Fisrt of all thanks for your helping.
As a part of my thesis, I need to find all closed area in a set of data. For example as you see in the picture there is just one closed area. (Data has been attached)
I need to find JUST closed area. I tried to use polygen command, but it will connect first and last points, so will create several which causes wrong areas and wrong answers. (here says there are 3 closed area)
Do you have any Idea how can i handle it?