# 程序代写代做代考 matlab Matlab: An Introduction

Matlab: An Introduction

Introduction to MATLAB

Mike (Y-Q.)
yqmiao@uwaterloo.ca

Sept 2014

mailto:yqmiao@uwaterloo.ca

outline

• what’s  matlab?
• interface
• basics
• an example
• how to access
• help

what is it?

• MATrix LABoratory, by MathWorks
– high-level programming language
– so,  it’s  very  simple  to  code
– rich in libraries and graphical subroutines
– transportable across platforms
– a great tool for rapid prototyping
– not the best for real-time applications

interface

• command window
• workspace
• current directory
• command history
• array editor
• text editor

basics

• ‘Hello  World!’
– a = 3;
– b = 4;
– c = a + b

• end each statement with semicolon, if you do
not like to see the result in the command
window

basics
• arithmetic operators:

– subtraction: A-B
– multiplication: A*B
– right division: A/B = A*inv(B)
– left division: AB = inv(A)*B
– power: A^b
– transpose:  A’
– colon operator:

• to create vectors: a:b
• array subscripting: A(:,b)

basics

• dot operators (a.k.a element-wise operators)
A.*B, A./B, A.B, and A.^B

• relational operators
ab, a>=b, a==b, and a~=b

• logical operations
a||b (or), a&&b (and), ~ a(not)

• element-wise logical operators
A|B, A&B, ~A

basics

• operator precedence
– Parentheses
– transpose and power
– unary plus, unary minus, and logical negation
– multiplication(s) and division(s)
– addition and subtract
– …

basics

• flow control
– conditional control

• if, else, and elseif
• switch and case

– loop control
• for
• while
• break
• continue

basics

• if
if expression1

statements1

elseif expression2
statements2

else
statements3

end

basics

• for
for index = values

program statements

end

• while
while expression

program statements

end

basics

• function definition
– function [output_variables] =
fcn_name(input_variables)

– the name of a function should be consistent with
the file name

an example

• Given the corresponding coefficients of two lines
(ax+by+c=0), calculate the intersection point and
plot the lines on a figure.

• Function:
[intersection,Runtime] = myPlot(line1,line2)

• Script to call this function:
clear all;clc
line1 = coeff(1,:);
line2 = coeff(2,:);
[intersection,RunTime] = myPlot(line1,line2)

how to access?

• have a license
• Nexus computers

– on campus
– remotely

• Octave

help

• where to look for answers?
– Matlab Help
– Mathworks website
– Online forums
– TAs

refs

• www.mathworks.com
• www.gnu.org/software/octave/
• saw.uwaterloo.ca/matlab/

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