  In this paper we provide some Matlab tools for efficient vectorized coding of
the Hybridizable Discontinuous Galerkin for linear variable coefficient
reaction-diffusion problems in polyhedral domains. The resulting tools are
modular and include enhanced structures to deal with convection-diffusion
problems, plus several projections and a superconvergent postprocess of the
solution. Loops over the elements are exclusively local and, as such, have been
parallelized.
