Add dots to close a shape, padding

Hello, I have a data of shapes (figure eight and ellipse shapes) but the shapes are not closed, I need to add dots to the data in order to close it so the shapes will be closed. for example I attach 2 mat files (figure eight and ellipse) AND also the figures.

Thanks.

[KSSV]

You want to just close or you want a smoother curve while joining? The first is simple....include the first point at the end also...it will close the curve