Matlab
Programming
Huajun Wang
Department of Earth Sciences,
Zhejiang University
wanghj@zju.edu.cn
Jan 25,2012
References
• Product help (F1)
• http://www.mathworks.cn/ac
ademia/student_center/tutori
als/launchpad.html
Main content
I. introduction
II. syntax and command
III.M-file programming
IV. Advanced programming
Chap1.introduction
1.1
1.2
1.3
1.4
Matlab 's history
Main features of Matlab
Programming environment
Matlab Desktop (V2011b)
1.1 Matlab 's history
MATLAB =
MATrix (Matrices) &
LABoratory
1.1 Matlab 's history
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December 1996 First printing For MATLAB 5
May 1997 Second printing For MATLAB 5.1
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September 1998 Third printing For MATLAB 5.3
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September 2000 Fourth printing Revised for MATLAB 6 (Release 12)
June 2001 Online only Revised for MATLAB 6.1 (Release 12.1)
July 2002 Online only Revised for MATLAB 6.5 (Release 13)
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August 2002 Fifth printing Revised for MATLAB 6.5
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June 2004 Sixth printing Revised for MATLAB 7.0 (Release 14)
October 2004 Online only Revised for MATLAB 7.0.1 (Release 14SP1)
March 2005 Online only Revised for MATLAB 7.0.4 (Release 14SP2)
June 2005 Seventh printing Minor revision for MATLAB 7.0.4 (Release 14SP2)
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September 2005 Online only Minor revision for MATLAB 7.1 (Release 14SP3)
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March 2006 Online only Minor revision for MATLAB 7.2 (Release 2006a)
September 2006 Eighth printing Minor revision for MATLAB 7.3 (Release 2006b)
March 2007 Ninth printing Minor revision for MATLAB 7.4 (Release 2007a)
September 2007 Tenth printing Minor revision for MATLAB 7.5 (Release 2007b)
March 2008 Eleventh printing Minor revision for MATLAB 7.6 (Release 2008a)
October 2008 Twelfth printing Minor revision for MATLAB 7.7 (Release 2008b)
March 2009 Thirteenth printing Minor revision for MATLAB 7.8 (Release 2009a)
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September 2009 Fourteenth printing Minor revision for MATLAB 7.9 (Release 2009b)
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March 2010 Fifteenth printing Minor revision for MATLAB 7.10 (Release 2010a)
September 2010 Sixteenth printing Revised for MATLAB 7.11 (R2010b)
April 2011 Online only Revised for MATLAB 7.12 (R2011a)
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September 2011 Seventeenth printingRevised for MATLAB 7.13 (R2011b)
1.2 Main features of
Matlab
 High-level language for technical computing
 Development environment for managing code,
files, and data
 Interactive tools for iterative exploration, design,
and problem solving
 Mathematical functions for linear algebra,
statistics, Fourier analysis,
 filtering, optimization, and numerical integration
 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 and languages, such as C, C++,
Fortran, Java™, COM, and Microsoft® Excel®
1.3 Programming
environment
Core functionality as
compiled C-code, m-files
Additional functionality
in Toolboxes (m-files)
Interactive operation
8
1.4 Matlab
Desktop(V2011b)
Start matlab and see(demo)
1.4 Matlab
Desktop(V2011b)
Command History: View, search, copy, or execute statements you
previously entered in the Command Window
Command Window: Run MATLAB language statements.
Current Folder Browser: Vinew, open, and find files and file content.
Perform file management operations.
Editor: Create, edit, debug, and analyze files containing MATLAB
language statements.
Figures: Create, modify, view, and print figures generated with
MATLAB.
Comparison Tool: View line-by-line differences between two files.
Help Browser: View and search the documentation and demos for all
your MathWorks products.
Profiler: Improve the performance of your MATLAB code.
Variable Editor: View array contents in a table format and edit the
values.
Web Browser: View HTML and related files produced by MATLAB.
Workspace Browser: View and change the contents of the workspace.
Chap2. syntax
and command
2.1
2.2
2.3
2.4
2.5
Basic concept
Matrices & Arrays
Commonly used commands
Flow control
Graphics
2.1 Basic concept
1.Identifier
Name of functions or variables.
•
Require
Composed by letter, numerical and underline;
Not more than 31 characters;
Case sensitivity;
Can not start by numerical;
• Example
A，b , c8, d_f
2g,
h(k
2.1 Basic concept
2. Constant
pi
i
j
eps
Realmin
Realmax
Inf
NaN
3.14159265...
Imaginary unit
Same as i
Floating-point relative precision
Smallest floating-point number
Largest floating-point number
Infinity
Not-a-number
2.1 Basic concept
3.Variable
Just for storage the data.
4.Functions
Usually: the name of function is
composed by small letters.
2.1 Basic concept
5. Order of identifier Searches
a.
b.
c.
d.
e.
variable in current workspace
built-in variable
built-in m-file
m-file in current directory
m-file on search path
2.1 Basic concept
6. Operators
+ - * /
Relational operators
==
(equal to)
<
(less than)
>
(greater than)
to)
Logical operators
&
(and)
|
(or)
~
(not)
……
~=
<=
>=
(not equal)
(less than or equal to)
(greater than or equal
2.1 Basic concept
7. Expression
Variables, constants and
functions connected by the
operator.
a+b
c*f(a)
2.1 Basic concept
8. Statement
Value of the expression
assigned to a variable called
assign command statement;
<variable> = <expression >
a = zeros(2,2);
2.1 Basic concept
9. Comment & others
%
;
…
2.2 Matrices & Arrays
1.Matrices generate
Colon(:) & Brackets([])
ones, zeros, sparse
magic, randn
linspace,logspace
true,false
2.2 Matrices & Arrays
1.Matrices generate
Colon(:) Brackets([])
a = [1,2,3;4,5,6;7,8,9]
b = 1:2:10
2.2 Matrices & Arrays
2.Operators
+
*
/
\
^
'
( )
Addition
Subtraction
Matrices Multiplication
Matrices Division
Matrices Left division
Matrices Power
Complex conjugate transpose
Specify evaluation order
2.2 Matrices & Arrays
.*
./
.\
.^
.'
Element-by-element
Element-by-element
Element-by-element
Element-by-element
Unconjugated array
multiplication
division
left division
power
transpose
2.2 Matrices & Arrays
3. Other operate
size,length
isempty,any,all
diag, triu, tril
inv,det,svd,
……
2.2 Matrices & Arrays
4.Example
A=magic(3)
X=[1 3 5]'
b=A*X
2.3 Commonly used
commands
1.help, lookfor
2.Who,whos,disp
3.Save,load
4.clc, clear
5.cd,dir,pwd,path,!(system)
6.input,ginput
2.4 Flow control
1.Conditional Control
if, else, switch
% Generate a random number
a = randi(100, 1);
% If it is even, divide by 2
if rem(a, 2) == 0
disp('a is even')
b = a/2;
end
2.4 Flow control
1.Conditional Control
if, else, switch
a = randi(100, 1);
if a < 30
disp('small')
elseif a < 80
disp('medium')
else
disp('large')
end
2.4 Flow control
1.Conditional Control
if, else, switch
[dayNum, dayString] = weekday(date, 'long', 'en_US');
witch dayString
case 'Monday'
disp('Start of the work week')
case 'Tuesday'
disp('Day 2')
case 'Wednesday'
disp('Day 3')
case 'Thursday'
disp('Day 4')
case 'Friday'
disp('Last day of the work week')
otherwise
disp('Weekend!')
end
2.4 Flow control
2.loop Control—
for,while,continue, break
for n = 1:9
for m=1:n
r(n,m)=m*n;
end
if n>5, continue; end
end
r
2.4 Flow control
2.loop Control—
for,while,continue, break
fibnacci
f(1)=1;
f(2)=1;
n=1;
while f(n)+f(n+1)<30
f(n+2)=f(n)+f(n+1);
n=n+1;
end
f
2.4 Flow control
3.error Control—
try,throw catch
try
statement
...
statement
catch exceptObj
statement
...
statement
end
2.4 Flow control
3.error Control—
try,throw,catch
try
statement
…
statement
catch err
statement
...
statement
end
clear
a=magic(4);
b=eye(3);
try
c = a * b;
[na,ma]=size(a);
[nb,mb]=size(b);
if (ma~=nb)
error('afdas');
err = MException('whj:NotMatch','A=(%d,%d),B=(%d,%d)',na,ma,nb,mb);
throw(err);
end
catch err
c=a(1:3,1:3)*b
if (strcmp(err.identifier,'whj:NotMatch'))
err
else
rethrow(err);
end
end
exception = MException(msgIdent, msgString, v1, v2, ...)
exception = MException('AcctError:Incomplete', ...
'Field ''%s.%s'' is not defined.', ...
'Accounts', 'ClientName');
exception.message
ans =
Field 'Accounts.ClientName' is not defined.
2.5 Graphics
1. 2D Graphics
plot, plotyy, subplot,
loglog, semilogx,semilogy
hist,histc,staris
area, fill, pie, bar,barh,
stem, errorbar, polar,rose,
fplot,ezplot
scatter, Image,imagesc,
pcolor,imshow
2.5 Graphics
2. Figure tool
grid on, grid off
title, xlabel, ylabel, zlabel, text
axis ij, axis equal
close
2.5 Graphics
3. 3D Graphics
plot3,pie3
mesh,meshc,meshz
surf,waterfall,surfc
contour,quiver,fill3
tem3,slice,scatter3
2.5 Graphics
3. 3D Graphics
Dis3D_topo_demo
2.5 Graphics
4. Others plot
Plot catalog
select a variable from the
workspace and see the graphics
menu …
Chap3. M-file
programming
3.1 Scripts m-file
3.2 function m-file
3.3 Function calls and
parameter passing
3.4 Debug m-file
3.1 Scripts m-file
1. Just only composed by
a bunch of instruction set
(including the control
flow of instructions
including )
42
3.1 Scripts m-file
2. Variable storaged in
the base workspace
shared with the
command window.
3.1 Scripts m-file
3. Example
%circle.m
clf;
r=2;
t=0:pi/100:2*pi;
x=r*exp(i*t);
plot(x,'r*');
axis('square');
3.2 function m-file
1. Just only add a
function declare line in
the scripts m-file.
function y = mean(x)
% claculate the mean value
% for vecter, mean(x) return the mean value
% for matrices, MEAN(x) is a vecter, each element is the mean value of the Column vecter of matrces.
% whi, 1/25/2012
[m,n]=size(x);
if m==1
m=n;
end
y=sum(x)/m;
3.2 function m-file
2. Variable storaged in
the function workspace
separated with the
command window.
46
3.2 function m-file
3. Primary and Subfunctions
funciton a = prifun(x)
…..
r=3;
a = 2 + subfun(r);
function b = subfun(r)
…
47
3.2 function m-file
4. style
Declare function line
%Comment line
%Help online zone (lookfor、help)
%Edit record and copyright infomation
Function body
48
3.3 Function calls and
parameter passing
1. Local and global variable
K = 1;
ki = 105;
f = anim(K,ki);
image(f.cdata);
49
3.3 Function calls and
parameter passing
2. Functions calls
[out1,out2,~,out3] = fun(in1,in2,…);
function [y1,y2,y3] = fun1(x1,x2,x3)
% demo functions calls
% x1,x2,x3: input argument parameters
% y1,y2,y3: output argument parameters
%{
[y1,~,y3] = fun1(1,2,4);
%}
% whj,1/25/2012
y1 = x1+x2;
y2 = x2+x3;
y3 = x3+x1;
50
3.3 Function calls and
parameter passing
3. Parameter passing with
adjustable parameters
K = 1;
ki = 105;
f = anim(K,ki);
image(f.cdata);
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3.3 Function calls and
parameter passing
3. Parameter passing with
adjustable parameters
argin
argout
52
3.3 Function calls and
parameter passing
4. Pass across the space variable
x= evalin(‘base’, ‘K’)
53
3.4 Debug m-file
1. Two type errors
Syntax
variable name error …
Run-time
Algorithm error
54
3.4 Debug m-file
2. Using debug tools
55
Debug tool
 Debug menu
Continue：恢复程序运行至结束或另一个断点 。
Single Step：单步执行函数。
Step In：深入下层局部工作区 。
Quit Debugging：退出调试状态。
Set/Clear Breakpoint：设置/清除光标处的断点 。
Clear All Breakpoints：清除程序中的所有断点 。
Stop if Error：运行至出错或结束。
Stop if Warning：运行至警告消息或结束。
Stop if NaN of Inf：运行至运算结果出现 NaN 或 Inf。
Chap4. Advanced
programming
4.1 File Operate
4.2 Graphice User Interface(GUI)
4.3 Application Programming
Interface(API)
4.4 complier
4.1 File Operate
1.
2.
3.
4.
5.
fopen,fclose
fread,fwirte
xlsread,xlswrite
getline
Fprintf
59
（1）open &close
fid=fopen(‘datafile’，‘r’)
‘r’ —— read
‘w’ —— write
‘a’ —— add
‘rt’ —— read &write
浙江大学地球科学系
王华军
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（1）open &close
fclose(fid)
fclose(all)
61
close fid
close all
（1） open &close
For spacial *.mat
save
load
浙江大学地球科学系
王华军
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（2）read &write
fread
fwrite
63
（2）Example(Binary)
%write
a=1:50;
fid=fopen('user.dat', 'w');
fwrite(fid,a);
fclose(fid);
浙江大学地球科学系
王华军
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(2) Example(Binary)
%read
fid=fopen('user.dat','r');
a=fread(fid,50);
fclose(fid);
(3) Examples
1.(newful) mrrDpro.m
2.(newfel) 2D visulization
3. actic em31 figure
4. 3dVisualize
4.2 Graphice User
Interface(GUI)
67
Graphice User Interface(GUI)
 MATLAB能够以比较简单的方式实现一系列的图形界面功能。通过对控
件、菜单属性的设置和 Callback 的编写，就能够满足大多数用户的需
求。
 控件的 Callback 属性： Callback 属性的取值是字符串，可以是某个
M文件名或一小段MATLAB语句。当用户激活控件对象（例如 ：在控件对象
图标上单击鼠标左键 ）时，应用程序就运行 Callback 属性定义的子程
序。
 菜单的 Callback 属性： Callback 属性的取值是字符串，可以是某
个M文件名或一小段MATLAB语句。当用户激活菜单对象时，若没有子菜单
就运行 Callback 属性定义的子程序。若有，先运行 Callback 属性定
义的子程序，再显示子菜单。
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4.3 Application
Programming Interface
Interface with
C,fortran,excel
69
4.3 Application
Programming Interface
Example for C
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4.4 complier
1.mcc
mcc[-options] fun [fun2 ...]
[mexfile1 ...] mlibfile1 ...]
2.Tools
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4.4 complier
2.Tools
•
•
Deployment project
Code Generation Project
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4.4 complier
2.Tools
•
•
Deployment project
Code Generation Project
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Practice and practice
一旦你学会了基本语法，设计程序的能力
取决于你的知识和掌握函数的多少及熟练
程度.
Once you learn the basic syntax, the
ability of the program design
depends on your knowledge and how
many functions you have mastered and
proficiency.
Thanks!