MATLAB: How to copy over only one legend entry from each plot using copyobj()

copyobjlegend

I have three separate figure files that consist of multiple plots, but with only one legend entry each. This is because each figure consists of multiple lines of the same color.
In order to overlay each of these figures into a single figure, I input:
% Load saved figures
hgload('design_1.fig');
hgload('design_2.fig');
hgload('baseline.fig');
% Identify figures
fig1 = findobj(1,'Type','Axes');
leg1 = legend(fig1,'Design 1');
fig2 = findobj(2,'Type','Line');
leg2 = legend(fig2,'Design 2');
fig3 = findobj(3,'Type','Line');
leg3 = legend(fig3,'Baseline');
% Combine figures
copyobj(fig2,fig1);
copyobj(fig3,fig1);
However, when I do this, the legend has many extraneous entries corresponding to the lines that should not be labeled. I want my legend to only have 3 entries, exactly one from each figure. Any advice?

Best Answer

  • When creating a legend, you can specify exactly the objects you want to appear in it. In this case, you will want to recreate the legend with just one line from each series.
    % open figures;
    fig1 = openfig('design_1.fig');
    fig2 = openfig('design_2.fig');
    fig3 = openfig('baseline.fig');
    % get handles to axes and lines
    ax = findobj(fig1,'Type','Axes');
    p1 = findall(fig1,'Type','Line');
    p2 = findall(fig2,'Type','Line');
    p3 = findall(fig3,'Type','Line');
    % copy lines to same figure
    p2_new = copyobj(p2,ax);
    p3_new = copyobj(p3,ax);
    % recreate legend
    legend(ax,[p1(1),p2_new(1),p3_new(1)])