curso de introduccion al matlab2

7/28/2019 Curso de Introduccion Al Matlab2

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Introduction to MATLAB

Yunkai Liu

Assistant Professor

Computer Science Department

University of South Dakota


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What is MATLAB?

MATLAB (MATrix LABoratory)

MATLAB is developed by The MathWorks, Inc. MATLAB is a high-level technical computing

language and interactive environment for

algorithm development, data visualization, data

analysis, and numeric computation.

MATLAB can be install on Unix, Windows and

Mac.


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History of MATLAB

Ancestral software to MATLAB

Fortran subroutines for solving linear (LINPACK)and eigenvalue (EISPACK) problems

Developed primarily by Cleve Moler in the 1970s


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History of MATLAB

In 1970, Cleve Moler, the chairman of the

computer science department at University ofNew Mexico, designed MATLAB to give his

students to access LINPACK and EISPACK

without requiring knowledge of Fortran


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History of MATLAB, cont: 2

It soon spread to other universities and found

a strong audience within the appliedmathematics community.

In1984, Jack Little, Cleve Moler and Steve

Bangert rewrote MATLAB in C with more

functionality (such as plotting routines).


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MathWorks Product Overview


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Distributed Computing @ matlab


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MATLAB

MATLAB is a high-level language and

interactive environment that enablesyou to perform computationally intensive

tasks faster than with traditional

programming languages such as C, C++,

and Fortran.


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Simulink- Simulation and Model-Based Design

Simulink is a platform for multidomain

simulation and Model-Based Design fordynamic systems. It provides an

interactive graphical environment and a

customizable set of block libraries, andcan be extended for specialized

applications.


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Statistics Toolbox 5.1

Apply statistical algorithms and probability models

Key Features Calculation and fitting of probability distributions

Linear and nonlinear modeling

Multivariate statistics

Descriptive statistics

Analysis of variance (ANOVA)

Hypothesis testing

Industrial statistics (Statistical Process Control, Design ofExperiments)

Statistical plotting and data visualization


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Bioinformatics Toolbox 2.2

Read, analyze, and visualize genomic, proteomic, andmicroarray data

Key Features

Genomic, proteomic, and gene expression file formats

Internet database access

Functions for pairwise and multiple sequence alignment

Sequence analysis tools

Phylogenetic tree analysis tools Capabilities for microarray data analysis and visualization

Support for mass spectrometry preprocessing and analysis

Statistical learning functionality


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SimBiology 1

Model, design, and simulate biochemical pathways

Key Features Access to all functions via the command line and a graphical

user interface

Stochastic, stiff deterministic, and nonstiff deterministic solvers

Model components, including species, parameters, kinetic laws,

reactions, algebraic rules, and units Project files that store models with simulation settings and user-

defined plot types


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Strengths of MATLAB

MATLAB is relatively easy to learn.

MATLAB code is optimized to be relativelyquick when performing matrix operations.

MATLAB may behave like a calculator or asa programming language.

MATLAB is interpreted, errors are easier tofix.

Although primarily procedural, MATLAB doeshave some object-oriented elements.


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Other Features

2-D and 3-D graphics functions for

visualizing data Tools for building custom graphical user

interfaces

Functions for integrating MATLAB based

algorithms with external applications andlanguages, such as C, C++, Fortran, Java,

COM, and Microsoft Excel


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Weaknesses of MATLAB

MATLAB is NOT a general purpose

programming language. MATLAB is an interpreted language (making

it for the most part slower than a compiled

language such as C++).

MATLAB is designed for scientificcomputation and is not suitable for some

things (such as parsing text).


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The Latest Update

The latest version of MATLAB is 7.1.

Release 14 with Service Pack 3 (R14SP3),launched on September 1, 2005, provides

updates to MATLAB, Simulink, and 75 other

products.


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Licenses

MATLAB @ home Standard edition

Available for roughly two thousand dollars Student edition

Available for roughly one hundred dollars.

Some limitations, such as the allowable size of a matrix orsome toolboxes.

MATLAB @USD

Art & Science Building 16 B

MATLAB @ SDSU

Solberg 1st floor


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References

http://www.mathworks.com/products/matlab/i

ndex.html http://www.ccs.neu.edu/home/wmason/

Mastering MATLAB 7. Duane C. Hanselman,

Bruce L. Littlefield. Prentice Hall, 2004.

MATLAB: An Introduction with Applications.

Amos Gilat. Wiley, 2003.
http://www.mathworks.com/products/matlab/index.htmlhttp://www.mathworks.com/products/matlab/index.htmlhttp://www.ccs.neu.edu/home/wmason/http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Duane%20C.%20Hanselman&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Bruce%20L.%20Littlefield&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Amos%20%20Gilat&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Amos%20%20Gilat&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Bruce%20L.%20Littlefield&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.amazon.com/exec/obidos/search-handle-url/index=books&field-author-exact=Duane%20C.%20Hanselman&rank=-relevance%2C%2Bavailability%2C-daterank/102-9677697-2559334http://www.ccs.neu.edu/home/wmason/http://www.mathworks.com/products/matlab/index.htmlhttp://www.mathworks.com/products/matlab/index.html


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Components of MATLAB Interface

Workspace

Current Directory Command History

Command Window


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Interactive Calculations

Matlab is interactive, no need to declare variables

>> 2+3*4/2 >> a=5e-2; b=1; a+b

Most elementary functions and constants are already

defined >> cos(pi)

>> abs(1+i)

>> sin(pi)


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Variable and Memory Management

Matlab uses double precision

>> format long (15 fixed point format)>> format compact (5 fixed point format)

All variables are shown with

>> who lists the variables currently in the workspace.>> whos whos is similar to who, but also gives size and storage information

Variables can be stored on file>> save filename>> clear>> load filename


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The Help System

Search for appropriate function

>> lookfor keyword

Rapid help with syntax and function definition

>> help function

An advanced hyperlinked help system is launched by>> helpdesk

Complete manuals

http://www.mathworks.com/access/helpdesk/help/techdoc/
http://www.mathworks.com/access/helpdesk/help/techdoc/http://www.mathworks.com/access/helpdesk/help/techdoc/


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Vectors and Matrices

Vectors (arrays) are defined as

>> v = [1, 2, 4, 5]

>> w = [1; 2; 4; 5]

Matrices (2D arrays) defined similarly >> A = [1,2,3;4,-5,6;5,-6,7]


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Matrix Operators

All common operators are overloaded >> v + 2

Common operators are available >> B = A >> A*B >> A+B

Note: Matlab is case-sensitive

A and a are two different variables


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Indexing Matrices

Indexing using parentheses

>> A(2,3)

Index submatrices using vectorsof row and column indices

>> A([2 3],[1 2])

Ordering of indices is important!>> B=[A(3,2),A(3,1);A(2,2), A(2,1)]

>> B=A([3 2],[2 1])


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Indexing Matrices

Index complete row or column using

the colon operator

>> A(1,:)

Can also add limit index range

>> A(1:2,:)

>> A([1 2],:)

General notation for colon operator

>> v=1:5

>> w=1:2:5


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Matrix Functions

Many elementary matrices predefined >> help elmat; >> I=eye(3)

Elementary functions are often overloaded >> help elmat >> sin(A)

Specialized matrix functions and operators >> As=sqrtm(A) >> As^2 >> A.*A Note: in general, . is elementwise operation


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Numerical Linear Algebra

Basic numerical linear algebra >> z=[1;2;3]; x=inv(A)*z

>> x=A\zMany standard functions predefined >> det(A) -- determinant >> rank(A) matrix rank >> eig(A)--Eigenvalues and eigenvectorsThe number of input/output arguments can often be varied >> [V,D]=eig(A)

[V,D] = EIG(X) produces a diagonal matrix D of eigenvalues and a

full matrix V whose columns are the corresponding eigenvectors

so that X*V = V*D.


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Graphics

Visualization of vector data is available

>> x=-pi:0.1:pi; y=sin(x);

>> plot(x,y) >> plot(x,y,s-) s means squre and means solid

>> xlabel(x); ylabel(y=sin(x));

Can change plot properties in Figure menu, or via handle

>> h=plot(x,y); set(h, LineWidth, 4);

Many other plot functions available

>> v=1:4; pie(v)


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Graphics

Three-dimensional graphics>> A = zeros(32);>> A(14:16,14:16) = ones(3);>> F=abs(fft2(A));FFT2 Two-dimensional discrete Fourier Transform. FFT2(X) returns the two-dimensional Fouriertransform of matrix X.If X is a vector, the result will have the same orientation.

>> mesh(F) MESH 3-D mesh surface.>> rotate3d on

Several other plot functions available>> surfl(F)

Can change lightning and material properties>> cameramenu>> material metal


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Graphics

Bitmap images can also be visualized

>> load mandrill

>> image(X); colormap(map)

>> axis image off


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MATLAB Scripts

Scripts are MATLAB commands stored in

text files. When you type the name of the

script file at the MATLAB prompt the

commands in the script file are executed as if

you had typed them in from the keyboard.

Scripts end with the extension .m Referred to as M-Files


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For Loops

Common to other programming languages

forvariable = expression

statement

...

statement

end


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Case statements

Syntax

switch switch_expr

case case_expr

statement,...,statement

case

{case_expr1,case_expr2,case_expr3,...}statement,...,statement ...

otherwise

statement,...,statement end


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E d

Another satisfied MATLAB user!

curso de introduccion al matlab2

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