Designing Effective Graphics Using MATLAB

Designing Effective Graphics Using MATLAB

The Cain Project in Engineering and Professional Communication

Linda Driskill, [email protected]

Gang Cheng, [email protected]

2

The Purpose of Using Graphs

• In problem solving As part of design

As analysis of operating data

• For persuasion and interpretation Dramatize relationships

Promote identification

Make complex information accessible

3

Checklist for Good Graphics

• Purpose clear?

• Critical components defined?

• Pattern and arrangement lead eye without distraction?

• Graphic hierarchy consistent?

• Fonts legible?

• Presenter’s expertise shown?

4

Types of Graph in Matlab

• Line graph 2D 3D

• Bar graph

• Pie graph

• Ribbon graph

5

Considerations

• Purpose Problem solving? Persuasion and interpretation?

• Audience What are their background? What are they interested to know?

• Context Presentation? Report/Paper?

6

Context

• Presentation Big fonts Can use any color Can use animation

• Report Smaller fonts Often just black and white Animation impossible

7

An Example

• You have: Vector 1: x[0:0.2:10]; Vector 2: sin(x); Vector 3: cos(x);

• You are asked to: Plot sin(x) vs. x and cos(x) vs. x in the same

figure; Customize the figure so that it becomes

suitable for being used in a presentation. Customize the figure so that it becomes

suitable for being used in a report/paper.

8

A Simple Matlab Program

%startclear all; %clear the memoryX=[0:0.2:10]; %define the x

vectorsinx=sin(x); %calculate sin(x)cosx=cos(x); %calculate sin(x)plot(x,sinx,x,cosx); %plot the linesxlabel('x'); %add x labelylabel('y'); %add y labeltitle([‘sin and cos Functions']); %add title%end

9

Default Figure Given by Matlab

0 1 2 3 4 5 6 7 8 9 10-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

x

y

sin and cos Functions

10

We Want …

• Titles and labels bigger.

• Lines thicker.

• Colors more contrasting.

• Insert Legend.

• Data points shown.

• Try adding gridlines.

11

Anatomy of a Matlab Figure

0 1 2 3 4 5 6 7 8 9 10-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

x

y

sin and cos Functionstitle

Y label

X label

Tick and tick label

lines

Axes

12

Open the Property Editor

Figure Properties

13

Edit Figure Properties

Figure

Immediate apply

14

Edit Axes Properties

axes

15

Edit Line Properties

line

16

A Better-Looking Figure

0 2 4 6 8 10-1

-0.5

0

0.5

1

x

y

sin and cos Functions

17

Insert Legend

legend

18

Legend Inserted

Select object

19

Make Room for Legend

20

Edit Legend Properties

legend

21

Insert Y Grid Line

axes

Grid

Show

22

Final

0 2 4 6 8 10-1.5

-1

-0.5

0

0.5

1

1.5

x

y

sin and cos Functions

sin(x)cos(x)

23

Figure for Report/Paper

0 2 4 6 8 10-1.5

-1

-0.5

0

0.5

1

1.5

x

y

sin and cos Functions

sin(x)cos(x)

24

Frequently Used Functions

• “plot”• “xlabel”, “ylabel”• “title”• “xlim”, “ylim”• “axis”• “legend”• “errorbar”

• Type “help function name” in Matlab command window for detailed information on the usage of the function.

25

Other 2D Plotting Functions

• “loglog”: graph with logarithmic scales for both axes.

• “semilogx”: graph with a logarithmic scale for x-axis and a linear scale for y-axis.

• “semilogy”: graph with a logarithmic scale for y-axis and a linear scale for x-axis.

• “plotyy”: graph with y-tick labels on the left and right side.

26

A Whole Lot More …

• 2D contour “contour” “contourslice”

• 3D plots “plot3” “mesh” “surf”

• Movie “getframe” “movie”

27

Sample Movie

surfaces theallon 0.1 : B.C.

tissuet the throughou0 :I.C.

=

=

C

C

A Bioartificial Tissue Seeded

with CellsZ = 40

Z = 1

A movie created with mesh, getframe and

movie