How do I combine multiple plots in one graph?

Asked by Tom on 10 Dec 2011

Latest activity Commented on by Cleat Zeiler on 15 Oct 2019

5,006 views (last 30 days)

Hi, is there somewhere I can see some examples of scripts that result in multiple plots on one graph?

I know the 'hold' function is part of how to do it, but I'm very new to Matlab and I really need to see some full examples.

If someone could point me towards some that'd be great.

2 Comments

tayyaba khurshid on 4 Mar 2017

snr=0:1:15;
for ii=1:length(snr)
    x=randint(1,100000); % Generating bits
    y=pskmod(x,2); % Generating BPSK modulated data
    ynoisy=awgn(y,snr(ii)); % Adding AWGN noise to data
    z=pskdemod(ynoisy,2); % Demodulating
    error(ii)=length(find(x-z~=0));
end
semilogy(snr,error)
hold
snr=0:1:15;
for ii=1:length(snr)
    x=randint(1,100000); % Generating bits
    y=pskmod(x,4); % Generating QPSK modulated data
    ynoisy=awgn(y,snr(ii)); % Adding AWGN noise to data
    z=pskdemod(ynoisy,4); % Demodulating
    error(ii)=length(find(x-z~=0));
end
semilogy(snr,error)
grid

Chiemela Victor Amaechi on 26 Jul 2018

You can use this code, but to have multiple plots, you need the subplot which is used as follows:

% Code used in my paper on design of composite riser
% Create a vertical bar chart using the bar function
figure
subplot(2,3,1) % add fourth plot in 2 x 3 grid
bar(1:18, [FibreControl' FibreAxial'], 1)
% Add title and axis labels
title('(a)')
xlabel('Composite Riser Layers')
ylabel('Stress in Fibre Direction (MPa)')
% Add a legend
legend('[1.58:1.62:1.86]', '[1.84:1.62:1.86]')
% Set the axis limits
set(gca, 'XTick', 1:18)
set(gca, 'XLim', [0,19])
set(gca, 'Fontsize', 8)
subplot(2,3,2) % add first plot in 2 x 3 grid
bar(1:18, [FibreControl' FibreAngled'], 1)
% Add title and axis labels
title('(b)')
xlabel('Composite Riser Layers')
ylabel('Stress in Fibre Direction (MPa)')
% Add a legend
legend('[1.58:1.62:1.86]', '[1.58:1.88:1.86]')
% Set the axis limits
set(gca, 'XTick', 1:18)
set(gca, 'XLim', [0,19])
set(gca, 'fontname','arial','fontsize',8,'linewidth',1)
subplot(2,3,3) % add second plot in 2 x 3 grid
bar(1:18, [FibreControl' FibreHoop'], 1)
% Add title and axis labels
title('(c)')
xlabel('Composite Riser Layers')
ylabel('Stress in Fibre Direction (MPa)')
% Add a legend
legend('[1.58:1.62:1.86]', '[1.58:1.62:1.60]')
% Set the axis limits
set(gca, 'XTick', 1:18)
set(gca, 'XLim', [0,19])
set(gca, 'Fontsize', 8)

6 Answers

Link

Answer by Chandra Kurniawan on 10 Dec 2011

Edited by MathWorks Support Team on 9 Nov 2018

Accepted Answer

To combine multiple plots in one graph, use the “hold on” command, such as:

 plot(1:10)
 hold on 
 plot(11:20)
 hold off

For more information, see:

https://www.mathworks.com/help/matlab/creating_plots/combine-multiple-plots.html

3 Comments

Walter Roberson on 10 Dec 2011

The alternative to "hold on" that would be applicable to this example is

plot(t,x,'r',t,y,'b')

Ina Panci on 10 May 2019

Hello, what other letters can we use if we have more than two functions to plot?

Cleat Zeiler on 15 Oct 2019 at 22:02

This is the list from the help call:

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

w white v triangle (down)

^ triangle (up)

< triangle (left)

> triangle (right)

p pentagram

h hexagram

Link

Answer by N Narayan rao on 25 Sep 2016

Edited by Walter Roberson on 15 Jul 2017

x = -3:0.1:3;
y1 = sin(x);
y2 = cos(x);
y3= tan(x);
y4=1./cos(x);
figure
subplot(2,2,1)      
plot(x,y1)          
title('Subplot 1')
subplot(2,2,2)       
plot(x,y2)        
title('Subplot 2')
subplot(2,2,3)      
plot(x,y3)          
title('Subplot 3')
subplot(2,2,4)       
plot(x,y4)
title('Subplot 4')

0 Comments

Link

Answer by Tom on 10 Dec 2011

Thanks, that's perfect.

0 Comments

Link

Answer by Raghuram on 27 Mar 2014

Could you please tell me the same with scatter plot command? That is, to plot multiple scatter plots in one figure?

3 Comments

Prasad Kalane on 11 Dec 2015

x=rand(2,10);
scatter(x(1,:),x(2,:),'r');
hold on
x=rand(2,10);
scatter(x(1,:),x(2,:),'g');
hold on
x=rand(2,10);
scatter(x(1,:),x(2,:),'b');
hold on
x=rand(2,10);
scatter(x(1,:),x(2,:),'c');

You can plot multiple plot just use "hold on" command

MOHAMMAD YASIR ALI on 13 Jul 2017

can I get best fit line from this method?

Walter Roberson on 15 Jul 2017

"can I get best fit line from this method?"

Best fit lines tend to imply an ordering to the data, but scatter plots tend to imply the data might not be ordered in a way that is compatible with fitting.

But yes, if you have polynomial coefficients for your fit, such as coefficients generated using polyfit(), then you can use polyval() to interpolate values, and you can "hold on" and plot() the values.

Link

Answer by Cortney Marschner on 8 Oct 2016

Edited by Walter Roberson on 15 Jul 2017

How do I plot multiple graphs on the same graph using this code?:

hold off
[x, y] = meshgrid(0:0.2:10, 0:0.2:6);
X = x(1,1:51);
dx = ones(size(x));
dy = x;
quiver(x, y, dx, dy)
axis tight
hold on
plot(X, 1+X.^2/2)

1 Comment

Walter Roberson on 15 Jul 2017

That code already plots multiple lines on the same plot. However, the y range of the second one is much larger than the y range of the first, so the second one takes up most of the space.