Created
October 23, 2023 06:40
-
-
Save ddemidov/3292c6fea940c785dc8b43461846ae45 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
rebuild: rebuild.cpp | |
mpic++ -o $@ $^ -I$(AMGCL_ROOT) -O3 -fopenmp -DNDEBUG |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
#include <vector> | |
#include <iostream> | |
#include <amgcl/backend/builtin.hpp> | |
#include <amgcl/value_type/static_matrix.hpp> | |
#include <amgcl/mpi/distributed_matrix.hpp> | |
#include <amgcl/mpi/make_solver.hpp> | |
#include <amgcl/mpi/amg.hpp> | |
#include <amgcl/mpi/coarsening/smoothed_aggregation.hpp> | |
#include <amgcl/mpi/relaxation/spai0.hpp> | |
#include <amgcl/mpi/solver/bicgstab.hpp> | |
#include <amgcl/io/binary.hpp> | |
#include <amgcl/profiler.hpp> | |
//--------------------------------------------------------------------------- | |
int main(int argc, char *argv[]) | |
{ | |
amgcl::mpi::init mpi(&argc, &argv); | |
amgcl::mpi::communicator world(MPI_COMM_WORLD); | |
int localsize = world.rank == 0 ? 3 : 2; | |
std::vector<ptrdiff_t> ptr, col; | |
std::vector<double> val; | |
ptr.push_back(0); | |
if (world.rank == 0) | |
{ | |
col.push_back(0); val.push_back(1.0); ptr.push_back(col.size()); | |
col.push_back(1); val.push_back(1.0); ptr.push_back(col.size()); | |
col.push_back(2); val.push_back(1.0); ptr.push_back(col.size()); | |
} | |
else | |
{ | |
col.push_back(3); val.push_back(1.0); ptr.push_back(col.size()); | |
col.push_back(4); val.push_back(1.0); ptr.push_back(col.size()); | |
} | |
amgcl::profiler<> prof; | |
// Declare the backend and the solver types | |
typedef amgcl::backend::builtin<double> DBackend; | |
typedef amgcl::backend::builtin<float> FBackend; | |
typedef amgcl::mpi::make_solver< | |
amgcl::mpi::amg< | |
DBackend, | |
amgcl::mpi::coarsening::smoothed_aggregation<DBackend>, | |
amgcl::mpi::relaxation::spai0<DBackend> | |
>, | |
amgcl::mpi::solver::bicgstab<DBackend> | |
> | |
Solver; | |
// Solver parameters | |
Solver::params prm; | |
prm.solver.maxiter = 200; | |
prm.precond.allow_rebuild = true; // !!! | |
std::vector<double> rhs(localsize, 1.0); | |
// Initialize the solver: | |
auto A = std::tie(localsize, ptr, col, val); | |
prof.tic("setup"); | |
Solver solve(world, A, prm); | |
prof.toc("setup"); | |
prof.tic("rebuild"); | |
solve.precond().rebuild(A); | |
prof.toc("rebuild"); | |
// Show the mini-report on the constructed solver: | |
if (world.rank == 0) | |
std::cout << solve << std::endl; | |
// Solve the system with the zero initial approximation: | |
int iters; | |
double error; | |
std::vector<double> x(localsize, 0.0); | |
prof.tic("solve"); | |
std::tie(iters, error) = solve(rhs, x); | |
prof.toc("solve"); | |
// Output the number of iterations, the relative error, | |
// and the profiling data: | |
if (world.rank == 0) | |
{ | |
std::cout | |
<< "Iterations: " << iters << std::endl | |
<< "Error: " << error << std::endl | |
<< prof << std::endl; | |
std::cout << "sol: " << std::endl; | |
for (auto &xi : x) | |
std::cout << xi << std::endl; | |
} | |
} |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment