Various line types, plot symbols and colors may be obtained with PLOT(X,Y,S) where S is a character string made from one element from any or all the following 3 columns:

b blue . point - solid

g green o circle : dotted

r red x x-mark -. dashdot

c cyan + plus -- dashed

m magenta * star (none) no line

y yellow s square

k black d diamond

v triangle (down)

^ triangle (up)

< triangle (left)

> triangle (right)

p pentagram

h hexagram

For example, PLOT(X,Y,'c+:') plots a cyan dotted line with a plus at each data point; PLOT(X,Y,'bd') plots blue diamond at each data point but does not draw any line.

Code 9.4.3

figure(6)

plot(x,sin(x),'c+:',x,cos(x),'rd');

shg

Output 9.4.3:

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9.5 Getting and setting properties of plotted points

Code 9.5.1

figure(7)

plot(x,sin(x),'ro-','markersize',12);

xlim([min(x)-x_offset, max(x+x_offset)]);

ylim([min(y)-y_offset, max(y+y_offset)]);

box on

shg

Output 9.5.1

Code 9.5.2

figure(8)

h = plot(cos(x),sin(x), 'r.','markersize',12);

get(h)

Output 9.5.2

h =

Color: [1 0 0]

EraseMode: 'normal'

LineStyle: '-'

LineWidth: 0.5000

Marker: 'o'

MarkerSize: 12

MarkerEdgeColor: 'auto'

MarkerFaceColor: 'none'

XData: [1x100 double]

YData: [1x100 double]

ZData: [1x0 double]

BeingDeleted: 'off'

ButtonDownFcn: []

Children: [0x1 double]

Clipping: 'on'

CreateFcn: []

DeleteFcn: []

BusyAction: 'queue'

HandleVisibility: 'on'

HitTest: 'on'

Interruptible: 'on'

Selected: 'off'

SelectionHighlight: 'on'

Tag: ''

Type: 'line'

UIContextMenu: []

UserData: []

Visible: 'on'

Parent: 1.0710e+003

DisplayName: ''

XDataMode: 'manual'

XDataSource: ''

YDataSource: ''

ZDataSource: ''

Code 9.5.3

figure(9)

plot(x,y,'g-');

hold on

x_offset = 0;

y_offset = .2;

axis([min(x)-x_offset, max(x)+x_offset, …

min(y)-y_offset, max(y+y_offset)]);

plot(x,y,'o', ‘color’,’r’,'markersize',6,...

'markeredgecolor','k','markerfacecolor','r');

Output 9.5.3

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9.6 Adding xlabels, ylabels, and titles

Code 9.6.1

figure(10)

plot(x,y,'g-');

hold on

x_offset = 0;

y_offset = .2;

axis([min(x)-x_offset, max(x)+x_offset, …
min(y)-y_offset, max(y+y_offset)]);

plot(x,y,'o','color','r','markersize',6,...

'markeredgecolor','k','markerfacecolor','r');

xlabel('Time');

ylabel('Happiness');

title('Life has its ups and downs');

Output 9.6.1

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9.7 Adding legends

Code 9.7.1

figure(11)

max_learn = [10 11 12 13];

trial = [1:10];

c1 = max_learn(1) - exp(-trial);

c2 = max_learn(2) - exp(-trial);

c3 = max_learn(3) - exp(-trial);

c4 = max_learn(4) - exp(-trial);

hold on

plot(trial,c4,'g-^');

plot(trial,c3,'m--<');

plot(trial,c2,'b-.>');

plot(trial,c1,'k:v');

legend('Group 4','Group 3',…

'Group 2','Group 1', …

'Location','EastOutside');

Output 9.7.1

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9.8 Adding text

Code 9.8.1

figure(12)

a = 1; % starting value

b = .5; % rate parameter

xx = [0:20];

vert_offset = .05;

hor_offset = .50;

y_power = a * xx.^-b;

y_exp = a * exp(b*-xx);

hold on

box on

plot(y_power,'mo-');

plot(y_exp,'kd-');

hor_p = xx(5) + hor_offset;

vert_p = y_power(5) + vert_offset;

text(hor_p,vert_p,'Power function');

hor_e = xx(6) + hor_offset;

vert_e = y_exp(6) + vert_offset;

text(hor_e,vert_e,'Exponential function');

Output 9.8.1

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9.9 Fitting curves

Code 9.9.1

clear x y

a3 = 0;

a2 = 1;

a1 = 1;

a0 = 0;

x = [-20:20];

randn_coeff = 60;

y = a3*x.^3 + a2*x.^2 + a1*x.^1 + a0*x.^0;

r = rand(length(y))*randn_coeff;

r = r(1,:);

y = y + r;

fitted_coefficients = polyfit(x,y,1);

y_hat1 = fitted_coefficients(1)*x.^1 + ...

fitted_coefficients(2)*x.^0; %apply polyfit coefficients to x

figure (13)

hold on

plot(y,'bo'); % show original data

plot(y_hat1,'r-'); % show fitted points joined by a line

xlim([0 length(x)]);

box on % put a box around the graph

c = corrcoef(y, y_hat1);

message = ['Straight line fit: r^2 = ',num2str(c(1,2)^2,3)];

title(message);

Output 9.9.1

Code 9.9.2

clear fitted_coefficients;

fitted_coefficients = polyfit(x,y,2);

y_hat2 = fitted_coefficients(1)*x.^2 + ...

fitted_coefficients(2)*x.^1 + ...

fitted_coefficients(3)*x.^0;

figure (14)

hold on

plot(y,'bo'); % show original data

plot(y_hat2,'r-'); % show fitted points joined by a line

xlim([0 length(x)]);

box on % put a box around the graph

c = corrcoef(y, y_hat2);

message = ['Quadratic fit: r^2 = ',num2str(c(1,2)^2,3)];

title(message);

Output 9.9.2

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9.10 Creating subplots and turning grids, boxes, and axes on and off

Code 9.10.1

figure(15)

subplot(4,1,1)

plot(cos(x),'r.','markersize',12);

grid on

subplot(4,1,2)

plot(cos(x),'r.','markersize',12);

box on

subplot(4,1,3)

plot(cos(x),'r.','markersize',12);

axis off

subplot(4,1,4)

plot(cos(x),'r.','markersize',12);

axis square

Output 9.10.1

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9.11 Exploiting matrix assignments to merge subplots

Code 9.11.1

figure(16)

clear x y

x = [1:10];

y = x + 1;

subplot(4,2,1:2); % In the 4 rows and 2 columns of subplots,

% subplots 1 and 2

xlim([0 1]);

ylim([0 1]);

axis off

text(-.05,.05,' A Banner Year','fontsize',24);

subplot(4,2,3); % In the 4 rows and 2 columns of subplots,

% subplot 3

plot(x,y,'k')

text_in_box(.05,.80,'A')

subplot(4,2,4); % In the 4 rows and 2 columns of subplots,

% subplot 4

plot(x,y,'k')

text_in_box(.05,.80,'B')

subplot(4,2,[5 7]); % In the 4 rows and 2 columns of subplots,

% subplots 5 and 7

plot(x,y,'k')

text_in_box(.05,.90,'C')

subplot(4,2,6); % In the 4 rows and 2 columns of subplots,

% subplot 6

plot(x,y,'k')

text_in_box(.05,.80,'D')

subplot(4,2,8); % In the 4 rows and 2 columns of subplots,

% subplot 8

plot(x,y,'k')

text_in_box(.05,.80,'E')

Code 9.11.2

function text_in_box(x_place,y_place,s)

xs = xlim;

ys = ylim;

text(x_place*xs(2),y_place*ys(2),s);

Output 9.11.1

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9.12 Getting and setting properties of axes

Code 9.12.1

get(gca)

Output 9.12.1

ActivePositionProperty = outerposition

ALim = [0 1]

ALimMode = auto

AmbientLightColor = [1 1 1]

Box = on

CameraPosition = [12.5664 0.000251729 17.3205]

CameraPositionMode = auto

CameraTarget = [12.5664 0.000251729 0]

CameraTargetMode = auto

CameraUpVector = [0 1 0]

CameraUpVectorMode = auto

CameraViewAngle = [6.60861]

CameraViewAngleMode = auto

CLim = [0 1]

CLimMode = auto

Color = [1 1 1]

CurrentPoint = [ (2 by 3) double array]

ColorOrder = [ (7 by 3) double array]

DataAspectRatio = [12.5664 1.19975 1]

DataAspectRatioMode = auto

DrawMode = normal

FontAngle = normal

FontName = Helvetica

FontSize = [10]

FontUnits = points

FontWeight = normal

GridLineStyle = :

Layer = bottom

LineStyleOrder = -

LineWidth = [0.5]

MinorGridLineStyle = :

NextPlot = add

OuterPosition = [0 0 1 1]

PlotBoxAspectRatio = [1 1 1]

PlotBoxAspectRatioMode = auto

Projection = orthographic

Position = [0.13 0.11 0.775 0.815]

TickLength = [0.01 0.025]

TickDir = in

TickDirMode = auto

TightInset = [0.0928571 0.0904762 0.00357143 0.0547619]

Title = [1387]

Units = normalized

View = [0 90]

XColor = [0 0 0]

XDir = normal

XGrid = off

XLabel = [1385]

XAxisLocation = bottom

XLim = [0 25.1327]

XLimMode = manual

XMinorGrid = off

XMinorTick = off

XScale = linear

XTick = [ (1 by 12) double array]

XTickLabel = [ (12 by 2) char array]

XTickLabelMode = auto

XTickMode = manual

YColor = [0 0 0]

YDir = normal

YGrid = off

YLabel = [1386]

YAxisLocation = left

YLim = [-1.1995 1.2]

YLimMode = manual

YMinorGrid = off

YMinorTick = off

YScale = linear

YTick = [ (1 by 11) double array]

YTickLabel = [ (11 by 4) char array]

YTickLabelMode = auto

YTickMode = auto

ZColor = [0 0 0]

ZDir = normal

ZGrid = off

ZLabel = [1388]

ZLim = [-1 1]

ZLimMode = auto

ZMinorGrid = off

ZMinorTick = off

ZScale = linear

ZTick = [-1 0 1]

ZTickLabel =

ZTickLabelMode = auto

ZTickMode = auto

BeingDeleted = off

ButtonDownFcn =

Children = [ (2 by 1) double array]

Clipping = on

CreateFcn =

DeleteFcn =

BusyAction = queue

HandleVisibility = on

HitTest = on

Interruptible = on

Parent = [9]

Selected = off

SelectionHighlight = on

Tag =

Type = axes

UIContextMenu = []

UserData = []

Visible = on

Code 9.12.2

figure(17)

x = linspace(0,4*(2*pi),100);

y = sin(x);

plot(x,y);

plot(x,y,'g-');

hold on

x_offset = 0;

y_offset = .2;

axis([min(x)-x_offset, max(x)+x_offset, ...

min(y)-y_offset, max(y+y_offset)]);

plot(x,y,'o','color','r','markersize',6,...

'markeredgecolor','k','markerfacecolor','r');

xlabel('Time');

ylabel('Happiness');

title('Life has its ups and downs.');

set(gca,'xtick',[2:2:24]);

shg

Output 9.12.2

Code 9.12.3

figure(18)

plot(x,y,'g-');

hold on

x_offset = 0;

y_offset = .2;

axis([min(x)-x_offset, max(x)+x_offset, …

min(y)-y_offset, max(y+y_offset)]);

plot(x,y,'o','color','r','markersize',6,...

'markeredgecolor','k','markerfacecolor','r');

xlabel('Time');

ylabel('Happiness');

title('Life has its ups and downs.');

set(gca,'xtick',[]);

set(gca,'ytick',[]);

Output 9.12.3

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9.13 Plotting data points with error bars

Code 9.13.1

figure(19)

x= [1:10];

y = [4 11 25 65 141 191 313 301 487 673];

sd = [52 53 49 59 60 58 55 57 53 61];

box on

hold on

errorbar(x,y,sd,'k','markersize',18)

plot(x,y','w-',x,y,'k.','markersize',18)

shg

Output 9.13.1

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9.14 Generating polar plots

Code 9.14.1:

figure(20)

clear h i

h= [0:.1:2]*pi;

polar(h,h,'ko');

shg

Output 9.14.1:

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9.15 Generating histograms

Code 9.15.1:

figure(21)

randn('state',sum(100*clock))

h = randn(1,2000);

[N,X] = hist(h,6)

hist(h)

colormap([.5 .5 .5])

brighten(.75)

Output 9.15.1:

N =

17 47 171 384 460 468 272 131 41 9

X =

-2.7307 -2.0986 -1.4665 -0.8344 -0.2023 0.4298 1.0619 1.6940 2.3261 2.9582

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9.16 Generating bar graphs

Code 9.16.1:

figure(22)

a = [[3 4 5 6 7 6 5 4 3]];

barh(a)

colormap([.5 .5 .5]) % gray bars

% colormap([0 0 0] % black bars

% colormap([1 1 1]) % white bars

% colormap([1 0 0]) % red bars

% colormap([0 1 0]) % green bars

% colormap([0 0 1]) % blue bars

brighten(.15)

ylim([0 ,10])

xlim([0 8])

Output 9.16.1:

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9.17 Exporting and printing figures

Code 9.17.1:

figure(23)

plot([1:10],[1:10].^-3,'k-o')

print –f23 -r600 -djpeg my_first_figure_print

figure(24)

plot([1:10],[1:10].^-2,'k-s')

print -f24 –r800 -dtiff my_second_figure_print

ls *.jpg

ls *.tif

Output 9.17.1:

my_first_figure_print.jpg

my_second_figure_print.tif

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9.18 Generating other kinds of graphs and getting and setting figure properties

Code 9.18.1:

set(gcf, ‘position’, [464 581 672 504])