matlab -nojvm

editing files: xemacs

most important command:

help <function name>

a = [1 3 4 5];

>> b = [2 3 4; 5 6 7; 4 5 6]

b =

2 3 4

5 6 7

4 5 6

>> x = 1:5:20

x =

1 6 11 16

disp(a)

Useful stuff to know for later

pi

load <filename (.txt .mat)> - make a text file with some numbers

save <filename>

clear, clear all : empty out whatever variables you created

who, whos : list the current variables you created

cd pwd ls : same function as in unix

** for**

x=[];

for (i = 1:n)

x = [x,i^2]

end

** while
** while (input('again? ', 's') == 'y')

disp('one more time')

end

again? y

one more time

again? y

one more time

again? n

** if else**

if (1 > 2)

disp('error')

else

disp('whew')

end

Also try if...elseif...else

Useful functions

randn, rand

abs sqrt cos sin log exp

^ * + - /

== && ||

Scripts (.m files), editing, comments (%)

Plot(rand(100,1))

Hold on: next plot command writes ontop of last one, rather than clearing
it.

plot(50,0.5,'o')

Stuff to play with later:

Title xlabel ylabel

Surf/mesh: surf(rand(8,8))

Close: close the current figure window

Subplot(3,4)

Figure(3)

Cla clf : delete parts of the plot, or all of it

Ginput: get X and Y values from a plot; not snapped to the line

Load/save/open figures

% Line plot of a chirp

x=0:0.05:5;

y=sin(x.^2);

plot(x,y);

Eye(3)

Ones(2,5)

Zeros(5,2)

Size(a)

>> diag([1 2 3])

ans =

1 0 0

0 2 0

0 0 3

A'

A .* B

>> a(:,3)

ans =

3

3

>> a(1, 3:5)

ans =

3 4 5

>> a(1:2, 4:5)

ans =

4 5

4 5

Sum(A)

Prod()

>> max([1 2 9 3])

ans =

9

>> [amount, location] = max([1 2 9 3])

amount =

9

location =

3

max min mean

In class assignments:

1. load a list of numbers from a file

2. square them

3. plot them

4. save the figure

5. save the squared numbers

1. enter number N between 5 and 10

2. repeat until user enter valid number

3. print numbers from 1 to N

1. generate 100 random numbers: rand(100,1)

2. plot them as a function

3. compute 5-point running average (using for-loop): 96 nums

4. plot running average on top of rands (different color)

5. find minimum of run av (value and index)

6. plot circle at minimum