CSR assembly of the approximate Newton matrix M = I − γ·J for the 2D diffusive-wave surface operator, for use as a preconditioner matrix (hypre BoomerAMG). More...

#include "../data/MeshData.hpp"
#include "../data/SurfaceStateData.hpp"
#include <vector>

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Classes
class	openswmm::twoD::SurfaceJacobian
	Assembles M = I − γ·J (diffusion stencil) in CSR for AMG. More...

Namespaces
namespace	openswmm

namespace	openswmm::twoD

Detailed Description

CSR assembly of the approximate Newton matrix M = I − γ·J for the 2D diffusive-wave surface operator, for use as a preconditioner matrix (hypre BoomerAMG).

The Jacobi preconditioner keeps only diag(J); AMG needs the full near-symmetric M-matrix. Both use the SAME per-edge transmissivity the Jacobi psetup computes:

T_e = |edge_flux_e| / max(|h_i − h_j|, dh_floor) J_ii = −(1/A_i) Σ_e T_e (diagonal, == the Jacobi heuristic) J_ij = +(1/A_i) T_e (off-diagonal, neighbour j over e)

so the Newton matrix is M_ii = 1 + (γ/A_i) Σ_e T_e M_ij = −(γ/A_i) T_e.

The sparsity is fixed by the static mesh topology (diagonal + up to three neighbours per row), built once; only the values are refreshed each preconditioner setup.

Author: Caleb Buahin caleb.nosp@m..bua.nosp@m.hin@g.nosp@m.mail.nosp@m..com

License\n MIT License

Classes

Namespaces

Detailed Description