Numerical Methods for Civil EngineersNumerical Methods for Civil Engineers

Welcome to

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Instructor: Mongkol JIRAVACHARADETInstructor: Mongkol JIRAVACHARADET

School of Civil Engineering

Institute of Engineering

Suranaree University of Technology

Lecture 1 -MATLAB

Introduction

References

Numerical Methods For Engineers with Personal Computer Applications,

(Third Edition) by Chapra, S.C. and R.P. Canale, McGraw-Hill, 1998

Numerical Methods with MATLAB : Implementations and Applications,

Gerald W. Recktenwald, Prentice-Hall, 2000

The Matlab 7 Handbook , Mathwork Inc.

KEEP THESE BOOKS! They are excellent career references

(at least for a while)

An Introduction to Numerical Methods : A MATLAB Approach,

Abdelwahab Kharab and Ronald B. Guenther, Chapman & Hall/CRC, 2002

Numerical Methods using MATLAB,

John H. Mathews and Kurtis D. Fink, Prentice-Hall, 2004

Topics Covered

• Introduction to Matlab

• Approximations and Errors

• Roots of Equations

• Linear Systems

• Curve Fitting

• Interpolation

• Numerical Integration

• Ordinary Differential Equations

• Optimization

Conduct of Course

Homework/Projects/Quizzes 30 %

Midterm Exam 30 %

Final Exam 40 %

Grading Policy

100 - 90

Final Score Grade

A

89 - 85 B+

84 - 80 B

79 - 75 C+

74 - 70 C

69 - 65 D+

64 - 60 D

59 - 0 F

WARNINGS !!!

1) Participation expected, check by quizzes

2) Study in groups but submit work on your own

3) No Copying of Matlab code

4) Submit Homework at the beginning of class

5) Late homework with penalty 30%

6) No make up quizzes or exams

MATLABThe Language of Technical Computing

The latest version Matlab 7.3 R2006b

www.mathworks.com

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MATLAB = MATrix LABoratory

- Math and computation

- Algorithm development

- Modeling, Simulation, and Prototyping

- Many toolboxes for solving problems:

Control System Toolbox

Signal Processing Toolbox

System Identification Toolbox

Neural Network Toolbox

Statistics Toolbox

Optimization Toolbox

Partial Diff. Equation Toolbox

Symbolic Math Toolbox

- Data analysis, exploration, and visualization

- Scientific and Engineering Graphics

http://www.math.utah.edu/lab/ms/matlab/matlab.html

http://www.mathworks.com/

http://www.math.mtu.edu/~msgocken/intro/intro.html

MATLAB Educational Sites

http://www.eece.maine.edu/mm/matweb.html

- Getting started

- Basic Arithmetic

- Built-in Functions

- Built-in Variables

MATLAB 1

The MATLAB System

The MATLAB system consists of five main parts:

Development Environment: set of tools and facilities that help you use MATLAB

functions and files. Many of these tools are graphical user interfaces. It includes the

MATLAB desktop and Command Window, a command history, an editor and

dedugger, and browsers for viewing help, the workspace, files, and the search path.

The MALAB Mathematical Function Library: a vast collection of computational

algorithms.

The MATLAB Language: This is a high-level matrix/array language with control

flow statements, functions, data structures, input/output, and objected-oriented

programming features.

Graphics: MATLAB has extensive facilities 2-D and 3-D data visualization,

animation, and presentation graphics.

The MATLAB Application Program Interface (API): allows you to write C and

Fortran programs that interact with MATLAB.

Getting Started

MATLAB Desktop

Getting Started

Command Window

Command prompt >> DEMO

Getting Started

Editor/Debugger

Basic Arithmetic

Last-line editing

Calculator functions work as you'd expect:

>>(1+4)*3

ans =

15

+ and - are addition, / is division, * is multiplication, ^ is an exponent.

>> 5*5*5

>> 5^(-2.5)

>> 3*(23+14.7-4/6)/3.5

Up Arrow

>> 2 + 6 - 4

ans =

4

The value in ans can be recalled:

>> ans/2

ans = 2

Assign value to a variable:

>> a = 5

>> b = 6

>> c = b/a

>> a=2;

>> A=3;

>> 2*a

>> 2*A

Upper & Lower Case

sin(x), cos(x), tan(x),

sqrt(x), log(x), log10(x),

asin(x), acos(x), atan(x)

Built-in Functions

>> sin(pi/4)

ans =

0.7071

>> pi

ans =

3.1416

The output of each command can be suppress by using semicolon ;

>> x = 5;

>> y = sqrt(59);

>> z = log(y) + x^0.25

z =

3.5341

The commas allow more than one commandon a line:

>> a = 5; b = sin(a), c = sinh(a)

b =

-0.9589

c =

74.2099

MATLAB Variables is created whenever it appears

on the left-hand of “ = “

>> t = 5;

>> t = t + 2

t =

7

Format

>> pi

>> format long

>> pi

>> format short

>> format bank

>> format short e

>> format long e

>> format compact

>> format loose

>> format

Any variable appearing on the right-hand side of

“ = “ must already be defined.

>> x = 2*z

??? Undefined function or variable ‘z’

Use long variable names is better to remember

and understandable for others

>> radius = 5.2;

>> area = pi*radius^2;

>> who

>> whos

>> clear

Built-in Variables

Use by MATLAB, Should not be assigned to other values

Variable Meaning

ans value of an expression when not assigned to variable

eps floating-point precision

i, j unit imaginary numbers, i = j =

pi π = 3.14159265 . . .

realmax largest positive floating-point number

realmin smallest positive floating-point number

Inf ∞, a number larger than realmax, result of 1/0

NaN not a number (0/0)

1−

>> x = 0;

>> 5/x

>> x/x

>> help log

>> lookfor cosineOn-line Help: