the mesh cell aspect ratio 8y16x, and does not work at all for multiple-valued surfaces having more than one y value for a given x value. This is a severe limitation because many simple shapes, such as bubbles or drops, cannot be treated. However, when it can be used, this representation is extremely efficient, requiring only a one-
dimensional storage array to record the surface height values. Likewise, the evolution of the surface only requires the updating of the one-dimensional array (see, for
example, Ref. [2]).