Adding to a legend after each iteration

Question

I run

loglog(x,y);
legend(\'First script\');

from the first script. Then, hold on;. I run a similar second script. I see two g

Answer 1

The easiest way to deal with this is to save the handle to the legend when you create it, then whey you are ready to update the plot with a new legend with another series included, delete the legend and make a new one:

legendStrings = {'First script'};
h_legend = legend(legendStrings{:});
% ... computations, hold on and additional plot on axis
delete(h_legend);
legendStrings{end+1} = 'Second script';
h_legend = legend(legendStrings{:});
% rinse and repeat...

Usually with graphics objects, such as a textbox, I would say just reuse the object via the handle (don't delete). However, if you update the legend instead of replacing it, you have to worry about more than just the strings. The MathWorks solution referenced by zroth actually seems to address this approach!

As an alternatively to delete and create new, you can also toggle the legend on and off with legend('off'); legend('show'); as the answer in Eugenio's comment suggests.