Keeping previous legend in multiple plots done by a function

Hello everybody,

I have a function, say my_plot_function , which plots simultion results. If I run my_plot_function more times, I can plot the different data on the same figure, however the legend is not kept and only the legend for the last my_plot_function run is displayed.

I want to hold not only the previous plots, but also the previous legend, and the plots are done by launching my_plot_function .

How can I keep also the previous legends, in addition to the plot?

Thanks

Patrizio

Answer 1

[Monisha Nalluru]

You can use hold method to retain the current plot while adding new plot. Legend method to add legends to axes

Here is an example of retaining legend on the axes while calling function to plot new data

function my_plot(x,y,legendName)
 plot(x,y,'DisplayName',legendName);
 legend
end

x=linspace(1,10);
y=x*2;
y1=x*3;
y2=x*4;
my_plot(x,y,'x*2');
hold on
my_plot(x,y1,'x*3');
my_plot(x,y2,'x*4');
hold off

Hope this helps!

[PatrizioGraziosi]

Unortunately this does not work in a GUI app.

I circumvented the issue by doing as follows. This way, I re-load and re-apply the legend

leg_all = findobj(gcf, 'Type', 'Legend');
leg = leg_all.String';
labels = cellstr(labels);
leg_lab = [leg ; labels] ;
A = 'data' ;
N = ~cellfun('isempty',strfind(leg_lab,A) ) ;
leg_lab(N)=[];
legend(leg_lab);

[PatrizioGraziosi]

Howvwer, this works only when I use theGUI to plot in an external figure. If I want to plot in a graph inside the GUI app, after two or three plots it automatically reset the lines...