1c4762a1bSJed Brown! 2c4762a1bSJed Brown! Demonstrates use of DMDASNESSetFunctionLocal() from Fortran 3c4762a1bSJed Brown! 4c4762a1bSJed Brown! Note: the access to the entries of the local arrays below use the Fortran 5c4762a1bSJed Brown! convention of starting at zero. However calls to MatSetValues() start at 0. 6c4762a1bSJed Brown! Also note that you will have to map the i,j,k coordinates to the local PETSc ordering 7c4762a1bSJed Brown! before calling MatSetValuesLocal(). Often you will find that using PETSc's default 8c4762a1bSJed Brown! code for computing the Jacobian works fine and you will not need to implement 9c4762a1bSJed Brown! your own FormJacobianLocal(). 10c4762a1bSJed Brown 11c4762a1bSJed Brown program ex40f90 12c4762a1bSJed Brown 13c4762a1bSJed Brown#include <petsc/finclude/petscsnes.h> 14c4762a1bSJed Brown#include <petsc/finclude/petscdmda.h> 15c4762a1bSJed Brown use petscsnes 16c4762a1bSJed Brown use petscdmda 17c4762a1bSJed Brown implicit none 18c4762a1bSJed Brown 19c4762a1bSJed Brown SNES snes 20c4762a1bSJed Brown PetscErrorCode ierr 21c4762a1bSJed Brown DM da 22c4762a1bSJed Brown PetscInt ten,two,one 23*65ca196fSBarry Smith PetscScalar sone 24*65ca196fSBarry Smith Vec x 25c4762a1bSJed Brown external FormFunctionLocal 26c4762a1bSJed Brown 27d8606c27SBarry Smith PetscCallA(PetscInitialize(ierr)) 28c4762a1bSJed Brown ten = 10 29c4762a1bSJed Brown one = 1 30c4762a1bSJed Brown two = 2 31*65ca196fSBarry Smith sone = 1.0 32c4762a1bSJed Brown 33d8606c27SBarry Smith PetscCallA(DMDACreate2d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,DM_BOUNDARY_NONE,DMDA_STENCIL_BOX,ten,ten,PETSC_DECIDE,PETSC_DECIDE,two,one,PETSC_NULL_INTEGER,PETSC_NULL_INTEGER,da,ierr)) 34d8606c27SBarry Smith PetscCallA(DMSetFromOptions(da,ierr)) 35d8606c27SBarry Smith PetscCallA(DMSetUp(da,ierr)) 36c4762a1bSJed Brown 37c4762a1bSJed Brown! Create solver object and associate it with the unknowns (on the grid) 38c4762a1bSJed Brown 39d8606c27SBarry Smith PetscCallA(SNESCreate(PETSC_COMM_WORLD,snes,ierr)) 40d8606c27SBarry Smith PetscCallA(SNESSetDM(snes,da,ierr)) 41c4762a1bSJed Brown 42d8606c27SBarry Smith PetscCallA(DMDASNESSetFunctionLocal(da,INSERT_VALUES,FormFunctionLocal,0,ierr)) 43d8606c27SBarry Smith PetscCallA(SNESSetFromOptions(snes,ierr)) 44c4762a1bSJed Brown 45c4762a1bSJed Brown! Solve the nonlinear system 46c4762a1bSJed Brown! 47*65ca196fSBarry Smith PetscCallA(DMCreateGlobalVector(da,x,ierr)) 48*65ca196fSBarry Smith PetscCallA(VecSet(x,sone,ierr)) 49*65ca196fSBarry Smith PetscCallA(SNESSolve(snes,PETSC_NULL_VEC,x,ierr)) 50c4762a1bSJed Brown 51*65ca196fSBarry Smith PetscCallA(VecDestroy(x,ierr)) 52d8606c27SBarry Smith PetscCallA(SNESDestroy(snes,ierr)) 53d8606c27SBarry Smith PetscCallA(DMDestroy(da,ierr)) 54d8606c27SBarry Smith PetscCallA(PetscFinalize(ierr)) 55c4762a1bSJed Brown end 56c4762a1bSJed Brown 57c4762a1bSJed Brown subroutine FormFunctionLocal(in,x,f,dummy,ierr) 58c4762a1bSJed Brown implicit none 59c4762a1bSJed Brown PetscInt i,j,k,dummy 60c4762a1bSJed Brown DMDALocalInfo in(DMDA_LOCAL_INFO_SIZE) 61c4762a1bSJed Brown PetscScalar x(in(DMDA_LOCAL_INFO_DOF),XG_RANGE,YG_RANGE) 62c4762a1bSJed Brown PetscScalar f(in(DMDA_LOCAL_INFO_DOF),X_RANGE,Y_RANGE) 63c4762a1bSJed Brown PetscErrorCode ierr 64c4762a1bSJed Brown 65c4762a1bSJed Brown do i=in(DMDA_LOCAL_INFO_XS)+1,in(DMDA_LOCAL_INFO_XS)+in(DMDA_LOCAL_INFO_XM) 66c4762a1bSJed Brown do j=in(DMDA_LOCAL_INFO_YS)+1,in(DMDA_LOCAL_INFO_YS)+in(DMDA_LOCAL_INFO_YM) 67c4762a1bSJed Brown do k=1,in(DMDA_LOCAL_INFO_DOF) 68c4762a1bSJed Brown f(k,i,j) = x(k,i,j)*x(k,i,j) - 2.0 69c4762a1bSJed Brown enddo 70c4762a1bSJed Brown enddo 71c4762a1bSJed Brown enddo 72c4762a1bSJed Brown 73c4762a1bSJed Brown return 74c4762a1bSJed Brown end 75c4762a1bSJed Brown 76c4762a1bSJed Brown!/*TEST 77c4762a1bSJed Brown! 78c4762a1bSJed Brown! test: 79c4762a1bSJed Brown! args: -snes_monitor_short -snes_view -da_refine 1 -pc_type mg -pc_mg_type full -ksp_type fgmres -pc_mg_galerkin pmat 80c4762a1bSJed Brown! requires: !single 81c4762a1bSJed Brown! 82c4762a1bSJed Brown!TEST*/ 83