SciFEM-Project_CoffeeMugSim.../mgrid_2/main.cpp

149 lines
4.5 KiB
C++

#include "geom.h"
#include "getmatrix.h"
#include "jacsolve.h"
#include "userset.h"
#include "vdop.h"
#include <cassert>
#include <chrono> // timing
#include <cmath>
#include <iostream>
#include <omp.h>
using namespace std;
using namespace std::chrono; // timing
void Test_solver(int lev, vector<int> const &nthreads, Multigrid &ggm);
int main(int argc, char **argv )
{
#undef MG
#ifndef MG
// Jacobi iteration
//int nrefine = 0;
//if (argc > 1) nrefine = atoi(argv[1]);
// generating the mesh
Mesh const mesh_c("../generate_mesh/coffee_cup.txt", "../generate_mesh/coffee_cup_sd.txt");
bool ba = mesh_c.checkObtuseAngles();
if (ba) cout << "mesh corrected" << endl;
//mesh_c.DebugEdgeBased();
//gMesh_Hierarchy ggm(mesh_c, nrefine);
//const Mesh &mesh = ggm.finest();
//mesh.Debug();
//mesh.DebugEdgeBased();
// Initializing FEM matrix !pattern! (only zero entries now)
FEM_Matrix SK(mesh_c); // CRS matrix
//SK.writeBinary("sparseMatrix.bin");
//SK.Debug();
// Initialize RHS
vector<double> fv(SK.Nrows(), 0.0); // r.h.s.
// Calculate Matrix entries
SK.CalculateLaplaceMult(fv); // matrix
//SK.Debug();
// Calculate RHS
// SK.CalculateRHS(fv, [](double x, double y) { // rhs
// return std::sin(M_PI * 2.5 * y) * (M_PI * M_PI * 2.5 * 2.5 * x * x - 2); });
SK.CalculateRHS(fv, [](double x, double y) {return 0;});
//SK.CheckRowSum();
SK.CheckMatrix();
// Initialize temperature
vector<double> uv(SK.Nrows(), 0.0); // temperature
mesh_c.Init_Solution_mult(uv, 0, [](double x, double y) -> double { return 18; }); // mug
mesh_c.Init_Solution_mult(uv, 1, [](double x, double y) -> double { return 80; }); // fluid
mesh_c.Init_Solution_mult(uv, 2, [](double x, double y) -> double { return 18; }); // air
// Apply BC
SK.ApplyRobinBC_mult(uv, fv, 18.0);
// Solve
auto exact_sol(uv);
//SK.Mult(fv,uv);
auto t3 = system_clock::now(); // start timer
// JacobiSolve(SK, fv, uv ); // solve the system of equations
auto t4 = system_clock::now(); // stop timer
auto duration = duration_cast<microseconds>(t4 - t3); // duration in microseconds
double t_diff = static_cast<double>(duration.count()) / 1e6; // overall duration in seconds
cout << "JacobiSolve: timing in sec. : " << t_diff << endl;
// Calculate error and visualize
auto [val, idx] = findLargestAbsError(exact_sol, uv, 1e+6, 100);
//mesh.Visualize(getAbsError(exact_sol, uv));
mesh_c.Visualize(uv);
#else
// multigrid iteration
int nrefine = 3;
if (argc > 1) nrefine = atoi(argv[1]);
//Multigrid ggm(Mesh("square_tiny.txt"),nrefine);
Multigrid ggm(Mesh("square_100.txt"), nrefine);
ggm.DefineOperators();
cout << "\n############# SOLVE ###############\n";
double tstart = omp_get_wtime(); // OpenMP
//ggm.JacobiSolve(my_level);
//ggm.MG_Step(my_level, 1, true, 1);
ggm.MG_Solve(2, 1e-6, 1);
double t1 = omp_get_wtime() - tstart; // OpenMP
cout << "MgSolve: timing in sec. : " << t1 << " for " << ggm.Ndofs() << " dofs" << endl;
Test_solver(nrefine - 1, {1, 2, 4, 8, 16, 32, 64, 128, 256}, ggm);
//int my_level=nrefine-1;
//const auto &ml=ggm.GetMesh(my_level);
//const auto &sl=ggm.GetSolution(my_level);
//ml.Visualize(sl);
//////ml.Visualize_paraview(sl);
////ml.Export_scicomp("level_"+to_string(my_level));
//int my_level=nrefine-1;
//const auto &mesh=ggm.GetMesh(my_level);
//const auto &uv=ggm.GetSolution(my_level);
//vector<double> exact_sol(size(uv));
//mesh.SetValues(exact_sol, [](double x, double y) -> double {
//return x * x * std::sin(2.5 * M_PI * y);
//} );
//mesh.Visualize(getAbsError(exact_sol, uv));
#endif
return 0;
}
void Test_solver(int /*lev*/, vector<int> const &nthreads, Multigrid &ggm)
{
cout << endl << endl << "-------------------------------------" << endl;
cout << "MgSolve: timing in sec. for " << ggm.Ndofs() << " dofs" << endl;
cout << "sec threads" << endl;
vector<double> mg_time(size(nthreads), -1.0);
for (size_t k = 0; k < size(nthreads); ++k) {
omp_set_num_threads(nthreads.at(k));
double tstart = omp_get_wtime();
ggm.MG_Solve(2, 1e-6, 1);
double t1 = omp_get_wtime() - tstart;
mg_time.at(k) = t1;
cout << t1 << " : " << nthreads.at(k) << endl;
}
}