Numerical Analysis Group Research Report NA-95/1

A posteriori error estimates for the cell vertex method

J. A. Mackenzie, E. Süli and E. Warnecke

Using a decomposition of the global error into a locally created part and a propagating component, we derive residual-based two-sided local a posteriori error bounds for the locally created component of the global error for Petrov-Galerkin approximations of symmetric positive systems in the sense of Friedrichs. The performance of the local error indicators is illustrated by a series of numerical experiments.