MATLAB Lecture 5 School of Mathematical Sciences Xiamen University http∥gdjpkc.xmu.edu.cr MATLAB Lecture 5-Symbol computation 符号计算 Ref: Symbolic Math Toolbox-Getting Started Symbolic Math Toolbox-Using the Symbolic Math Toolbox These versions of the Symbolic Math Toolboxes are designed to work with MATLAB 6 or greater and Maple 8 data type数据类型 toolbox工具箱 symbol computation符号计算 symbolic object符号对象 numerical value数值 variable变量 represent表示 store存储 string(字符)串 expression表达式 equation方程 substitute代换,代入,替换 function函数 abstract抽象的 indeterminate不确定的 circulant matrⅸx循环矩阵 nested/ horner嵌套的 collecting合并(的) expand展开 factor因子 factoring因式分解 algebraic代数的 trigonometrIc三角(学)的,三角(法)的 恒等式 transform转换 simplification化简 ● Some funetions sym syms simple simplify collect expand horner factor *findsym double *eval Symbolic math Toolbox Y Symbolic Objects The symbolic Math Toolbox defines a new matlab data type called a symbolic object (See Programming and Data Types in the online MATLAB documentation for an introduction to MATLAB classes and objects. )Internally, a symbolic object is a data structure that stores a string representation of the symbol. The Symbolic Math Toolbox uses symbolic objects to represent symbolic variables, expressions, and matrices. The actual computations involving symbolic objects are performed primarily by maple, mathematical software developed by Waterloo Maple, Inc The following example illustrates the difference between a standard matlAB data type uch as double, and the corresponding symbolic object. The matlab command > sqrt(2) %returns a floating-point decimal numberMATLAB Lecture 5  School of Mathematical Sciences Xiamen University  http://gdjpkc.xmu.edu.cn  Lec5­1 MATLAB Lecture 5 – Symbol Computation 符号计算 Ref: Symbolic  Math Toolbox→Getting Started  Symbolic  Math Toolbox→Using  the  Symbolic  Math Toolbox  These versions of the Symbolic Math Toolboxes are designed to work with MATLAB 6 or greater and Maple 8.  l Vocabulary: data type 数据类型 toolbox  工具箱 symbol  符号 symbol computation  符号计算 symbolic object  符号对象 numerical value  数值 variable 变量 represent  表示 store 存储 string  （字符）串 expression  表达式 equation  方程 substitute 代换，代入，替换 function  函数 abstract  抽象的 indeterminate  不确定的 circulant matrix  循环矩阵 nested/horner 嵌套的 collecting  合并（的） expand  展开 factor 因子 factoring  因式分解 algebraic 代数的 trigonometric 三角（学）的，三角（法）的 identities  恒等式 transform  转换 simplification  化简 l Some functions sym syms  simple simplify  collect  expand  horner factor *findsym  *sum  *double *eval  l Symbolic Math Toolbox  ² Symbolic Objects The Symbolic Math Toolbox defines  a new MATLAB data  type called  a symbolic  object.  (See Programming and Data Types in the online MATLAB documentation for an introduction  to MATLAB classes and objects.) Internally, a symbolic object is a data structure that stores a string representation of the symbol. The Symbolic Math Toolbox  uses symbolic objects to  represent symbolic variables, expressions,  and matrices. The actual computations involving  symbolic objects are performed primarily  by  Maple, mathematical software developed by  Waterloo Maple, Inc.  The following example illustrates  the difference between a standard MATLAB data  type,  such as double, and the corresponding symbolic object. The MATLAB command  >> sqrt(2) %returns a floating­point decimal number:  ans =