Adding legend in a plot genereted by a loop
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Martin Nors Pedersen
on 5 Feb 2013
Commented: sanjay Negi
on 26 Oct 2021
Hello everyone
i have a lot of x,y data sets that i would like to plot. The data sets are stored in a cell structure so that
- DataFiles(1,1) is the first data set i imported
- DataFiles(1,2) is the second
- DataFiles(1,1).data(:,2) is all the y values of the first data set
and so on. the names of the data sets are furthermore stored in OutFiles so that
- OutFiles(1,1).name is the name of the first data set
- OutFiles(2,1).name is the name of the second data set
and so on. because i would like to plot all the x,y data set togehter i wrote a loop. the code is shown below
figure( 'Name', 'Reduced data' );
title('Reduced Raw data')
cc = jet(length(OutFiles)); % creates colormap
% log-lin plot
subplot(2,1,1)
h1 = subplot(2,1,1);
set(h1, 'xscale', 'lin')
set(h1, 'yscale', 'log')
xlabel('Q (Å^{-1})','fontsize',14)
ylabel('Detector counts in 1 sec.')
hold on
for k = 1:length(OutFiles)
plot(DataFiles{1,k}.data(:,1),DataFiles{1,k}.data(:,2), 'color', cc(k,:));
end
+ the other subplot which is just a log-log plot of the same
My problem is that i cannot figure out how i can include the legends in the plot. i have tried include "legend" in the loop so that the loop code becomes
for k = 1:length(OutFiles)
plot(DataFiles{1,k}.data(:,1),DataFiles{1,k}.data(:,2), 'color', cc(k,:));
legend(OutFiles(k,1)
end
but this does not work. Simply adding legend(OutFiles) also does not work but OutFiles also contains more information than ".name". i thought about making an array of the names "Legend(1,length(OutFiles))" but i do not know how to make an array of strings. i tried using
>> Legend=zeros(1,10); >> Legend(1,8) = 'test' Subscripted assignment dimension mismatch.
but as you can see i cannot add a string to an array
does anyone have a suggestion on how to add legends to plots made using a loop? any help will be greatly appreciated :)
1 Comment
mazari ahmed
on 12 Aug 2015
l want to make a legend for my figure but l have 3 for loops with three plots like mentioned below : legend 1 : essential legend 2 : less essential legend 3 : most important
for P=1:K
% body
plot(.....,'bo');
end
for Z=N:T
%body
plot(....,'ro'):
end
for i=1:L
%body
plot(....,'ko'):
end
how can l manage my legend ? thank you
Accepted Answer
Youssef Khmou
on 6 Feb 2013
hi, you plot all the data first, and then manipulate the Legend using per example cells as shown below :
for k = 1:length(OutFiles)
plot(DataFiles{1,k}.data(:,1),DataFiles{1,k}.data(:,2), 'color', cc(k,:));
end
Legend=cell(2,1)% two positions
Legend{1}=' Your data 1' ;
Legend{2}=' Your data 2';
legend(Legend);
In case there are many legends, like N plots, then you do :
Legend=cell(N,1)
for iter=1:N
Legend{iter}=strcat('Your_Data number', num2str(iter));
end
legend(Legend)
8 Comments
Shivam Chopra
on 1 Jun 2020
Hi, can you help me in my case??
Thanks in advance
p = (1);
B = [1E-9 1E-8 1E-7 1E-6 1E-5 1E-4 1E-3];
figure();
cc = jet(length(B)); %creates colormap
for k = 1:length(B)
abs_z = diffusion(B(k));
f = (0:10:10^5);
p(k) = plot(log10(f),log10(abs_z), 'color', cc(k,:));
hold on;
end
hold off;
function abs_z = diffusion(B)
t_n = 1E-6;
d_n = 1E+6;
q = 1.6E-19;
m_n = 9.11E-31;
w_c = (q * B)/(m_n);
f = (0:10:10^5);
w = f.*(2*pi);
d_real = 1 + ((t_n^2) * ((w.^2) + (w_c^2))) ;
d_img = w.*((t_n)*((t_n.^2) * (((w_c.^2) - w.^2)-1))) ;
d_divider = (1 + ((t_n.^2) * (((w_c.^2) - w.^2).^2)) + ((w.*2*(t_n)).^2)) ;
z = complex(d_real,d_img);
d_m = d_n./d_divider;
abs_z = abs(z).*d_m;
end
More Answers (1)
Samuel Hammarberg
on 30 May 2019
When I loop through folders etc. containing data I want to plot, I usually use the 'DisplayName' option.
Example of what my plotscripts typically includes.
% This script plots force vs displacement stored in the Data struct.
figure, hold on
h = legend('show','location','best');
set(h,'FontSize',12);
for i=1:length(Data) % Data is a struct containing my data.
x = Data(i).displacement;
y = Data(i).force;
name = Data(i).name; % Some text string which i usually take from the folder of each data set in Data.
plot(x,y,'-x','LineWidth',2,'MarkerSize',2,'DisplayName',name)
end
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