How to add a legend to an existing plot?

I have a figure and it has 2 curves. When I add the legend from the 'insert menu', it only shows data1 and data2. I don't think that's enough information for my figure. So I would like to edit the legend but it won't let me. I read somewhere that it is possible to add a legend. But I am not sure how to do it for an Existing plot. So for instance, let say my figure's name is Error_vs_points, the first curve is is a solid line, the second curve is a dashed line. And I would like to add a legend that says: 'solid line': Error vs PointsA; 'Dashed line': Error vs PointsB.

 Any idea?

Answer 1

[Del]

ok, now what if I already have the figure, called Error_vs_points.fig , but I want to add a legend to it?

[Azzi Abdelmalek]

open('Error_vs_points.fig')
legend({'y1','y2'})

[Del]

Thanks!

[Azzi Abdelmalek]

Why have you accepted your answer which is in fact a question?

Answer 2

[Azzi Abdelmalek]

t=0:0.1:10;
y1=sin(t);
y2=cos(t);
plot(t,y1,'-g',t,y2,'--r')
legend({'y1','y2'})