10. Lines, Shapes, and Images

10.1         Generating lines

10.2         Forming and filling shapes

10.3         Loading images

10.4         Clicking in figure windows to add graphics, add text, or record responses

10.5         Saving and reloading figures

10.6         Practicing lines, shapes, and images

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10.1 Generating lines

Code 10.1.1

clear all

close all

figure(1)

x = [0 1];

y = [0 1];

our_first_line = plot(x, y);

box on

Output 10.1.1

Code 10.1.2

get(our_first_line)

Output 10.1.2

   Color = [0 0 1]

   EraseMode = normal

   LineStyle = -

   LineWidth = [0.5]

   Marker = none

   MarkerSize = [6]

   MarkerEdgeColor = auto

   MarkerFaceColor = none

   XData = [0 1]

   YData = [0 1]

   ZData = []

   BeingDeleted = off

   ButtonDownFcn =

   Children = []

   Clipping = on

   CreateFcn =

   DeleteFcn =

   BusyAction = queue

   HandleVisibility = on

   HitTest = on

   Interruptible = on

   Parent = [151.008]

   Selected = off

   SelectionHighlight = on

   Tag =

   Type = line

   UIContextMenu = []

   UserData = []

   Visible = on

Code 10.1.3

figure(2)

delta_y = .5;

our_second_line = plot([min(x)  max(x)], …

[min(y)+ delta_y max(y) + delta_y],'color',[1 0 0]);

box on

Output 10.1.3

Code 10.1.4

figure(3)

delta_y = 1;

our_third_line = plot([min(x)  max(x)], [min(y)+ 2*delta_y max(y) + 2*delta_y]);

set(our_third_line,'color',[.9 .5 .1], ...

    'linestyle','--', ...

    'linewidth',8);

box on

Output 10.1.4

Code 10.1.5

set(our_third_line)

Code 10.1.6

set(gca,'XGrid')

set(gcf,'PaperOrientation')

Output 10.1.6

[ on | {off} ]

[ {portrait} | landscape | rotated ]

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10.2 Forming and filling shapes

Code 10.2.1

function my_polygon_1(n,r,c)

x = linspace(0,2*pi,n+1)

x = r*cos(x

y = linspace(0,2*pi,n+1)

y = r*sin(y);

fill(x,y,c)

Code 10.2.2

figure(4)

my_polygon_1(4,1,[.5 .5 .5])

axis square

Output 10.2.2

Code 10.2.3

function my_polygon_2(n,r,c,turn)

x = linspace(0,2*pi,n+1)

x = x + (turn + 1/(2*n))*(2*pi);

x = r*cos(x);

y = linspace(0,2*pi,n+1)

y = y + (turn + 1/(2*n))*(2*pi);

y = r*sin(y);

fill(x,y,c)

Code 10.2.4

figure(5)

hold on

for turn = linspace(-.2,0,5)

    my_polygon_2(4,1,[.5 .5 .5],turn)

    axis off

end

Output 10.2.4

Code 10.2.5

figure(6)

crazy_x = rand(1,5);

crazy_y = rand(1,5);

f = fill(crazy_x,crazy_y,'g')

set(f,'LineWidth', 5.0);

Output 10.2.5

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10.3 Loading images

Code 10.3.1

figure(8)

a = imread('SR_Compat.jpg');

image(a)

axis off

Output 10.3.1

Code 10.3.2

figure(9)

b = imread('lab_photo.jpg');

image(b)

axis off

Output 10.3.2

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10.4 Clicking in figure windows to add graphics, add text, or record
responses

Code 10.4.1

clear x y

hold on

[x y] = ginput(2);

x = [x(1) x(2) x(2) x(1)];

y = [y(1) y(1) y(2) y(2)];

fill(x,y,'w');

Output 10.4.1

Code 10.4.2

clear x y

[x y] = ginput(1);

text(x,y,'Take the plunge!','rotation',90,'fontsize',24);

Output 10.4.2

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10.5 Saving and reloading figures

Code 10.5.1

saveas(gcf, 'SavedFig9','jpg')

Code 10.5.2

c = imread('SavedFig9.jpg');

image(c)