Structure Definition

Explicit Structure Declaration

struct...not strut

a = struct('b', 0, 'c', 'test')

b = a.b

c = a.c

no data

Ball = struct('mass',{},'position',{},'velocity',{},'radius',{});

with data

BALL(1) = struct('mass',10,...

'position',[0 0 100],...

'velocity',[0 0 0],...

'radius', 3);

example

stocks=struct('name',{'GOOG','AAPL'},'full',...

{'Google Inc.','Apple Inc'},...

'value',{522.35,278.64},'quant',200)

stocks(2).full

Implicit Structure Declaration

.

data.x = linspace(0,2*pi);

data.y = sin(data.x);

data

data.x

data.y

patient(1).name = 'John Doe';

patient(1).billing = 127.00;

patient(1).test = [79, 75, 73; 180, 178, 177.5; 220, 210, 205];

patient

patient(2).name = 'Ann Lane';

patient(2).billing = 28.50;

patient(2).test = [68, 70, 68; 118, 118, 119; 172, 170, 169];

patient

patient(3).name = 'New Name';

patient(3)

Extract Data from Structure

amount_due = patient(1).billing

Plot Structure Data

bar(patient(1).test)

title(['Test Results for ', patient(1).name])

Build from Outside-in

people(1).name = 'john';

people(1).job = 'manager';

people(1).id = 123456;

people(2).name = 'mary';

people(2).job = 'owner';

people(2).id = 567890;

people(3).name = 'justin';

people(3).job = 'singer';

people(3).id = 246801;

people(1).name

people(2).name

people(3).name

people(:).name

a = people(:).name

a = [people(:).name]

ball.mass = 10;

ball.position = [0, 0, 100];

ball.velocity = [0, 0, 0]

ball.position = ball.position + [0 10 0]

ball.radius = 3

ball(2:3,1)=ball

ball(1).mass = 1.0

ball(2).mass = 5.0

ball(3).mass = 10.0

ball.mass

m = [ball.mass]

totalMass = sum([ball.mass])

Build from Inside-out

NameData.First = 'John';

NameData.MI = 'J';

NameData.Last = 'Doe';

Assign to higher level element

StudentData.Name = NameData;

Create additional fields

StudentData.Status = 'Brilliant';

StudentData.HW = 10;

StudentData.Exam = linspace(100,100,3);

View Structure

StudentData

StudentData.Name

StudentData.Exam

Edit Structure Elements

StudentData.Exam(3) = 0;

StudentData.Exam

StudentData.Name.First = 'Jane';

StudentData.Name

Arrays of Structures

num_students = 5;

for i=1:num_students

ClassData(i) = StudentData;

end

ClassData

ClassData(2)

Structures in Functions

message = pass_or_fail(ClassData(2));

message

pass_or_fail.m

function message = pass_or_fail(StudentData)

Exam_avg = mean(StudentData.Exam);

if Exam_avg >= 70

message = 'You pass!';

else

message = 'You fail!';

end

return;

Nested Structures

Syntax

structName(index).nestedStructName(index).fieldName(indices)

s(1).n(2).a = 2*ones(3);

s(1).n(2).b = 2*eye(4);

s(1).n(2).c = 2*magic(5);

s(2).n(1).a = '1a';

s(2).n(2).a = '2a';

s(2).n(1).b = '1b';

s(2).n(2).b = '2b';

s(2).n(1).c = '1c';

s(2).n(2).c = '2c';

Access Data in a Structure Array

S = load('clown.mat')

image(S.X)

colormap(S.map)

upperLeft = S.X(1:50,1:80);

image(upperLeft);

Structure Tools

isfield

if isfield(s,'field3')

s.field3

else

'no field3 found'

end

fieldnames()

fieldnames(s)

Algorism and Bushism of the Day


"I frankly felt like the reception we received on the way in from the airport was very warm and hospitable. And I want to thank the Canadian people who came out to wave -- with all five fingers -- for their hospitality."	"It's a wise father who knows his child" the real proverb goes, 'It's a wise child who knows its father'

Lesson of the Day

Formal education will make you a living; self-education will make you a fortune.

If you don't design your own life plan, chances are you'll fall into someone else's plan. And guess what they have planned for you? Not much.

How long are you going to wait before you demand the best for yourself?

"Is the noise in my head bothering you?"

The monologue that runs in our brain is loud. It's heavy-metal loud compared to the quiet signals we get from the rest of the world.

All day, every day, that noise keeps going. It's the only voice that has seen everything we've seen, believes everything we believe. It's the noise that not only criticizes every action of every other person who disagrees with us, but it criticizes their motives as well. And, if we question it, it criticizes us as well.

Is it any wonder that projection is more powerful than empathy?

When we meet people, we either celebrate when they agree with us or plot to change or ignore them when they don't. There's not a lot of room for, "they might have a different experience of this moment than I do."

That noise in our head is selfish, afraid and angry. That noise is self-satisfied, self-important and certain. That noise pushes intimacy away and will do anything it can to degrade those that might challenge us.

But, against all odds, empathy is possible.

It's possible to amplify those too-quiet signals that others send us and to practice imagining, even for a moment, what it might be like to have their noise instead of our noise.

If we put in the effort and devote the time to practice this skill, we can get better at it. We merely have to begin.

Structures