How to remove legend entries from saved .fig file?

I know that legend enteries can be specified with

legend([p1 p3],{'First','Third'})

provided you have plotted it with corresponding names:

x = linspace(0,pi);
y1 = cos(x);
p1 = plot(x,y1);

hold on
y2 = cos(2*x);
p2 = plot(x,y2);

y3 = cos(3*x);
p3 = plot(x,y3);
hold off

But if I open a saved .fig file without those p1 and p2 names assigned to plots, how can I use same trick?

Thank you

UPD: I have diferrent plot 'types' (errorbars and lines)

Answer 1

[Star Strider]

One approach —

figure;
x = linspace(0,pi);
y1 = cos(x);
p1 = plot(x,y1);

hold on
y2 = cos(2*x);
p2 = plot(x,y2);

y3 = cos(3*x);
p3 = plot(x,y3);
hold off

hf = gcf;                                                           % Get Figure Handle
lines = hf.CurrentAxes.Children;                                    % Get °line' Objects From Structure
% lines = findobj(hf, 'Type','line')                                  % Find 'line' Objects (Alternative)
pv = [lines.SeriesIndex]

pv = 1×3

3 2 1

legend([lines(pv(1)) lines(pv(3))], 'First','Third', 'Location','best')     % Create 'legend' Object

To remove the legend (or at least make it invisible), use:

legend('off')

I am not certain whether you want to add it or elimiinate it.

Note — The order of the Line objects are reversed in the ‘lines’ array from the way they were originally plotted. The indexing approach makes that easier to work with.

.

[Dmitry T]

Thanks. That helped. it is easy to adapt this method to combined plots (which have scatter, plot, errorbars)

errorbar = findobj(hf, 'Type','errorbar')
lines = findobj(hf, 'Type','line')
legend([lines(2) errorbar(1)], 'name1','name2')

[Star Strider]

As always, my pleasure!

.