For numerically solving the Lamm equation, an overriding question is the discretization of the radial coordinate. Solutions with fine radial mesh are generally more accurate but computationally more expensive, and conversely, coarsely discretized Lamm equation solutions are quicker to calculate. Even though it has not been explicitly mentioned in the SV literature until recently (Brown and Schuck 2008) , it is easy to see that a fundamental limitation for any finiteelement algorithm with linear elements is the obligate error that occurs when approximating a smooth, curved function with piecewise linear segments. This is illustrated in Fig. 2 for a system chosen by Cao and Demeler (2005) as a benchmark in the introduction of their ASTFEM algorithm. Figure 2 shows the deviations of the curved, accurate solution from a series of linear segments with a total of only 100 (red) or 200 (blue) radius values from meniscus to bottom.