matlab introduction.pptx

7/27/2019 MATLAB Introduction.pptx

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Sana Zahid


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Today's Topics

Books for MATLAB

Introduction to MATLAB


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MATLAB BOOKS


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Our main book

INTRODUCTION TO MATLAB 7

FOR ENGINEERS

byWILLIAM J. PALM III


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MATLAB - developed by Math Works Inc.

http://www.mathworks.com

MATLAB - acronym for MATrix LABoratory

Matrices and arrays - the heart ofMATLAB

Offers programming features - similar to other

languages

Offers GUI tools

Introduction to MATLAB


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Provides a variety of graphic output displays:

linear

log-log

semilog

polar

bar chart, and

contour plots

2-D and 3-D views


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Provides extensive numerical resources

Over 200 reliable, accurate mathematical

subprograms

The subprograms provide solutions to broad range of

mathematical problems including:

matrix algebra

complex arithmetic

differential equations nonlinear systems, and

many special functions


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many special functions available in all operating

systems: DOS

Windows9.x/NT

Unix

Macintosh

Same syntax for all platforms

Open system environment - access to source code

Allows - to mix MATLAB with FORTRAN or C

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Default Appearance


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Simple MathScalar arithmetic operations

Exponentiation ^

Multiplication *

Right division /

Left division \

Addition +Subtraction -


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Simple Math 2+2.5+106

ans =

110.5000

4*25 + 2^3

ans =

108


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Order of Precedence

[{()}] from innermost

^ from left to right* & / from left to right

+ & - from left to right


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MATLAB Variables D = 2

D =

2

v = 3

v =

3


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MATLAB Variables rho = 1000; mu = 0.001;

NRe = D*v*rho/mu

NRe =

6000000


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MATLAB Workspace

To recall the variable

D

D =

2

Use arrow keys for scrolling

through previous commands


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MATLAB Workspace

List of variables in the workspace

who

Your variables are:

D NRe mu rho v


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Variable Naming RulesVariable names are case sensitive. For exampleNRe

and nRe are different MATLAB variables

Variable name can contain upto 31 characters.

Start with a letter, followed by letters, numbers or

underscores.

For example:NRe_2_the_power2by3


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Special variables

ans Default variable name used for resuts

pi Value of p

inf Stands for infinity (e.g., 1/0)

NaN Stands for Not-a-Number (e.g., 0/0)

i, j i = j =-1


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To clear a variable who

Your variables are:

D ans rho

NRe mu v

clear D

who

Your variables are:

NRe ans mu rho v


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To clear variables who

Your variables are:

NRe ans mu rho v

clear

who


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Complex Numbers

i

ans =

0 + 1.0000i

c1 = 2+3i

c1 =

2.0000 + 3.0000i


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Mathematical Functions

x=sqrt(2)/2

x =

0.7071

y=sin(x)

y =

0.6496


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Built-in Functions

Trigonometric

functionssin, cos, tan, sin, acos, atan,

sinh, cosh, tanh, asinh,

acosh, atanh, csc, sec, cot,

acsc, Exponential

functions

exp, log, log10, sqrt

Complex

functionsabs, angle, imag, real, conj

Rounding and

Remainder

functions

floor, ceil, round, sign


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Array Operations

x = [1 2 3 4 5 6 7 8 9 10]

x =

1 2 3 4 5 6 7 8 9 10

a = 1:2:10

a =

1 3 5 7 9


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Array Operations

y = sin(x)

y =

Columns 1 through 7

0.8415 0.9093 0.1411 -0.7568 -0.9589 -0.2794

0.6570

Columns 8 through 10

0.9894 0.4121 -0.5440


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Array Addressing

y(3)

ans =

0.1411

y(1:5)

ans =

0.8415 0.9093 0.1411 -0.7568 -0.9589


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Array Orientation

z = [1; 2; 3; 4]

z =

1

23

4

z'

ans =

1 2 3 4


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Array Manipulation

A = [1 2; 3 4; 5 6]

A =

1 2

3 45 6

B = [1 2 3; 4 5 6];

A+B??? Error using ==> +

Matrix dimensions must agree.


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Array Manipulation

A*B

ans =

9 12 15

19 26 3329 40 51


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Significance of. clear A = [1 2; 3 4];

B = [1 1; 2 2];

A.*B

ans =

1 2

6 8


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Significance of. A./B

ans =

1.0000 2.0000

1.5000 2.0000

A/B

Warning: Matrix is singular to working precision.

ans =

Inf Inf

Inf Inf


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Matrix Operations [A B]

ans =

1 2 1 1

3 4 2 2

ans-1

ans =

0 1 0 0

2 3 1 1


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Matrix Operations C = [A B]

C =

1 2 1 1

3 4 2 2

C(1,:)

ans =

1 2 1 1

C(:,2)

ans =

2

4

C(:,2:end)

ans =

2 1 1

4 2 2


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Matrix Functions size(C)

ans =

2 4

det(A)

ans =

-2

A

A =

1 2

3 4

inv(A)

ans =

-2.0000 1.0000

1.5000 -0.5000


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Matrix Functions & Arrays

Some functions: det, inv, diag, triu, tril,rank, eig, size,

Other such arrays:ones(n), ones(r, c)

zeros(n), zeros(r, c)

rand(n), rand(r,c)eye(n), eye(r,c)


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29. Oktober 2013 /

matlab introduction.pptx

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