Overview
This package contains routines to initialize reference element operators, physical mesh arrays, and connectivity arrays for nodal DG methods. The codes roughly based on Nodal Discontinuous Galerkin Methods by Hesthaven and Warburton (2007).
A short example
using StartUpDG
# polynomial degree and mesh size
N = 3
K1D = 8
# init ref element and mesh
rd = RefElemData(Tri(), N)
VXY, EToV = uniform_mesh(Tri(), K1D)
md = MeshData(VXY, EToV, rd)
# Define a function by interpolation
(; x, y ) = md
u = @. exp(-10 * (x^2 + y^2))
# Compute derivatives using geometric mapping + chain rule
(; Dr, Ds ) = rd
(; rxJ, sxJ, J ) = md
dudx = (rxJ .* (Dr * u) + sxJ .* (Ds * u)) ./ J