SciFEM-Project_CoffeeMugSimulation_Celebic-Schratter/mgrid_2/README.md

gmgrid: Geometric multigrid on CPU (OpenMP)

Status on 2025-May-14

• The multigrid part is deactivated via *#undef MG in main.cpp and so only a simple Jacobi iteration is performed as solver.
• make run
• or main.GCC_ levels with number of levels in [0,7].

Data structures/implementation for GPU

• use data structures from cg_2:Framework for preconditioned solvers on GPU and CPU
• suggested: class vec from vdop_gpu.h
• suggested: class CRS_Matrix_GPU from crsmatrix_gpu.h
• use cuBLAS, cuSPARSE and more libraries whenever possible.

current code structure

• main.cpp
• binaryIO.cpp : reads CRS matrix and vector from files
• vdop.cpp : some basic vector operations on CPU, also in utils.h
• geom.cpp : reads the coarse geometry, performes mesh handling and includes mesh hierarchy
• getmatrix.cpp : compressed row storage matrix and its generation from a 2D mesh
• cuthill_mckee_ordering.cpp : graph reordering to minimize the bandwidth
• jacsolve.cpp : Jacobi solver/smoother for a linear system of equations with CRS matrix; multigrid solver
• elements.cpp : more general elements - experimental. Try with el_main.cpp
• generateCRS.cpp : Reads mesh files and generates files output with stiffness matrix (Laplace) and right hand side.