How do I skip items in a legend?
4,782 views (last 30 days)
Show older comments
henry wang
on 25 Jan 2011
Answered: Image Analyst
on 25 Sep 2024
How do I skip items in legend? Say I have 6 plots with 3 actual values and 3 interpolated curves. I only want to label the actual value curves so
legend('first','','second','','third')
doesn't really work because the interpolated curve still shows.
14 Comments
Greg Vieira
on 4 Sep 2021
How can you do this for multiple plots? For example, I have 1001 data sets plotted and only want the legend to show 1 of the first 1000 plots and the last plot. It is not reasonable for me to place 999 ' ' placeholders.
Kaveh Vejdani
on 10 Jun 2023
First plot data1, then data1001, the set L.AutoUpdate = 'off'; % L=Legend
Accepted Answer
Kenneth Eaton
on 29 Aug 2023
Edited: MathWorks Support Team
on 10 Jan 2022
Starting in R2021a, you can leave an item out of a legend by setting the corresponding label to an empty character vector. For example, plot three lines. Then call the legend function and specify the second legend label as an empty character vector. The corresponding line is omitted from the legend.
plot(rand(3)); legend('Line 1','','Line 3')
Note that this strategy works when you specify just the labels, and not when you specify a set of objects to include in the legend.
For previous releases, you can specify the objects that you want to include as the first input argument to the “legend” function.
For example, plot three lines and return the “Line” objects as array “p”. Include only the first and third lines in the legend by specifying “p(1)” and “p(3)” as the first input argument to “legend”.
p = plot(rand(3));
legend([p(1) p(3)],'plot 1','plot 3')
Alternatively, you can set the “IconDisplayStyle” to “off” for the object that you do not want to include in the legend. For example, exclude the second “Line” object, “p(2)”.
p = plot(rand(3));
set(get(get(p(2),'Annotation'),'LegendInformation'),'IconDisplayStyle','off');
legend('plot 1','plot 3')
10 Comments
DGM
on 18 Oct 2022
Edited: DGM
on 18 Oct 2022
I was responding to @Dan Houck who was asking specifically for a means to avoid the implicit item removal that happens in R2021a. Leaving the unlabeled marker was the goal.
As to whether what Dan asked for is visually objectionable, you're free to tell him.
More Answers (13)
Matt Lobo
on 1 Nov 2021
Edited: Matt Lobo
on 30 Nov 2021
A really good method is to do what's mentioned at https://stackoverflow.com/questions/13685967/how-to-show-legend-for-only-a-specific-subset-of-curves-in-the-plotting.
Essentially set the 'HandleVisibility' attribute to 'off' when plotting something, as such:
plot(x,y,'HandleVisibility','off')
This has some implications concerning interacting with that handle in other ways, but if you don't plan on using the handle, this is a great dynamic way to not include certain plots in your legend. It works especially well when you're plotting iteratively, and don't want to store handles and then hard-code the legend to fit your exact plot.
5 Comments
Walter Roberson
on 25 Jan 2011
Edited: Rik
on 5 Apr 2022
You can set the IconDisplayStyle to off for the items you do not wish a legend for. See this documentation.
The link above was valid for the documentation from R2012a. The equivalent page in R2022a suggests a different strategy (i.e. only providing the handles to legend for the objects you wish to include). In the current release IconDisplayStyle is documentated under the properties of the graphics primitives (e.g. line objects or patch objects).
Documentation pages from specific releases will remain online for 5 years.
6 Comments
Junette Hsin
on 21 Mar 2019
Edited: Junette Hsin
on 21 Mar 2019
I ran into this problem and I have not seen this method suggested yet, but I solved it by changing the order of my plotted lines which affects what the legend displays (I am using MATLAB R2017b).
Let's say you plot 2 lines first, and then create a legend. Then you plot a 3rd line. That 3rd line will be added to your legend as 'data 1'.
Instead plot 3 lines, and then in your legend, label just the first 2 lines. The 3rd line will be omitted from the legend.
Hope this helps.
5 Comments
Brent F
on 22 Jun 2021
Edited: Brent F
on 10 Aug 2021
@Jim Tonti Yes! Upvote his solution: legend({'A','B'},'AutoUpdate','off')
Yasin Zamani
on 25 Sep 2019
Edited: Yasin Zamani
on 25 Sep 2019
For example, suppose you want to skip the name of the first plot in the legend:
x = linspace(0, 2 * pi);
% sin(x)
h = plot(x, sin(x));
% the following line skip the name of the previous plot from the legend
h.Annotation.LegendInformation.IconDisplayStyle = 'off';
% cos(x)
plot(x, cos(x));
% legend
legend('cos');
4 Comments
Boris Blagojevic
on 23 Jun 2021
An alternative approach: Prevent the legend from updating
First, plot the lines that you want to have labeled. Then, specify the legend and set
legend(....,'AutoUpdate','off')
then, plot the remaining lines
4 Comments
the cyclist
on 25 Jan 2011
Each curve has a handle, which can be obtained from the properties. Use the form of legend that takes two arguments (handle and legend), and only use the handles of those curves that you want to show.
0 Comments
Dilshad Raihan
on 26 Oct 2015
Edited: Dilshad Raihan
on 26 Oct 2015
You can do this by first plotting the curves in an order so that the lines you don't want to be displayed in the legend comes in the end. That is, suppose you have N lines to be plotted but you dont want to display m of these in the legend. Then first plot the required N-m lines and then the remaining m. After that, turn the legend on, click on the legend and the "legend property editor" will be displayed. Go to the "more properties" option. You can see an entry titled "String" specified as a "1xN cell array". Click on the cell array icon and set the size as "1xN-m". Now, only the first N-m curves will be displayed in Legend.
Diaa
on 17 Nov 2020
Edited: Diaa
on 17 Nov 2020
You can simply delete the last undesired entry by the following:
% assume you plotted some curves before this line and all of them are desired to be shown in the legend
hleg = legend('show');
plot(x,y) % you don't need this plot in the legend
hleg.String(end) = []; % delete the last legend entry of the very last plot
% continue plotting while copy and paste the previous line immediately after any plot you don't need in the legend
1 Comment
Amir Semnani
on 9 Jun 2021
Thanks. That worked for me (MATLAB 2017b) and it's very simple. Let's assume we have 8 datasets and we want to plot all of them, but only want to see the legend for dataset with even number.
x=ones(100,1)*(1:8); plot(x);ylim([0 9]); hleg = legend ('show'); hleg.String(1:2:end)=[];
Akshay Ravindran
on 26 Nov 2015
Why is it that this error keeps coming up?
<<
>>
3 Comments
Ajith Tom George
on 17 Nov 2016
If z,x,c etc are the handles, then remove the commas:
i.e. [z w c ...] and you are good to go!
Walter Roberson
on 17 Nov 2016
No, in each case where z w c etc are expressions that have no spaces in them, [z w c ...] is the same as [z, w, c, ...]
Spaces in expressions sometimes trigger parsing as if there were multiple expressions. For example:
[1 -2*x]
is considered two expressions, 1 and -2*x
Luke Marsden
on 2 Feb 2017
I am trying to do a similar thing using this line of code:
leg = legend([p4 RETU_Average activity1 Vulcanian1], 'Tilt', 'RETU Mean Amplitude', 'Activity', '"Vulcanian" Explosions', 'Location', 'northeast');
I am getting this error:
Error using matlab.graphics.chart.primitive.Line/horzcat
Cannot convert double value 23 to a handle
Error in p1_zoom_plot (line 93)
leg = legend([p4 RETU_Average, activity1 Vulcanian1], 'Tilt', 'RETU Mean Amplitude', 'Activity', '"Vulcanian" Explosions', 'Location', 'northeast');
4 Comments
Brent F
on 10 Aug 2021
Have you gotten this method of generating a legend using plot handles to work within a subplot?
Juan Carlos de Luna
on 6 Apr 2020
Select line in Plot Browser and type
set(get(get(gco,'Annotation'),'LegendInformation'),'IconDisplayStyle','off')
2 Comments
K Anderson
on 30 Aug 2024
If you plot multiple lines with the same plot command like this
h(1,:) = plot(rand(4,11),'r')
hold on
h(2,:) = plot(rand(4,11),'b')
and use
legend
on this, you get a 2x11 long legend
but you only want to highlight the first red and first blue line use this;
legend([h(1,1) h(2,1)],'red','blue')
This is mentioned in the documentation as;
legend(subset,___) only includes items in the legend for the data series listed in subset. Specify subset as a vector of graphics objects. You can specify subset before specifying the labels or with no other input arguments.
0 Comments
Image Analyst
on 25 Sep 2024
Every time you plot, get the handle to the points or curves. Then pass only those that you want into legend. Here is a full demo:
lineSize = 2;
markerSize = 30;
% Define 3 data sets
x1 = [-1.9, 0.004, 1.94];
x2 = [-1.94, -0.23, 1.95];
x3 = [-1.92, .2, 1.93];
y1 = [13.885, 10.168, 14.235];
y2 = [9.3805, 5.2697, 9.3367];
y3 = [4.5262, 0.80904, 4.0889];
% Interpolate the 3 curves.
xFit = linspace(-2, 2, 500);
coefficients1 = polyfit(x1, y1, 2);
yFit1 = polyval(coefficients1, xFit);
coefficients2 = polyfit(x2, y2, 2);
yFit2 = polyval(coefficients2, xFit);
coefficients3 = polyfit(x3, y3, 2);
yFit3 = polyval(coefficients3, xFit);
% Plot the 3 data sets and their interpolated curves
handle1 = plot(x1, y1, 'r.', 'MarkerSize', markerSize);
hold on;
handle2 = plot(xFit, yFit1, 'r-', 'LineWidth', lineSize);
handle3 = plot(x2, y2, 'b.', 'MarkerSize', markerSize);
handle4 = plot(xFit, yFit2, 'b-', 'LineWidth', lineSize);
handle5 = plot(x3, y3, 'g.', 'MarkerSize', markerSize);
handle6 = plot(xFit, yFit3, 'g-', 'LineWidth', lineSize);
grid on;
% Have the legend only for the data, not the interpolated fit
% by passing in only the plot handles of the data.
legend([handle1, handle3, handle5], 'Data1', 'Data2', 'Data3', 'Location', 'north');
0 Comments
See Also
Categories
Find more on Legend in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!