Move this line to end, after copying the line objects.
legend('\alpha=0','\alpha=1/9','\alpha=1/10','location', 'northeast')
Also, it looks like each line is represented twice since your legend contains two lines for each color. Examine the outputs of h1 h2 h3 to see if there is more than 1 handle in each.
If so, and if the lines are identical, use,
legend([h1(1),h2(1),h3(1)], '\alpha=0','\alpha=1/9','\alpha=1/10','location', 'northeast')
Best Answer