main.cpp

#include "full_multigrid.h"
#include <iostream>
#include <cstdlib>

typedef double real_t;
typedef long int idx_t;
typedef FASMultigrid multigrid_t;

int main(int argc, char **argv)
{
  srand(129);
  std::cout.precision(15);

  std::cout << "Creating multigrid class...\n";

  idx_t max_relax_iters = 5;
  idx_t relaxation_tolerance = 1e-7;

  multigrid_t::relax_t relax_scheme
    = multigrid_t::relax_t::inexact_newton_constrained;

  idx_t grid_length_x = 1, grid_length_y = 1, grid_length_z = 1;

  // set grid number in different directions;
  // usually we require: grid_num_i % (2^max_depth) == 0
  // to maintain a fast convergent rate.
  // The code can still deal with arbitrary grid number at any direction.
  idx_t grid_num_x = 64, grid_num_y = 64, grid_num_z = 64;
  idx_t max_depth = 5; // number of layers for multigrid interation

  multigrid_t multigrid (
    grid_num_x, grid_num_y, grid_num_z,
    grid_length_x, grid_length_y, grid_length_z,
    max_depth, max_relax_iters, relax_scheme,
    relaxation_tolerance);

  std::cout << "  initializing...\n";
  multigrid.setTrialSolution(0);
  multigrid.add_poly_srcs(0);
  std::cout << "  done.\n";

  std::cout << "Performing V-Cycles...\n";
  multigrid.VCycles(3);
  std::cout << "  done.\n";
  
  multigrid.printSolutionStrip(max_depth);

  return EXIT_SUCCESS;
}