Spectral element methods on unstructured meshes: which interpolation points?

In the field of spectral element approximations, the interpolation points can be chosen on the basis of different criteria, going from the minimization of the Lebesgue constant to the simplicity of the point generation procedure. In the present paper, we summarize some recent nodal distributions for a high order interpolation in the triangle. We then adopt these points as approximation points for the numerical solution of an elliptic partial differential equation on an unstructured simplicial mesh. The L (2)-norm of the approximation error is then analyzed for a model problem.