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= MATLABMathematics + Laboratory

+

Dan Ophir, Ph.D.

Cell.: 052-551359

e-Mail: comp_ophir@yahoo.com

Civil Engineering

=

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Requirements

Tests:

1. Intermediate,

2. Final.

Exercises in diskettes

1. .rtf format (Office);

2. .m, .mdl, .fig (Matlab)

50% Lectures + 40% Exercises

Note = Tests + Exercises

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Students

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Files

1. .m --- Script

2. .mat --- Workspace

3. .mdl --- Block program – Model (Simulink)

User’s:

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Conventions

1) > - pressing on a menu, sub-menu, button

2) blue – link

3) red – a reserved word.

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Mode of Interaction

Interpreter

Compiler

Interactive

Batch:

Script

Program

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MATLAB - Potential

MATLAB.EXE.lnk

Type: Demo

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Demo

MATLAB>Matrices>graphs and matrices

MATLAB>Numerics>2D-solutions

MATLAB>Numerics>Command line demos>Run Command line demos >function plot

MATLAB>Visualization>3D plots of comples functions>Run 3D plots of> Cube root

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Demo (2-cont.)

MATLAB>Language/Graphics>3d surface plots> Run 3D surface plots>color map

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Work Environment

Desktop

FilesWork- Space

Windows

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Windows

User’s:

1. Script .m

2. Module .mdl

3. Figure .fig

System’s:

1. Commands (history)

2. Variables

3. Help Window

4. Launch Pad

5. Workspace (variables)

6. Array Editor

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Getting Starting

MATLAB: Command Window

First commands:

1. helpwin – list of all .m files (scripts) included in the path (described in a help window) > tips (>See also, >Back, >Forward)

2. help - a help in the command window.

3. help debug – a help of special topics or command.

lookfor conversion

which fprintf

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Interactive Calculation

Command window:

x=5;

y=x+2;

disp(y);

files .mat for workspace saving.

MATLAB.mat – default file name

who – the local variables values

whos – the local variables data structure

use: save / load –

to treat with workspace file

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M-File Editor/Debugger window

1. Command window: setpath

2. Command window: open fibonaci.m file

3. Command window: fibonaci

Input:

Output:

1. Command window: Fibonacci series

2. Figure No. 1

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Fibonnacci

1 1 2 3 5 8 13 21…

Converges to the golden ratio.

A BC

AB : CB = CB : AC

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Golden Ratio

Parthenon

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Simulink window

First step:

1) menu:file>new>model

2) or: >open>browsing .mdl

gives the model specifications.

3) model - icon

Second step:

1) menu: file>open

2) Browsing for .mdl

C:\MATLAB_5\my_examples\mdl\MDL\Simple\INTEGRAL.MDL

Modeling Programming

Third step: (Integral window)

1. menu: simulation>start

2. Input & Integration windindows

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MATLAB as a Language

Language :

Syntax,

Semantics

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Language Components

script – function: f(a,b)

command: x=y+5

variable: myBook_1

operator: + *

constant: 3.27

special symbol: % , ; “ ( )

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Operations (operators)

operation symbol example

Addition + 3+2

Subtraction - 54.4 –25.3

Multiplication * 3.15 * 6

Division / or \ 23.4/8

Exponentiation ^ 3^4

helpwin>matlab\ops>*

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Variables

Naming rules:

1. letters, digits, _

2. Case sensitive

3. Starting with a letter

Reserved World List (17)

for end if while function return elseif case otherwise switch continue else try catch global persistent break

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MATLAB special

variables

Special Variables

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Control Flow keywords

% if - Conditionally execute statements.

% else - IF statement condition.

% elseif - IF statement condition.

% end - Terminate scope of FOR, WHILE, SWITCH and IF statements.

% for - Repeat statements a specific number of times.

% while - Repeat statements an indefinite number of times.

% break - Terminate execution of WHILE or FOR loop.

help>manual>control flow

help>else

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Functions Library

Trigonometric : sin, cot

Exponential : log, exp, ^, sqrt

Complex : conj, real

Rounding and remainder: fix, floor, mod

Coordinate Transformation: carth2sph,pol2cart

Number Theoretic: factor, isprime, gcd

Specialized: besselj, legendre

helpwin> matlab\elfun (topics elem. func) > tan

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Function Syntax

Example:

function [mean] = avg(x,n)

mean = sum(x)/n;

function [list of output arguments ] = name (input-arg.)

commands…

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Command

Command: collection of the following entities:

variables, constants, calling functions, keywords (reserved words) and operators.

Examples: x=23+10*sin(0.3);

x

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Program

Program: A collection of commands with some significance.

>> % fibonnaci - sequence

>> b(1)=1; b(2)=1;

>> for I=3:5,

b(I)=b(I-1)+b(I-2);

end

>> b

>> who

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Example: FOR, matrix

Command:

>> for i=1:5,

for j=1:4,

a(i,j)=i+j;

end

end

>> a

Output:

2 3 4 5

3 4 5 6

4 5 6 7

5 6 7 8

6 7 8 9

basewords:

loop, matrix, index

operators: >> : , () ;row column

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Simple for, if

for I=1:5

I

end

1 2 3 4 5

Code: Output:

I=1; J=2; X=5; X=6;

if x==5

I

else

J

end

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FAQ

Frequently Asked Questions שאלות שכיחות

>> If

for …

Previous command

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Language Manual

MANUAL.M

MANUAL.M

help manual

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Script, Program, Function

Script, Program, Function :

A collection of commands enclosed between two special commands (module) and having a special task.

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example 1(list)

Choose 8 Reserved words and explain their function in MATLAB and give examples of their usage.

Use the help features of MATLAB and the manual.m file.

Choose 5 operators not given in the lecture and explain their function

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example 2 (Pitagoras)

Input: Two perpendicular sides a,b of a right-angled triangle,

Output: The length of the opposite side c.

Do: To write commands to compute c.

b

a

c

c2 = a2 + b2

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Simple Script – Sum_Arr

1. a=[1 2 3];

2. n=3;

3. % function f=sum(a,n)

4. % Computing the sum of the elements of an array

5. sum1=0;

6. for i=1:n,

7. sum1=sum1+a(i);

8. end

9. f=sum1;

10. s=sprintf('sum:%d',sum1);

11. disp(s);

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Fibonacci Script (recursive)

1. % fibonaci.m (recusive algorithm)

2. %A script to calculate Fibonacci numbers

3. %first described by Leonardo of Pisa

4. f=[1 1]; n=1;

5. while f(n) + f(n+1) <100

6. f(n+2)=f(n)+f(n+1)

7. n=n+1;

8. end

 

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example 3 (primes)

1. Write a script/function myPrime to print all the prime numbers less than n;

2. Take n=100.

3. Compare the results with those received by using the MATLAB original function.

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Line 2D

MATLAB5.EXE.lnk

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example 4: Triangle

Draw (in the .m file) a triangle ,whose vertices are at the points: (5,5), (0,10), (10,10)

) משולש שקודקודיו m.שרטט (קובץ )10,10),(0,10),(5,5(בנקודות הבאות: