MATLAB: Plot – add legend individually

Question

How can I update the legend of each plot individually rather than at the end of the code ?

plot(x1, y1, '-vr', 'LineWidth', linewidth, 'MarkerSize', markersize);
legend('Algorithm 1');
plot(x2, y2, '-vr', 'LineWidth', linewidth, 'MarkerSize', markersize);
legend('Algorithm 2');

The code above overwrites the legend for Algorithm 1

Answer 1

If you are working with a fairly recent version of Matlab (> R2014b I think) then you can edit an existing legend if you keep the handle to it:

figure; hAxes = gca;
plot(hAxes, x1, y1, '-vr', 'LineWidth', linewidth, 'MarkerSize', markersize);
hLegend = legend( hAxes, 'stuff' );
hold( hAxes, 'on' )
plot(hAxes, x2, y2, '-vr', 'LineWidth', linewidth, 'MarkerSize', markersize);
hLegend.String{2} = 'other stuff';

It is more efficient to do all the plots first and then put the legend up for all of them though.