(1)

Iterations

29

(2)

Scilab Functions

31

(4)

Debugging Programs

35

(2)

Input and Output Functions

37

(11)

Display of Variables

37

(1)

Formatted Input and Output

38

(2)

Input Output in Binary Mode

40

(2)

Accessing the Host System

42

(1)

Graphical User Interface

43

(5)

Scilab Graphics

48

(14)

Basic Graphing

48

(1)

Graphic Tour

49

(4)

Graphics Objects

53

(3)

Scilab Graphics and LATEX

56

(4)

Old Graphics Style

60

(2)

Interfacing

62

(11)

Linking Code

63

(3)

Writing an Interface

66

(3)

Dynamic Loading

69

(4)

Modeling and Simulation in Scilab

73

(34)

Types of Models

73

(5)

Ordinary Differential Equations

73

(1)

Boundary Value Problems

74

(1)

Difference Equations

75

(1)

Differential Algebraic Equations

76

(1)

Hybrid Systems

77

(1)

Simulation Tools

78

(29)

Ordinary Differential Equations

78

(12)

Boundary Value Problems

90

(5)

Difference Equations

95

(3)

Differential Algebraic Equations

98

(2)

Hybrid Systems

100

(7)

Optimization

107

(18)

Comments on Optimization and Solving Nonlinear Equations

107

(1)

General Optimization

108

(4)

Solving Nonlinear Equations

112

(1)

Nonlinear Least Squares

113

(4)

Parameter Fitting

117

(2)

Linear and Quadratic Programming

119

(1)

Linear Programs

119

(1)

Quadratic Programs

120

(1)

Semidefinite Programs

120

(1)

Differentiation Utilities

120

(5)

Higher Derivatives

122

(3)

Examples

125

(34)

Modeling and Simulation of an N-Link Pendulum

125

(10)

Equations of Motion of the N-Link Pendulum

126

(4)

Generated Code and Simulation

130

(3)

Maple Code

133

(2)

Modeling and Simulation of a Car

135

(7)

Basic Model

135

(1)

Equations of Motion

136

(2)

Simulation Model

138

(1)

Scilab Implementation

139

(2)

Simulation Result

141

(1)

Open-Loop Control to Swing Up a Pendulum

142

(5)

Model

142

(1)

Control Problem Formulation

142

(1)

Optimization Problem

143

(2)

Implementation in Scilab

145

(2)

Parameter Fitting and Implicit Models

147

(12)

Mathematical Model

148

(1)

Scilab Implementation

148

(11)

Part II Scicos

Introduction

159

(4)

Getting Started

163

(16)

Construction of a Simple Diagram

163

(6)

Running Scicos

163

(1)

Editing a Model

163

(2)

Diagram Simulation

165

(1)

Changing Block Parameters

166

(3)

Symbolic Parameters and Context

169

(4)

Hierarchy

173

(2)

Placing a Super Block in a Diagram

173

(1)

Editing a Super Block

174

(1)

Save and Load

175

(1)

Scicos File Formats

175

(1)

Super Block and Palette

176

(1)

Synchronism and Special Blocks

176

(3)

Scicos Formalism

179

(10)

Activation Signal

179

(3)

Block Activation

179

(2)

Activation Generation

181

(1)

Inheritance

182

(1)

Always Active Blocks

183

(1)

Constant Blocks

184

(1)

Conditional Blocks

184

(5)

Scicos Blocks

189

(20)

Block Behavior

189

(3)

External Activation

189

(2)

Always Activation

191

(1)

Internal Zero-Crossing

192

(1)

Blocks Inside Palettes

192

(1)

Modifying Block Parameters

193

(1)

Super Block and Scifunc

193

(1)

Super Blocks

193

(1)

Scifunc

194

(1)

Constructing New Basic Blocks

194

(13)

Interfacing Function

195

(2)

Computational Function

197

(10)

Saving New Blocks

207

(1)

Constructing and Loading a New Palette

207

(2)

Examples

209

(18)

Predator Prey Model

209

(1)

Control Application

210

(3)

Signal Processing Application

213

(3)

Queuing Systems

216

(2)

Neuroscience Application

218

(2)

A Fluid Model of TCP-Like Behavior

220

(1)

Interactive GUI

221

(6)

Batch Processing in Scilab

227

(26)

Piloting Scicos via Scilab Commands

227

(6)

Function scicosim

228

(4)

Function scicos_simulate

232

(1)

Data Sharing

233

(4)

Context Variables

234

(1)

Input/Output Files

234

(2)

Global Variables

236

(1)

Examples

237

(6)

Steady-State Solution and Linearization

243

(10)

Scilab Function steadycos

247

(1)

Scilab Function lincos

248

(5)

Code Generation

253

(14)

Code Generation Procedure

253

(4)

Limitations

257

(1)

Continuous-Time Activation

257

(1)

Synchronicism

258

(1)

A Look Inside

258

(2)

Some Pitfalls

260

(3)

Applications

263

(4)

Debugging

267

(6)

Error Messages

267

(2)

Block Errors

267

(1)

Errors During Numerical Integration

268

(1)

Other Errors

269

(1)

Debugging Tools

269

(1)

Examples

270

(3)

Log File

271

(1)

Animation

271

(2)

Implicit Scicos and Modelica

273

(8)

Introduction

273

(2)

Internally Implicit Blocks

275

(1)

Implicit Blocks

275

(2)

Scicos Editor

276

(1)

Scicos Compiler

276

(1)

Block Construction

276

(1)

Example

277

(4)

A. Inside Scicos

281

(12)

Scicos Editor

281

(5)

Main Editor Function

281

(2)

Structure of scs_m

283

(3)

Scicos Complier

286

(5)

First Compilation Stage

286

(1)

Second Compilation Stage

287

(1)

Structure of %cpr

287

(3)

Partial Compilation

290

(1)

Scicos Simulator

291

(2)

B. Scicos Blocks of Type 5

293

(14)

Type 5 Block for the Bouncing Ball Example

293

(1)

Animation Block for the Cart Pendulum Example

294

(5)

C Animation Program for the Car Example

299

(2)

D Extraction Program for the LATEX Graphic Example

301

(2)

E Maple Code Used for Modeling the N-Link Pendulum

303

(4)

References

307

(2)

Index

309

What is included with this book?

The New copy of this book will include any supplemental materials advertised. Please check the title of the book to determine if it should include any access cards, study guides, lab manuals, CDs, etc.

The Used, Rental and eBook copies of this book are not guaranteed to include any supplemental materials. Typically, only the book itself is included. This is true even if the title states it includes any access cards, study guides, lab manuals, CDs, etc.