Lecture: MATLAB Chapter 1 Introduction Dr. Khalid Kaabneh, Dr. Nidal Youssef

Introduction to MATLAB technical computing environment for numeric computation and visualization. MATLAB is an interactive matrix based system for scientific and engineering numeric computation and visualization. You can solve complex numerical problems in a fraction of the time required with a programming language such as Fortran or C The name MATLAB is derived from MATrix LABoratory Dr. Khalid Kaabneh, Dr. Nidal Youssef

Dr. Khalid Kaabneh, Dr. Nidal Youssef What is Matlab? Matlab is basically a high level language which has many specialized toolboxes for making things easier for us How high? Assembly High Level Languages such as C, Pascal etc. Matlab Dr. Khalid Kaabneh, Dr. Nidal Youssef

What are we interested in? Matlab is too broad for our purposes in this course. The features we are going to require is Matlab Command Line m-files functions mat-files Command execution like DOS command window Series of Matlab commands Input Output capability Data storage/ loading Dr. Khalid Kaabneh, Dr. Nidal Youssef

Dr. Khalid Kaabneh, Dr. Nidal Youssef Working Memory Command Window Command History Dr. Khalid Kaabneh, Dr. Nidal Youssef

Dr. Khalid Kaabneh, Dr. Nidal Youssef Variables No need for types. i.e., All variables are created with double precision unless specified and they are matrices. After these statements, the variables are 1x1 matrices with double precision int a; double b; float c; Example: >>x=5; >>x1=2; Dr. Khalid Kaabneh, Dr. Nidal Youssef

Dr. Khalid Kaabneh, Dr. Nidal Youssef Single Values The value of two variables can be added together, and the result displayed… >> A = 10 >> A + A …or the result can be stored in another variable >> B = A + A The value of the variable is accessed through it’s name..... Adding A to A adds the values in the variable A (here 10) therefore the result is 20 the result can be stored in a new variable, B, which you can see now has the value 20 Dr. Khalid Kaabneh, Dr. Nidal Youssef 7 7

Dr. Khalid Kaabneh, Dr. Nidal Youssef Single Values Can not do an assignment?? >> 15 = A Error>>>> …or the result can be an arithmetic operation >> A = 4 + 2 A = 6 The value of the variable is accessed through it’s name..... Adding A to A adds the values in the variable A (here 10) therefore the result is 20 the result can be stored in a new variable, B, which you can see now has the value 20 Dr. Khalid Kaabneh, Dr. Nidal Youssef 8 8

Dr. Khalid Kaabneh, Dr. Nidal Youssef Single Values If a variable in the working memory, then we Can do this: >> A = 32 A = 32 >> A = A + 18 … The value of the variable is accessed through it’s name..... Adding A to A adds the values in the variable A (here 10) therefore the result is 20 the result can be stored in a new variable, B, which you can see now has the value 20 Dr. Khalid Kaabneh, Dr. Nidal Youssef 9 9

Clear clear command will clear all variables. clear variablename clears out a particular variable Who will list the variables you have.

Number format >> format long >> 2 * sin(1.4) ans = 1.970899459976920 >> pi 3.141592653589793 >> format short 1.9709 3.1416

>> format loose >> 2^7 ans = 128 >> format compact

Dr. Khalid Kaabneh, Dr. Nidal Youssef Expressions in MATLAB Dr. Khalid Kaabneh, Dr. Nidal Youssef 13

Dr. Khalid Kaabneh, Dr. Nidal Youssef Expressions in MATLAB Operators usual set of arithmetic operators + - * / ^ a few special ones, e.g., *. /. \ usual set of logical operators: & | ~ Functions large library of built-in functions (e.q. sqrt, abs, sin) e.g., >> x = sqrt(a); Dr. Khalid Kaabneh, Dr. Nidal Youssef

Dr. Khalid Kaabneh, Dr. Nidal Youssef MatLab Operators >> 1 + 3 ans= 4 >> 3 * 4 12 >> 7 / 3 ans= 2.333 >> 7 ^ 3 343 Dr. Khalid Kaabneh, Dr. Nidal Youssef

assignment of variables ans = 5 >> a*b 6 Dr. Khalid Kaabneh, Dr. Nidal Youssef

Relational Operators <, <=, >, >=, ==, ~= compare corresponding elements of arrays with same dimensions if one is scalar, one is not, the scalar is compared with each element result is, element by element, 1 or 0

Relational Operators <, <=, >, >=, ==, ~= compare corresponding elements of arrays with same dimensions if one is scalar, one is not, the scalar is compared with each element result is element by element 1 or 0 » a = [2 3] a = 2 3 » b=[4,5] b = 4 5 » a > b ans = 0 0 » b > a ans = 1 1 » a > 2 ans = 0 1

Useful built-in functions save rand zeros min max load Remember to use the Matlab help command if you get stuck