void
hypre_F90_IFACE(hypre_sstructvectorprint, HYPRE_SSTRUCTVECTORPRINT)
(char *filename,
hypre_F90_Obj *vector,
hypre_F90_Int *all,
hypre_F90_Int *ierr)
{
*ierr = (hypre_F90_Int)
(HYPRE_SStructVectorPrint(
(char * ) filename,
hypre_F90_PassObj (HYPRE_SStructVector, vector),
hypre_F90_PassInt (all) ) );
}
int main(int argc, char *argv[]) {
// printf("start\n");
int i, j, pi, pj;
int myid, num_procs;
int Nx, Ny, nx, ny;
//nx and ny are number of mesh cells
int solver_id;
int vis;
int ilower[2], iupper[2];
int nparts = 1;
int part = 0;
double hx, hy;
HYPRE_SStructGraph graph;
HYPRE_SStructGrid grid;
HYPRE_SStructStencil stencil;
HYPRE_SStructMatrix A;
HYPRE_ParCSRMatrix parcsr_A;
HYPRE_SStructVector b;
HYPRE_ParVector par_b;
HYPRE_SStructVector x;
HYPRE_ParVector par_x;
HYPRE_Solver solver;
// printf("variables initialized\n");
//Initialize MPI
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &myid);
MPI_Comm_size(MPI_COMM_WORLD, &num_procs);
// printf("mpi initialized\n");
// Set default problem parameters
nx = 100;
ny = 100;
Nx = 1;
solver_id = 0;
vis = 0;
// printf("defaults set\n");
// Parse command line
int arg_index = 0;
while (arg_index < argc) {
if (strcmp(argv[arg_index], "-nx") == 0) {
arg_index++;
nx = atoi(argv[arg_index++]);
// printf("nx set\n");
} else if (strcmp(argv[arg_index], "-ny") == 0) {
arg_index++;
ny = atoi(argv[arg_index++]);
// printf("ny set\n");
} else if (strcmp(argv[arg_index], "-Nx") == 0) {
arg_index++;
Nx = atoi(argv[arg_index++]);
// printf("Nx set\n");
} else if (strcmp(argv[arg_index], "-solver") == 0) {
arg_index++;
solver_id = atoi(argv[arg_index++]);
// printf("solver set\n");
} else if (strcmp(argv[arg_index], "-vis") == 0) {
arg_index++;
vis = 1;
// printf("print solution\n");
} else {
arg_index++;
// printf("plus plus\n");
}
}
// printf("command line parsed\n");
// Set up processors in grid
Ny = num_procs / Nx;
hx = 1.0 / (Nx * nx);
hy = 1.0 / (Ny * ny);
if (Ny <= Nx) {
pj = myid / Nx;
pi = myid - pj * Ny;
} else {
pi = myid / Ny;
pj = myid - pi * Nx;
}
// printf("processors assigned\n");
// Determine each processor's piece of the grid
ilower[0] = pi * nx;
ilower[1] = pj * ny;
iupper[0] = ilower[0] + nx - 1;
iupper[1] = ilower[1] + ny - 1;
// printf("upper and lowers assigned\n");
HYPRE_SStructGridCreate(MPI_COMM_WORLD, 2, nparts, &grid);
// printf("grid created\n");
HYPRE_SStructGridSetExtents(grid, part, ilower, iupper);
// printf("grid set\n");
int nvars = 1;
HYPRE_SStructVariable vartypes[1] = { HYPRE_SSTRUCT_VARIABLE_CELL };
// printf("variable type set\n");
for (i = 0; i < nparts; i++) {
HYPRE_SStructGridSetVariables(grid, i, nvars, vartypes);
}
// printf("variable type set\n");
HYPRE_SStructGridAssemble(grid);
// printf("grid assembled\n");
// Set up the stencil
HYPRE_SStructStencilCreate(2, 5, &stencil);
int entry;
int offsets[5][2] = { { 0, 0 }, { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };
int var = 0;
for (entry = 0; entry < 5; entry++) {
HYPRE_SStructStencilSetEntry(stencil, entry, offsets[entry], var);
}
// Create the graph
HYPRE_SStructGraphCreate(MPI_COMM_WORLD, grid, &graph);
int object_type = HYPRE_PARCSR;
HYPRE_SStructGraphSetObjectType(graph, object_type);
HYPRE_SStructGraphSetStencil(graph, part, var, stencil);
HYPRE_SStructGraphAssemble(graph);
int nentries = 5;
int nvalues = nentries * nx * ny;
double *values;
int stencil_indices[5];
// Setup the matrix
HYPRE_SStructMatrixCreate(MPI_COMM_WORLD, graph, &A);
HYPRE_SStructMatrixSetObjectType(A, HYPRE_PARCSR);
HYPRE_SStructMatrixInitialize(A);
// Set the matrix coefficients
values = calloc(nvalues, sizeof(double));
for (j = 0; j < nentries; j++) {
stencil_indices[j] = j;
}
// Account for differences in hx and hy
double hx2 = hx * hx;
double hy2 = hy * hy;
double hx2inv = 1 / hx2;
double hy2inv = 1 / hy2;
for (i = 0; i < nvalues; i += nentries) {
values[i] = -2.0 * hx2inv - 2.0 * hy2inv;
values[i + 1] = hx2inv;
values[i + 2] = hx2inv;
values[i + 3] = hy2inv;
values[i + 4] = hy2inv;
}
HYPRE_SStructMatrixSetBoxValues(A, part, ilower, iupper, var, nentries,
stencil_indices, values);
// Set the dirchelet boundary condition
{
int bc_ilower[2];
int bc_iupper[2];
int nentries = 1;
int nvaluesx = nentries * nx; /* number of stencil entries times the length
of one side of my grid box */
int nvaluesy = nentries * ny;
double *valuesx, *valuesy, *center_valuesx, *center_valuesy;
int stencil_indices[1];
int center_index[1];
center_index[0] = 0;
valuesx = calloc(nvaluesx, sizeof(double));
center_valuesx = calloc(nvaluesx, sizeof(double));
for (j = 0; j < nvaluesx; j++){
valuesx[j] = 0.0;
center_valuesx[j] = -hx2inv;
}
valuesy = calloc(nvaluesy, sizeof(double));
center_valuesy = calloc(nvaluesy, sizeof(double));
for (j = 0; j < nvaluesy; j++){
valuesy[j] = 0.0;
center_valuesy[j] = -hy2inv;
}
// Recall: pi and pj describe position in the processor grid
if (pj == 0) {
// Bottom row of grid points
bc_ilower[0] = pi * nx;
bc_ilower[1] = pj * ny;
bc_iupper[0] = bc_ilower[0] + nx - 1;
bc_iupper[1] = bc_ilower[1];
stencil_indices[0] = 3;
HYPRE_SStructMatrixSetBoxValues(A, part, bc_ilower, bc_iupper, var,
nentries, stencil_indices, valuesy);
HYPRE_SStructMatrixAddToBoxValues(A, part, bc_ilower, bc_iupper, var, nentries, center_index, center_valuesy);
// printf("Bottom row zeroed\n");
}
if (pj == Ny - 1) {
// upper row of grid points
bc_ilower[0] = pi * nx;
bc_ilower[1] = pj * ny + ny - 1;
bc_iupper[0] = bc_ilower[0] + ny - 1;
bc_iupper[1] = bc_ilower[1];
stencil_indices[0] = 4;
HYPRE_SStructMatrixSetBoxValues(A, part, bc_ilower, bc_iupper, var,
nentries, stencil_indices, valuesy);
HYPRE_SStructMatrixAddToBoxValues(A, part, bc_ilower, bc_iupper, var, nentries, center_index, center_valuesy);
// printf("Upper row zeroed\n");
}
if (pi == 0) {
// Left row of grid points
bc_ilower[0] = pi * nx;
bc_ilower[1] = pj * ny;
bc_iupper[0] = bc_ilower[0];
bc_iupper[1] = bc_ilower[1] + ny - 1;
stencil_indices[0] = 1;
HYPRE_SStructMatrixSetBoxValues(A, part, bc_ilower, bc_iupper, var,
nentries, stencil_indices, valuesx);
HYPRE_SStructMatrixAddToBoxValues(A, part, bc_ilower, bc_iupper, var, nentries, center_index, center_valuesx);
// printf("left collumn zeroed\n");
}
if (pi == Nx - 1) {
// Right row of grid points
bc_ilower[0] = pi * nx + nx - 1;
bc_ilower[1] = pj * ny;
bc_iupper[0] = bc_ilower[0];
bc_iupper[1] = bc_ilower[1] + ny - 1;
stencil_indices[0] = 2;
HYPRE_SStructMatrixSetBoxValues(A, part, bc_ilower, bc_iupper, var,
nentries, stencil_indices, valuesx);
HYPRE_SStructMatrixAddToBoxValues(A, part, bc_ilower, bc_iupper, var, nentries, center_index, center_valuesx);
// printf("right collumn zeroed\n");
}
free(valuesx);
free(center_valuesx);
free(valuesy);
free(center_valuesy);
}
HYPRE_SStructMatrixAssemble(A);
HYPRE_SStructMatrixGetObject(A, (void **)&parcsr_A);
// Create the right hand side and solution vectors
HYPRE_SStructVectorCreate(MPI_COMM_WORLD, grid, &b);
HYPRE_SStructVectorSetObjectType(b, HYPRE_PARCSR);
HYPRE_SStructVectorInitialize(b);
HYPRE_SStructVectorCreate(MPI_COMM_WORLD, grid, &x);
HYPRE_SStructVectorSetObjectType(x, HYPRE_PARCSR);
HYPRE_SStructVectorInitialize(x);
// Set the right hand side, exact solution, and initial guess values
double *rhs_values, *x_values, *exactsolution;
nvalues = nx * ny;
rhs_values = calloc(nvalues, sizeof(double));
x_values = calloc(nvalues, sizeof(double));
exactsolution = calloc(nvalues, sizeof(double));
// printf("RHS calculation begin\n");
for (j = 0; j < ny; j++) {
double y = (ilower[1] + j + .5) * hy;
for (i = 0; i < nx; i++) {
double x = (ilower[0] + i + .5) * hx;
rhs_values[i + j * nx] =
-8. * PI2 * sin(2. * M_PI * x) * sin(2. * M_PI * y);
exactsolution[i + j * nx] = 1.0 * sin(2. * M_PI * x) * sin(2. * M_PI * y);
x_values[i + j * nx] = 0.0;
}
}
// printf("RHS calculation ended\n");
HYPRE_SStructVectorSetBoxValues(b, part, ilower, iupper, var, rhs_values);
HYPRE_SStructVectorSetBoxValues(x, part, ilower, iupper, var, x_values);
//printf("%d %f\n", (ny*nx-1), exactsolution[ny*nx-1]);
free(x_values);
free(rhs_values);
HYPRE_SStructVectorAssemble(b);
// HYPRE_SStructVectorPrint("ss.initial.b", b, 0);
HYPRE_SStructVectorGetObject(b, (void **)&par_b);
HYPRE_SStructVectorAssemble(x);
HYPRE_SStructVectorGetObject(x, (void **)&par_x);
// Print out initial vectors
HYPRE_SStructMatrixPrint("SStructExact/ss.initial.A", A, 0);
HYPRE_SStructVectorPrint("SStructExact/ss.initial.b", b, 0);
// printf("About to solve\n");
// Select a solver
if (solver_id == 0) {
int num_iterations;
double final_res_norm;
// Create AMG solver
HYPRE_BoomerAMGCreate(&solver);
// Set solver parameters
HYPRE_BoomerAMGSetPrintLevel(solver, 3);
HYPRE_BoomerAMGSetCoarsenType(solver, 6);
HYPRE_BoomerAMGSetRelaxType(solver, 3);
HYPRE_BoomerAMGSetNumSweeps(solver, 1);
HYPRE_BoomerAMGSetMaxLevels(solver, 20);
HYPRE_BoomerAMGSetTol(solver, 1e-12);
HYPRE_BoomerAMGSetMaxIter(solver, 100);
// Set up and solve
HYPRE_BoomerAMGSetup(solver, parcsr_A, par_b, par_x);
HYPRE_BoomerAMGSolve(solver, parcsr_A, par_b, par_x);
//printf("solution obtained\n");
// Run information
HYPRE_BoomerAMGGetNumIterations(solver, &num_iterations);
HYPRE_BoomerAMGGetFinalRelativeResidualNorm(solver, &final_res_norm);
if (myid == 0) {
printf("\n");
printf("Iterations = %d\n", num_iterations);
printf("Final Relative Residual Norm = %e\n", final_res_norm);
printf("\n");
}
// Destroy solver
HYPRE_BoomerAMGDestroy(solver);
// HYPRE_ParVectorPrint(par_x, "SStructExact/ss.final.x");
char solutionfile[255];
sprintf(solutionfile, "%s.%06d", "ss.final.x", myid);
HYPRE_ParVectorPrint(par_x, solutionfile);
}
// Save the solution for visualization and L2 norm calculation
if (vis) {
FILE *file;
FILE *solution;
char filename[255];
char solutionfile[255];
sprintf(solutionfile, "%s.%06d.%d", "ss.final.x", myid, myid);
int nvalues = nx * ny;
double sum = 0;
double diff, diff2, L2;
// get the localally calculated and exact solutions)
double *values = calloc(nvalues+1, sizeof(double));
// Opens the local solution file, reads the solution to the array, values
// and closes the file.
// Opens the solution file
if ((solution = fopen(solutionfile, "rt")) == NULL) {
printf("Error: can't open output file %s\n", solutionfile);
MPI_Finalize();
exit(1);
}
// Reads the file to the array values
for (i = 0; i < nvalues + 1; i++) {
fscanf(solution, "%lf", &values[i]);
}
// Close the file
fflush(solution);
fclose(solution);
MPI_Barrier(MPI_COMM_WORLD);
// Calcluates the sum of the squared differences for the exact and numerical solutions on each processor
for (i = 1; i < nvalues + 1; i++) {
diff = values[i] - exactsolution[i-1];
diff2 = diff * diff;
if (diff2 > 10){
printf("%+6f %+6f %+6d\n", values[i], exactsolution[i-1],
i-1);
}
sum += diff2;
}
//printf("Myid is: %d and mysum is: %f\n", myid, sum);
// Ensure all processors are caught up
MPI_Barrier(MPI_COMM_WORLD);
// Passes the individual sums to processor 0 and sums them.
double *sendbuffer, *recvbuffer;
sendbuffer = calloc(1, sizeof(double));
sendbuffer[0] = sum;
recvbuffer = calloc(1, sizeof(double));
int root = 0;
int count = 1;
MPI_Reduce(sendbuffer, recvbuffer, count, MPI_DOUBLE, MPI_SUM, root, MPI_COMM_WORLD);
MPI_Barrier(MPI_COMM_WORLD);
// Calculates the L2 norm
if (myid == 0){
//printf("%f\n" , recvbuffer[myid]);
// nvalues = (nx-2)*(ny-2);
double totalvalues = nvalues * num_procs * 1.0;
L2 = sqrt(recvbuffer[0] / totalvalues);
printf("The L2 norm is %e\n", L2);
}
sprintf(filename, "%s.%06d", "vis/ss.sol", myid);
if ((file = fopen(filename, "w")) == NULL) {
printf("Error: can't open output file %s\n", filename);
MPI_Finalize();
exit(1);
}
// Save solution
for (i = 1; i < nvalues+1; i++) {
fprintf(file, "%.14e\n", values[i]);
}
// Vis Cleanup
fflush(file);
fclose(file);
free(values);
free(exactsolution);
free(sendbuffer);
free(recvbuffer);
// save global finite element mesh
if (myid == 0) {
GLVis_PrintGlobalMesh("vis/ss.mesh", Nx, Ny, nx, ny, hx, hy);
}
}
// Clean up
HYPRE_SStructMatrixDestroy(A);
HYPRE_SStructVectorDestroy(b);
HYPRE_SStructVectorDestroy(x);
// Finalize MPI*/
MPI_Finalize();
return (0);
}
