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:
– addition: A+B
– subtraction: A-B
– multiplication: A*B
– right division: A/B = A*inv(B)
– left division: A\B = 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
a
• 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
load coeffs
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/