I am trying to draw a plot containing a graph of values and an error band around them through TGraphAsymmErrors class. The problem is that the graph has a like-parabolic shape and for each X-axis value there are two Y-axis median values. This causes a problem to the top X-axis value which is on the right top of the graph. I cannot draw the error band around the top. Here is my macro

I have tried to apply many solutions that seemed to be logical (like for instance to break the initial parabolic graph to two graphs, an upper and a lower half, both ending and meeting at the biggest X-axis value 7. ), but nothing gives back a nice â€śnormally-lookingâ€ť result. Is there any idea what is going on? Thank you.

I understood whatâ€™s going on. The band drawing assumes the points are plot in in[de]creasing order along X. The 10th point is â€śgoing back in Xâ€ť â€¦ which produces this effect. Try to plot only the first 10 points and move interactively the 10th point and you will see what I mean. I do not have any easy solution right now. The only way I see is to split the band in two graphs.