I am wondering if it is possible to:
1. change the order of the curves in the legend after they have been plotted.
2. Indicate only the characteristics of a group of curves. For example, if I have 4 curves with different colors but two of them have circles and two of them have squares, I want a legend which only shows the circle to group the first 2 curves and the square to group the others.
Thank you in advance for your help! :)