Remove the legends for some lines in a plot

Hello,

I want to plot some data points and fit a line to the data. I have done so and everything is ok; the only issue is there are some more items in the legend box corresponding to the fitted lines.

C=['b','r','g','m'];
format short
a=1:4;
for i=1:length(a)
    scatter(LT, Ra(i,:),C(i),'filled');
    hold on
end
grid on
grid minor
xticks([30, 40, 50, 60, 70])
xticklabels({'30','40','50','60','70'})
for i=1:4
    coeffs = polyfit(LT, Ra(i,:), 1);
    % Get fitted values
    fittedX = linspace(min(LT), max(LT), 200);
    fittedY = polyval(coeffs, fittedX);
    % Plot the fitted line
    plot(fittedX, fittedY,C(i) , 'LineWidth', 2);
end
lgd=legend('25%','50%','75%','100%','FontSize',20)
lgd.Title.FontSize = 20;

The resulted figure is as follows:

Although I only have

lgd=legend('25%','50%','75%','100%','FontSize',20)

in the script, the fitted lines are unwantedly shown in the legend box with no dedicated name:

My question:

How can I get rid of those extra lines in the legend box?

Any help is highly appredicated!

Answer 1

[Star Strider]

‘How can I get rid of those extra lines in the legend box?’

Refer only to the scatter plots by handle reference:

LT = 0.5:9.5;
Ra = randn(4,numel(LT));
C=['b','r','g','m'];
hold on
for i = 1:size(Ra,1)
    hs(i) = scatter(LT, Ra(i,:),C(i),'filled');                 % Return Handles To ‘scatter’ Objects
    coeffs = polyfit(LT, Ra(i,:), 1);
    fittedX = linspace(min(LT), max(LT), 200);
    fittedY = polyval(coeffs, fittedX);
    plot(fittedX, fittedY,C(i) , 'LineWidth', 2);
end
hold off
lgd=legend(hs, '25%','50%','75%','100%','FontSize',20);         % Use Only ‘scatter’ Objects In ‘legend’ call

Include the other lines in your code that I omitted here.

.

[CS]

It worked very well! Thanks!

[Star Strider]

As always, my pleasure!

[Rodrigo Martinez]

Dear Star Strider,

I've been working for a while with Matlab but I have always worked with my own data and figures. This time, however, my colleague sent me these figures I need to put in a paper. The legneds I need to modify are exactly the same as the ones in this post: scatter data and fit curves for which I don't need legends. Is it possible to get rid of the extra legends without needing to ask for the data to create new figures?

All the best,

[Star Strider]

@Rodrigo Martinez — I am not certain that I understand what you want.

One option to select only some data series for the legend might be to use 'DisplayName' —

LT = 0.5:9.5;
Ra = randn(4,numel(LT));
C=['b','r','g','m'];
dnv = 25:25:100;
hold on
for i = 1:size(Ra,1)
    hs(i) = scatter(LT, Ra(i,:),C(i),'filled', 'DisplayName',sprintf('%.0f%%',dnv(i)));     % Return Handles To 'scatter' Objects, Use 'DisplayName'
    coeffs = polyfit(LT, Ra(i,:), 1);
    fittedX = linspace(min(LT), max(LT), 200);
    fittedY = polyval(coeffs, fittedX);
    plot(fittedX, fittedY,C(i) , 'LineWidth', 2);
end
hold off
lgd=legend(hs([1 4]),'FontSize',20, 'Location','best');                                     % Use Only Selected 'scatter' Objects In 'legend' Call

.

Answer 2

[dpb]

If you only want the scatter points in legend, set the 'Annotation' property to not show the lines...

    plot(fittedX, fittedY,C(i) , 'LineWidth', 2,'Annotation','off');