Abstract Mathematical physics problems are often formulated by means of the
vector analysis differential operators: divergence, gradient and rotor. For approximate
solutions of such problems it is natural to use the corresponding operator statements
for the grid problems, i.e., to use the so-called VAGO (Vector Analys Grid Operators)
method. In this paper, we discuss the possibilities of such an approach in using gen-
eral irregular grids. The vector analysis di®erence operators are constructed using
the Delaunay triangulation and the Voronoi diagrams. The truncation error and the
consistency property of the di®erence operators constructed on two types of grids are
investigated. Construction and analysis of the di®erence schemes of the VAGO method
for applied problems are illustrated by the examples of stationary and non-stationary
convection-diffusion problems. The other examples concerned the solution of the non-
stationary vector problems described by the second-order equations or the systems of
first-order equations.
A Review of Procedures for Summing Kapteyn Series in Mathematical Physics
