added real project code

main
Antonio De Lucreziis 2 years ago
parent 5461990d0a
commit 7f1bbf5162

@ -1,29 +1,57 @@
# cmake_minimum_required(VERSION 3.5.0)
# set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
# # set root of location to find PETSc's pkg-config
# set(PETSC $ENV{PETSC_DIR}/$ENV{PETSC_ARCH})
# set(ENV{PKG_CONFIG_PATH} ${PETSC}/lib/pkgconfig)
# # Remove the lines below if you do not wish to have PETSc determine the compilers
# execute_process ( COMMAND pkg-config PETSc --variable=ccompiler COMMAND tr -d '\n' OUTPUT_VARIABLE C_COMPILER)
# SET(CMAKE_C_COMPILER ${C_COMPILER})
# execute_process ( COMMAND pkg-config PETSc --variable=cxxcompiler COMMAND tr -d '\n' OUTPUT_VARIABLE CXX_COMPILER)
# if (CXX_COMPILER)
# SET(CMAKE_CXX_COMPILER ${CXX_COMPILER})
# endif (CXX_COMPILER)
# execute_process ( COMMAND pkg-config PETSc --variable=fcompiler COMMAND tr -d '\n' OUTPUT_VARIABLE FORTRAN_COMPILER)
# if (FORTRAN_COMPILER)
# SET(CMAKE_Fortran_COMPILER ${FORTRAN_COMPILER})
# enable_language(Fortran)
# endif (FORTRAN_COMPILER)
# # tells CMake to build the application ex1 from the source file ex1.c
# # this must appear AFTER the compilers are set
# project(main)
# add_executable(main main.c)
# find_package(MPI REQUIRED)
# include_directories(${MPI_INCLUDE_PATH})
# find_package(PkgConfig REQUIRED)
# pkg_search_module(PETSC REQUIRED IMPORTED_TARGET PETSc)
# target_link_libraries(main PkgConfig::PETSC)
cmake_minimum_required(VERSION 3.5.0)
set(CMAKE_INSTALL_RPATH_USE_LINK_PATH TRUE)
# set root of location to find PETSc's pkg-config
# Set root of location to find PETSc's pkg-config
set(PETSC $ENV{PETSC_DIR}/$ENV{PETSC_ARCH})
set(ENV{PKG_CONFIG_PATH} ${PETSC}/lib/pkgconfig)
# Remove the lines below if you do not wish to have PETSc determine the compilers
execute_process ( COMMAND pkg-config PETSc --variable=ccompiler COMMAND tr -d '\n' OUTPUT_VARIABLE C_COMPILER)
SET(CMAKE_C_COMPILER ${C_COMPILER})
execute_process ( COMMAND pkg-config PETSc --variable=cxxcompiler COMMAND tr -d '\n' OUTPUT_VARIABLE CXX_COMPILER)
if (CXX_COMPILER)
SET(CMAKE_CXX_COMPILER ${CXX_COMPILER})
endif (CXX_COMPILER)
execute_process ( COMMAND pkg-config PETSc --variable=fcompiler COMMAND tr -d '\n' OUTPUT_VARIABLE FORTRAN_COMPILER)
if (FORTRAN_COMPILER)
SET(CMAKE_Fortran_COMPILER ${FORTRAN_COMPILER})
enable_language(Fortran)
endif (FORTRAN_COMPILER)
# tells CMake to build the application ex1 from the source file ex1.c
# this must appear AFTER the compilers are set
SET(CMAKE_C_COMPILER gcc)
SET(CMAKE_CXX_COMPILER g++)
SET(CMAKE_Fortran_COMPILER gfortran)
enable_language(Fortran)
# Tells CMake to build the application ex1 from the source file ex1.c
# This must appear AFTER the compilers are set
project(main)
add_executable(main main.c)
find_package(MPI REQUIRED)
find_package(PkgConfig REQUIRED)
pkg_search_module(PETSC REQUIRED IMPORTED_TARGET PETSc)
target_link_libraries(main PkgConfig::PETSC)
target_link_libraries(main MPI::MPI_C MPI::MPI_CXX MPI::MPI_Fortran PkgConfig::PETSC)

286
main.c

@ -1,173 +1,161 @@
/*
Laplacian in 3D. Modeled by the partial differential equation
#include <petscmat.h>
#include <petscsys.h>
#include <petscsystypes.h>
#include <petscvec.h>
#include <petscviewer.h>
- Laplacian u = 1,0 < x,y,z < 1,
#include <petscdm.h>
#include <petscdmda.h>
#include <petscksp.h>
with boundary conditions
static char help[] = "Example PETSc program\n\n";
u = 1 for x = 0, x = 1, y = 0, y = 1, z = 0, z = 1.
// extern PetscErrorCode ComputeMatrix(KSP, Mat, Mat, void *);
// extern PetscErrorCode ComputeRHS(KSP, Vec, void *);
// extern PetscErrorCode ComputeInitialSolution(DM, Vec);
This uses multigrid to solve the linear system
PetscErrorCode ArnoldiIteration(Mat A, Vec b, PetscInt n, Vec *Q, Mat H);
See src/snes/tutorials/ex50.c
int main(int argc, char **argv) {
Mat A;
Vec b;
PetscInt n, l;
Can also be run with -pc_type exotic -ksp_type fgmres
PetscFunctionBeginUser;
PetscInitialize(&argc, &argv, (char *)0, help);
PetscBool flg;
PetscOptionsGetInt(NULL, NULL, "-n", &n, &flg);
if (!flg)
n = 10;
PetscOptionsGetInt(NULL, NULL, "-l", &l, &flg);
if (!flg)
l = 4;
VecCreate(PETSC_COMM_WORLD, &b);
VecSetSizes(b, PETSC_DECIDE, n);
VecSetType(b, VECMPI);
VecSet(b, 1.0);
// VecSetValue(b, 0, 1.0, INSERT_VALUES);
MatCreate(PETSC_COMM_WORLD, &A);
MatSetSizes(A, PETSC_DECIDE, PETSC_DECIDE, n, n);
MatSetType(A, MATMPIAIJ);
// A := diag(-1, 2, -1)
for (PetscInt i = 0; i < n; i++) {
// PetscScalar v[3] = {-1.0, 2.0, -1.0};
// PetscInt col[3] = {i - 1, i, i + 1};
// PetscInt ncol = 0;
// if (i > 0) {
// col[ncol] = i - 1;
// v[ncol] = -1.0;
// ncol++;
// }
// col[ncol] = i;
// v[ncol] = 2.0;
// ncol++;
// if (i < n - 1) {
// col[ncol] = i + 1;
// v[ncol] = -1.0;
// ncol++;
// }
// MatSetValues(A, 1, &i, ncol, col, v, INSERT_VALUES);
MatSetValue(A, i, i, (PetscScalar)(i + 1), INSERT_VALUES);
}
*/
MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);
MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);
static char help[] = "Solves 3D Laplacian using multigrid.\n\n";
// MatView(A, PETSC_VIEWER_DRAW_WORLD);
MatView(A, PETSC_VIEWER_STDOUT_WORLD);
// VecView(b, PETSC_VIEWER_DRAW_WORLD);
VecView(b, PETSC_VIEWER_STDOUT_WORLD);
#include <petscdm.h>
#include <petscdmda.h>
#include <petscksp.h>
printf("Allocating memory for Krylov subspace basis\n");
extern PetscErrorCode ComputeMatrix(KSP, Mat, Mat, void *);
extern PetscErrorCode ComputeRHS(KSP, Vec, void *);
extern PetscErrorCode ComputeInitialGuess(KSP, Vec, void *);
Vec *Q;
PetscMalloc1(l, &Q);
int main(int argc, char **argv) {
KSP ksp;
PetscReal norm;
DM da;
Vec x, b, r;
Mat A;
for (PetscInt i = 0; i < l; i++) {
VecCreateMPI(PETSC_COMM_WORLD, PETSC_DECIDE, n, &Q[i]);
}
PetscFunctionBeginUser;
PetscCall(PetscInitialize(&argc, &argv, (char *)0, help));
PetscCall(KSPCreate(PETSC_COMM_WORLD, &ksp));
PetscCall(DMDACreate3d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,
DM_BOUNDARY_NONE, DMDA_STENCIL_STAR, 7, 7, 7,
PETSC_DECIDE, PETSC_DECIDE, PETSC_DECIDE, 1, 1, 0, 0,
0, &da));
PetscCall(DMSetFromOptions(da));
PetscCall(DMSetUp(da));
PetscCall(KSPSetDM(ksp, da));
PetscCall(KSPSetComputeInitialGuess(ksp, ComputeInitialGuess, NULL));
PetscCall(KSPSetComputeRHS(ksp, ComputeRHS, NULL));
PetscCall(KSPSetComputeOperators(ksp, ComputeMatrix, NULL));
PetscCall(DMDestroy(&da));
PetscCall(KSPSetFromOptions(ksp));
PetscCall(KSPSolve(ksp, NULL, NULL));
PetscCall(KSPGetSolution(ksp, &x));
PetscCall(KSPGetRhs(ksp, &b));
PetscCall(VecDuplicate(b, &r));
PetscCall(KSPGetOperators(ksp, &A, NULL));
PetscCall(MatMult(A, x, r));
PetscCall(VecAXPY(r, -1.0, b));
PetscCall(VecNorm(r, NORM_2, &norm));
PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Residual norm %g\n", (double)norm));
PetscCall(VecDestroy(&r));
PetscCall(KSPDestroy(&ksp));
PetscCall(PetscFinalize());
return 0;
}
printf("Constructing Hessenberg matrix\n");
PetscErrorCode ComputeRHS(KSP ksp, Vec b, void *ctx) {
PetscInt i, j, k, mx, my, mz, xm, ym, zm, xs, ys, zs;
DM dm;
PetscScalar Hx, Hy, Hz, HxHydHz, HyHzdHx, HxHzdHy;
PetscScalar ***barray;
Mat H;
MatCreate(PETSC_COMM_WORLD, &H);
MatSetSizes(H, PETSC_DECIDE, PETSC_DECIDE, l + 1, l);
// MatSetType(H, MATMPIAIJ);
MatSetType(H, MATDENSE);
PetscFunctionBeginUser;
PetscCall(KSPGetDM(ksp, &dm));
PetscCall(DMDAGetInfo(dm, 0, &mx, &my, &mz, 0, 0, 0, 0, 0, 0, 0, 0, 0));
Hx = 1.0 / (PetscReal)(mx - 1);
Hy = 1.0 / (PetscReal)(my - 1);
Hz = 1.0 / (PetscReal)(mz - 1);
HxHydHz = Hx * Hy / Hz;
HxHzdHy = Hx * Hz / Hy;
HyHzdHx = Hy * Hz / Hx;
PetscCall(DMDAGetCorners(dm, &xs, &ys, &zs, &xm, &ym, &zm));
PetscCall(DMDAVecGetArray(dm, b, &barray));
for (k = zs; k < zs + zm; k++) {
for (j = ys; j < ys + ym; j++) {
for (i = xs; i < xs + xm; i++) {
if (i == 0 || j == 0 || k == 0 || i == mx - 1 || j == my - 1 ||
k == mz - 1) {
barray[k][j][i] = 2.0 * (HxHydHz + HxHzdHy + HyHzdHx);
} else {
barray[k][j][i] = Hx * Hy * Hz;
}
}
}
printf("Starting Arnoldi iteration\n");
MatAssemblyBegin(H, MAT_FINAL_ASSEMBLY);
PetscCall(ArnoldiIteration(A, b, l, Q, H));
MatAssemblyEnd(H, MAT_FINAL_ASSEMBLY);
for (PetscInt i = 0; i < l + 1; i++) {
VecView(Q[i], PETSC_VIEWER_STDOUT_WORLD);
}
PetscCall(DMDAVecRestoreArray(dm, b, &barray));
PetscFunctionReturn(PETSC_SUCCESS);
MatView(H, PETSC_VIEWER_STDOUT_WORLD);
for (PetscInt i = 0; i < l + 1; i++) {
VecDestroy(&Q[i]);
}
// PetscFree(Q);
MatDestroy(&A);
VecDestroy(&b);
PetscFinalize();
return 0;
}
PetscErrorCode ComputeInitialGuess(KSP ksp, Vec b, void *ctx) {
PetscErrorCode ArnoldiIteration(Mat A, Vec b, PetscInt n, Vec *Q, Mat H) {
PetscFunctionBeginUser;
PetscCall(VecSet(b, 0));
PetscFunctionReturn(PETSC_SUCCESS);
}
PetscErrorCode ComputeMatrix(KSP ksp, Mat jac, Mat B, void *ctx) {
DM da;
PetscInt i, j, k, mx, my, mz, xm, ym, zm, xs, ys, zs;
PetscScalar v[7], Hx, Hy, Hz, HxHydHz, HyHzdHx, HxHzdHy;
MatStencil row, col[7];
PetscScalar eps = 1e-12;
PetscInt m;
VecGetSize(b, &m);
PetscFunctionBeginUser;
PetscCall(KSPGetDM(ksp, &da));
PetscCall(DMDAGetInfo(da, 0, &mx, &my, &mz, 0, 0, 0, 0, 0, 0, 0, 0, 0));
Hx = 1.0 / (PetscReal)(mx - 1);
Hy = 1.0 / (PetscReal)(my - 1);
Hz = 1.0 / (PetscReal)(mz - 1);
HxHydHz = Hx * Hy / Hz;
HxHzdHy = Hx * Hz / Hy;
HyHzdHx = Hy * Hz / Hx;
PetscCall(DMDAGetCorners(da, &xs, &ys, &zs, &xm, &ym, &zm));
for (k = zs; k < zs + zm; k++) {
for (j = ys; j < ys + ym; j++) {
for (i = xs; i < xs + xm; i++) {
row.i = i;
row.j = j;
row.k = k;
if (i == 0 || j == 0 || k == 0 || i == mx - 1 || j == my - 1 ||
k == mz - 1) {
v[0] = 2.0 * (HxHydHz + HxHzdHy + HyHzdHx);
PetscCall(MatSetValuesStencil(B, 1, &row, 1, &row, v, INSERT_VALUES));
} else {
v[0] = -HxHydHz;
col[0].i = i;
col[0].j = j;
col[0].k = k - 1;
v[1] = -HxHzdHy;
col[1].i = i;
col[1].j = j - 1;
col[1].k = k;
v[2] = -HyHzdHx;
col[2].i = i - 1;
col[2].j = j;
col[2].k = k;
v[3] = 2.0 * (HxHydHz + HxHzdHy + HyHzdHx);
col[3].i = row.i;
col[3].j = row.j;
col[3].k = row.k;
v[4] = -HyHzdHx;
col[4].i = i + 1;
col[4].j = j;
col[4].k = k;
v[5] = -HxHzdHy;
col[5].i = i;
col[5].j = j + 1;
col[5].k = k;
v[6] = -HxHydHz;
col[6].i = i;
col[6].j = j;
col[6].k = k + 1;
PetscCall(MatSetValuesStencil(B, 1, &row, 7, col, v, INSERT_VALUES));
}
}
Vec q;
MatZeroEntries(H);
VecDuplicate(b, &q);
VecCopy(b, q);
VecNormalize(q, NULL);
Q[0] = q;
for (PetscInt k = 1; k < n + 1; k++) {
Vec v;
VecDuplicate(b, &v);
MatMult(A, Q[k - 1], v);
for (PetscInt j = 0; j < k; j++) {
PetscScalar h;
VecDot(Q[j], v, &h);
MatSetValue(H, j, k - 1, h, INSERT_VALUES);
VecAXPY(v, -h, Q[j]);
}
PetscScalar h;
VecNorm(v, NORM_2, &h);
MatSetValue(H, k, k - 1, h, INSERT_VALUES);
if (h > eps) {
VecNormalize(v, NULL);
Q[k] = v;
} else {
break;
}
}
PetscCall(MatAssemblyBegin(B, MAT_FINAL_ASSEMBLY));
PetscCall(MatAssemblyEnd(B, MAT_FINAL_ASSEMBLY));
PetscFunctionReturn(PETSC_SUCCESS);
}

Loading…
Cancel
Save