Exemplo n.º 1
0
int main(int argc,char **argv)
{
  SNES           snes;
  PetscErrorCode ierr;
  PetscInt       its,lits;
  PetscReal      litspit;
  DM             da;

  PetscInitialize(&argc,&argv,PETSC_NULL,help);

  /*
      Set the DMDA (grid structure) for the grids.
  */
  ierr = DMDACreate2d(PETSC_COMM_WORLD, DMDA_BOUNDARY_NONE, DMDA_BOUNDARY_NONE,DMDA_STENCIL_STAR,-5,-5,PETSC_DECIDE,PETSC_DECIDE,1,1,0,0,&da);CHKERRQ(ierr);
  ierr = DMDASNESSetFunctionLocal(da,INSERT_VALUES,(PetscErrorCode (*)(DMDALocalInfo*,void*,void*,void*))FormFunctionLocal,PETSC_NULL);CHKERRQ(ierr);
  ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);
  ierr = SNESSetDM(snes,da);CHKERRQ(ierr);
  ierr = DMDestroy(&da);CHKERRQ(ierr);

  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  ierr = SNESSolve(snes,0,0);CHKERRQ(ierr);
  ierr = SNESGetIterationNumber(snes,&its);CHKERRQ(ierr);
  ierr = SNESGetLinearSolveIterations(snes,&lits);CHKERRQ(ierr);
  litspit = ((PetscReal)lits)/((PetscReal)its);
  ierr = PetscPrintf(PETSC_COMM_WORLD,"Number of SNES iterations = %D\n",its);CHKERRQ(ierr);
  ierr = PetscPrintf(PETSC_COMM_WORLD,"Number of Linear iterations = %D\n",lits);CHKERRQ(ierr);
  ierr = PetscPrintf(PETSC_COMM_WORLD,"Average Linear its / SNES = %e\n",litspit);CHKERRQ(ierr);

  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = PetscFinalize();

  return 0;
}
Exemplo n.º 2
0
PetscErrorCode SNESReset_NASM(SNES snes)
{
  SNES_NASM      *nasm = (SNES_NASM*)snes->data;
  PetscErrorCode ierr;
  PetscInt       i;

  PetscFunctionBegin;
  for (i=0; i<nasm->n; i++) {
    if (nasm->xl) { ierr = VecDestroy(&nasm->xl[i]);CHKERRQ(ierr); }
    if (nasm->x) { ierr = VecDestroy(&nasm->x[i]);CHKERRQ(ierr); }
    if (nasm->y) { ierr = VecDestroy(&nasm->y[i]);CHKERRQ(ierr); }
    if (nasm->b) { ierr = VecDestroy(&nasm->b[i]);CHKERRQ(ierr); }

    if (nasm->subsnes) { ierr = SNESDestroy(&nasm->subsnes[i]);CHKERRQ(ierr); }
    if (nasm->oscatter) { ierr = VecScatterDestroy(&nasm->oscatter[i]);CHKERRQ(ierr); }
    if (nasm->iscatter) { ierr = VecScatterDestroy(&nasm->iscatter[i]);CHKERRQ(ierr); }
    if (nasm->gscatter) { ierr = VecScatterDestroy(&nasm->gscatter[i]);CHKERRQ(ierr); }
  }

  if (nasm->x) {ierr = PetscFree(nasm->x);CHKERRQ(ierr);}
  if (nasm->xl) {ierr = PetscFree(nasm->xl);CHKERRQ(ierr);}
  if (nasm->y) {ierr = PetscFree(nasm->y);CHKERRQ(ierr);}
  if (nasm->b) {ierr = PetscFree(nasm->b);CHKERRQ(ierr);}

  if (nasm->xinit) {ierr = VecDestroy(&nasm->xinit);CHKERRQ(ierr);}

  if (nasm->subsnes) {ierr = PetscFree(nasm->subsnes);CHKERRQ(ierr);}
  if (nasm->oscatter) {ierr = PetscFree(nasm->oscatter);CHKERRQ(ierr);}
  if (nasm->iscatter) {ierr = PetscFree(nasm->iscatter);CHKERRQ(ierr);}
  if (nasm->gscatter) {ierr = PetscFree(nasm->gscatter);CHKERRQ(ierr);}

  nasm->eventrestrictinterp = 0;
  nasm->eventsubsolve = 0;
  PetscFunctionReturn(0);
}
Exemplo n.º 3
0
int main(int argc,char **argv)
{
  PetscErrorCode ierr;
  AppCtx         ctx;
  TS             ts;
  Vec            tsrhs,U;

  ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
  ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
  ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
  ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
  ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
  ierr = VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,1,&tsrhs);CHKERRQ(ierr);
  ierr = VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,1,&U);CHKERRQ(ierr);
  ierr = TSSetRHSFunction(ts,tsrhs,TSFunction,&ctx);CHKERRQ(ierr);
  ctx.f = f;

  ierr = SNESCreate(PETSC_COMM_WORLD,&ctx.snes);CHKERRQ(ierr);
  ierr = SNESSetFromOptions(ctx.snes);CHKERRQ(ierr);
  ierr = SNESSetFunction(ctx.snes,NULL,SNESFunction,&ctx);CHKERRQ(ierr);
  ierr = SNESSetJacobian(ctx.snes,NULL,NULL,SNESComputeJacobianDefault,&ctx);CHKERRQ(ierr);
  ctx.F = F;
  ierr = VecCreateMPI(PETSC_COMM_WORLD,PETSC_DECIDE,1,&ctx.V);CHKERRQ(ierr);

  ierr = VecSet(U,1.0);CHKERRQ(ierr);
  ierr = TSSolve(ts,U);CHKERRQ(ierr);

  ierr = VecDestroy(&ctx.V);CHKERRQ(ierr);
  ierr = VecDestroy(&tsrhs);CHKERRQ(ierr);
  ierr = VecDestroy(&U);CHKERRQ(ierr);
  ierr = SNESDestroy(&ctx.snes);CHKERRQ(ierr);
  ierr = TSDestroy(&ts);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}
Exemplo n.º 4
0
/*@C
   TaoAppDefaultComputeHessian - Computes the Hessian using finite differences. 

   Collective on TAO_APPLICATION

   Input Parameters:
+  taoapp - the TAO_APPLICATION context 
.  V - compute Hessian at this point
-  ctx - the TAO_APPLICATION structure, cast to (void*)

   Output Parameters:
+  H - Hessian matrix (not altered in this routine)
.  B - newly computed Hessian matrix to use with preconditioner (generally the same as H)
-  flag - flag indicating whether the matrix sparsity structure has changed

   Options Database Key:
+  -tao_fd - Activates TaoAppDefaultComputeHessian()
-  -tao_view_hessian - view the hessian after each evaluation using PETSC_VIEWER_STDOUT_WORLD

   Level: intermediate

   Notes:
   This routine is slow and expensive, and is not currently optimized
   to take advantage of sparsity in the problem.  Although
   TaoAppDefaultComputeHessian() is not recommended for general use
   in large-scale applications, It can be useful in checking the
   correctness of a user-provided Hessian.

   Note:
   The gradient evaluation must be set using the routine TaoAppSetGradientRoutine().

.keywords: TAO_APPLICATION, finite differences, Hessian

.seealso: TaoAppSetHessianRoutine(), TaoAppDefaultComputeHessianColor(), SNESDefaultComputeJacobian(),
          TaoAppSetGradientRoutine(), TaoAppDefaultComputeGradient()

@*/
int TaoAppDefaultComputeHessian(TAO_APPLICATION taoapp,Vec V,Mat *H,Mat *B,
			     MatStructure *flag,void *ctx){
  int                  info;
  MPI_Comm             comm;
  Vec                  G;
  SNES                 snes;
  TAO_SOLVER tao;


  PetscFunctionBegin;
  info = TaoAppGetTaoSolver(taoapp, &tao);

  PetscValidHeaderSpecific(V,VEC_COOKIE,2);
  info = VecDuplicate(V,&G);CHKERRQ(info);

  info = PetscInfo(G,"TAO Using finite differences w/o coloring to compute matrix\n"); CHKERRQ(info);

  info = TaoAppComputeGradient(taoapp,V,G); CHKERRQ(info);
  tao->ngrads++;

  info = PetscObjectGetComm((PetscObject)(*H),&comm);CHKERRQ(info);
  info = SNESCreate(comm,&snes);CHKERRQ(info);

  info = SNESSetFunction(snes,G,Ftemp,taoapp);CHKERRQ(info);
  info = SNESDefaultComputeJacobian(snes,V,H,B,flag,taoapp);CHKERRQ(info);

  info = SNESDestroy(snes);CHKERRQ(info);
  
  info = VecDestroy(G);CHKERRQ(info);
  
  PetscFunctionReturn(0);
}
Exemplo n.º 5
0
PetscErrorCode SNESReset_FAS(SNES snes)
{
  PetscErrorCode ierr = 0;
  SNES_FAS * fas = (SNES_FAS *)snes->data;

  PetscFunctionBegin;
  ierr = SNESDestroy(&fas->smoothu);CHKERRQ(ierr);
  ierr = SNESDestroy(&fas->smoothd);CHKERRQ(ierr);
  ierr = MatDestroy(&fas->inject);CHKERRQ(ierr);
  ierr = MatDestroy(&fas->interpolate);CHKERRQ(ierr);
  ierr = MatDestroy(&fas->restrct);CHKERRQ(ierr);
  ierr = VecDestroy(&fas->rscale);CHKERRQ(ierr);
  if (fas->next)      ierr = SNESReset(fas->next);CHKERRQ(ierr);

  PetscFunctionReturn(0);
}
Exemplo n.º 6
0
Arquivo: atan.c Projeto: bueler/p4pdes
int main(int argc,char **argv) {
    PetscErrorCode ierr;
    SNES      snes;          // nonlinear solver context
    Vec       x, r;          // solution, residual vectors
    PetscReal x0 = 2.0;

    PetscInitialize(&argc,&argv,(char*)0,help);

    ierr = PetscOptionsBegin(PETSC_COMM_WORLD,"","options to atan","");CHKERRQ(ierr);
    ierr = PetscOptionsReal("-x0","initial value","atan.c",x0,&x0,NULL); CHKERRQ(ierr);
    ierr = PetscOptionsEnd();CHKERRQ(ierr);

    ierr = VecCreate(PETSC_COMM_WORLD,&x); CHKERRQ(ierr);
    ierr = VecSetSizes(x,PETSC_DECIDE,1); CHKERRQ(ierr);
    ierr = VecSetFromOptions(x); CHKERRQ(ierr);
    ierr = VecSet(x,x0); CHKERRQ(ierr);
    ierr = VecDuplicate(x,&r); CHKERRQ(ierr);

    ierr = SNESCreate(PETSC_COMM_WORLD,&snes); CHKERRQ(ierr);
    ierr = SNESSetFunction(snes,r,FormFunction,NULL); CHKERRQ(ierr);
    ierr = SNESSetFromOptions(snes); CHKERRQ(ierr);
    ierr = SNESSolve(snes,NULL,x); CHKERRQ(ierr);
    ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);

    VecDestroy(&x);  VecDestroy(&r);  SNESDestroy(&snes);
    PetscFinalize();
    return 0;
}
Exemplo n.º 7
0
int main(int argc, char **argv)
{
  DM             dm;   /* Problem specification */
  SNES           snes; /* Nonlinear solver */
  Vec            u;    /* Solutions */
  AppCtx         user; /* User-defined work context */
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc, &argv, NULL,help);if (ierr) return ierr;
  ierr = ProcessOptions(PETSC_COMM_WORLD, &user);CHKERRQ(ierr);
  /* Primal system */
  ierr = SNESCreate(PETSC_COMM_WORLD, &snes);CHKERRQ(ierr);
  ierr = CreateMesh(PETSC_COMM_WORLD, &user, &dm);CHKERRQ(ierr);
  ierr = SNESSetDM(snes, dm);CHKERRQ(ierr);
  ierr = SetupFE(dm, user.dim, user.simplex, "displacement", SetupPrimalProblem, &user);CHKERRQ(ierr);
  ierr = DMCreateGlobalVector(dm, &u);CHKERRQ(ierr);
  ierr = VecSet(u, 0.0);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject) u, "displacement");CHKERRQ(ierr);
  ierr = DMPlexSetSNESLocalFEM(dm, &user, &user, &user);CHKERRQ(ierr);
  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);
  ierr = DMSNESCheckFromOptions(snes, u, NULL, NULL);CHKERRQ(ierr);
  ierr = SNESSolve(snes, NULL, u);CHKERRQ(ierr);
  ierr = SNESGetSolution(snes, &u);CHKERRQ(ierr);
  ierr = VecViewFromOptions(u, NULL, "-displacement_view");CHKERRQ(ierr);
  /* Cleanup */
  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = DMDestroy(&dm);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}
Exemplo n.º 8
0
int main(int argc,char **argv)
{
  PetscErrorCode ierr;
  UserCtx        user;
  DM             red,da;
  SNES           snes;
  DM             packer;
  PetscBool      use_monitor = PETSC_FALSE;

  ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
  ierr = PetscOptionsSetFromOptions(NULL);CHKERRQ(ierr);

  /* Hardwire several options; can be changed at command line */
  ierr = PetscOptionsInsertString(NULL,common_options);CHKERRQ(ierr);
  ierr = PetscOptionsInsertString(NULL,matrix_free_options);CHKERRQ(ierr);
  ierr = PetscOptionsInsert(NULL,&argc,&argv,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsGetBool(NULL,NULL,"-use_monitor",&use_monitor,PETSC_IGNORE);CHKERRQ(ierr);

  /* Create a global vector that includes a single redundant array and two da arrays */
  ierr = DMCompositeCreate(PETSC_COMM_WORLD,&packer);CHKERRQ(ierr);
  ierr = DMRedundantCreate(PETSC_COMM_WORLD,0,1,&red);CHKERRQ(ierr);
  ierr = DMSetOptionsPrefix(red,"red_");CHKERRQ(ierr);
  ierr = DMCompositeAddDM(packer,red);CHKERRQ(ierr);
  ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,-5,2,1,NULL,&da);CHKERRQ(ierr);
  ierr = DMSetOptionsPrefix(red,"da_");CHKERRQ(ierr);
  ierr = DMCompositeAddDM(packer,(DM)da);CHKERRQ(ierr);
  ierr = DMSetApplicationContext(packer,&user);CHKERRQ(ierr);

  packer->ops->creatematrix = DMCreateMatrix_MF;

  /* create nonlinear multi-level solver */
  ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);
  ierr = SNESSetDM(snes,packer);CHKERRQ(ierr);
  ierr = SNESSetFunction(snes,NULL,ComputeFunction,NULL);CHKERRQ(ierr);
  ierr = SNESSetJacobian(snes,NULL, NULL,ComputeJacobian_MF,NULL);CHKERRQ(ierr);

  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  if (use_monitor) {
    /* create graphics windows */
    ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"u_lambda - state variables and Lagrange multipliers",-1,-1,-1,-1,&user.u_lambda_viewer);CHKERRQ(ierr);
    ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"fu_lambda - derivate w.r.t. state variables and Lagrange multipliers",-1,-1,-1,-1,&user.fu_lambda_viewer);CHKERRQ(ierr);
    ierr = SNESMonitorSet(snes,Monitor,0,0);CHKERRQ(ierr);
  }

  ierr = SNESSolve(snes,NULL,NULL);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);

  ierr = DMDestroy(&red);CHKERRQ(ierr);
  ierr = DMDestroy(&da);CHKERRQ(ierr);
  ierr = DMDestroy(&packer);CHKERRQ(ierr);
  if (use_monitor) {
    ierr = PetscViewerDestroy(&user.u_lambda_viewer);CHKERRQ(ierr);
    ierr = PetscViewerDestroy(&user.fu_lambda_viewer);CHKERRQ(ierr);
  }
  ierr = PetscFinalize();
  return ierr;
}
Exemplo n.º 9
0
Arquivo: ex67.c Projeto: lw4992/petsc
int main(int argc, char **argv)
{
  SNES           snes;                 /* nonlinear solver */
  Mat            A,J;                  /* Jacobian,preconditioner matrix */
  Vec            u,r;                  /* solution, residual vectors */
  AppCtx         user;                 /* user-defined work context */
  PetscReal      error = 0.0;          /* L_2 error in the solution */
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc, &argv, NULL, help);CHKERRQ(ierr);
  ierr = ProcessOptions(PETSC_COMM_WORLD, &user);CHKERRQ(ierr);
  ierr = SNESCreate(PETSC_COMM_WORLD, &snes);CHKERRQ(ierr);
  ierr = CreateMesh(PETSC_COMM_WORLD, &user, &user.dm);CHKERRQ(ierr);
  ierr = SNESSetDM(snes, user.dm);CHKERRQ(ierr);

  ierr = SetupExactSolution(&user);CHKERRQ(ierr);
  ierr = SetupQuadrature(&user);CHKERRQ(ierr);
  ierr = SetupSection(user.dm, &user);CHKERRQ(ierr);

  ierr = DMCreateGlobalVector(user.dm, &u);CHKERRQ(ierr);
  ierr = VecDuplicate(u, &r);CHKERRQ(ierr);

  ierr = DMSetMatType(user.dm,MATAIJ);CHKERRQ(ierr);
  ierr = DMCreateMatrix(user.dm, &J);CHKERRQ(ierr);
  A    = J;

  ierr = DMSNESSetFunctionLocal(user.dm,  (PetscErrorCode (*)(DM,Vec,Vec,void*))FormFunctionLocal,&user);CHKERRQ(ierr);
  ierr = DMSNESSetJacobianLocal(user.dm,  (PetscErrorCode (*)(DM,Vec,Mat,Mat,void*))FormJacobianLocal,&user);CHKERRQ(ierr);

  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  {
    PetscReal res;

    /* Check discretization error */
    ierr = PetscPrintf(PETSC_COMM_WORLD, "Initial guess\n");CHKERRQ(ierr);
    ierr = VecView(u, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    /* ierr = ComputeError(u, &error, &user);CHKERRQ(ierr); */
    ierr = PetscPrintf(PETSC_COMM_WORLD, "L_2 Error: %g\n", error);CHKERRQ(ierr);
    /* Check residual */
    ierr = SNESComputeFunction(snes,u,r);CHKERRQ(ierr);

    ierr = PetscPrintf(PETSC_COMM_WORLD, "Initial Residual\n");CHKERRQ(ierr);
    ierr = VecChop(r, 1.0e-10);CHKERRQ(ierr);
    ierr = VecView(r, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = VecNorm(r, NORM_2, &res);CHKERRQ(ierr);
    ierr = PetscPrintf(PETSC_COMM_WORLD, "L_2 Residual: %g\n", res);CHKERRQ(ierr);
  }

  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = VecDestroy(&r);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = DMDestroy(&user.dm);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return 0;
}
Exemplo n.º 10
0
int main(int argc,char **argv) {
  PetscErrorCode ierr;
  SNES           snes;
  KSP            ksp;
  Vec            u, uexact;
  FishCtx        user;
  DMDALocalInfo  info;
  double         errnorm;

  PetscInitialize(&argc,&argv,NULL,help);

  user.printevals = PETSC_FALSE;
  ierr = PetscOptionsBegin(PETSC_COMM_WORLD, "f3_", "options for fish3", ""); CHKERRQ(ierr);
  ierr = PetscOptionsBool("-printevals","residual and Jacobian routines report grid",
           "fish3.c",user.printevals,&user.printevals,NULL);CHKERRQ(ierr);
  ierr = PetscOptionsEnd(); CHKERRQ(ierr);

  ierr = DMDACreate3d(COMM,
               DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,
               DMDA_STENCIL_STAR,
               3,3,3,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,
               1,1,
               NULL,NULL,NULL,&(user.da)); CHKERRQ(ierr);
  ierr = DMSetFromOptions(user.da); CHKERRQ(ierr);
  ierr = DMSetUp(user.da); CHKERRQ(ierr);
  ierr = DMSetApplicationContext(user.da,&user);CHKERRQ(ierr);
  ierr = DMDAGetLocalInfo(user.da,&info); CHKERRQ(ierr);

  ierr = DMCreateGlobalVector(user.da,&u);CHKERRQ(ierr);
  ierr = VecDuplicate(u,&uexact);CHKERRQ(ierr);
  ierr = VecDuplicate(u,&(user.b));CHKERRQ(ierr);
  ierr = formExactRHS(&info,uexact,user.b,&user); CHKERRQ(ierr);

  ierr = SNESCreate(COMM,&snes); CHKERRQ(ierr);
  ierr = SNESSetDM(snes,user.da); CHKERRQ(ierr);
  ierr = DMDASNESSetFunctionLocal(user.da,INSERT_VALUES,
             (DMDASNESFunction)FormFunctionLocal,&user); CHKERRQ(ierr);
  ierr = DMDASNESSetJacobianLocal(user.da,
             (DMDASNESJacobian)FormJacobianLocal,&user); CHKERRQ(ierr);
  ierr = SNESGetKSP(snes,&ksp); CHKERRQ(ierr);
  ierr = KSPSetType(ksp,KSPCG); CHKERRQ(ierr);
  ierr = SNESSetFromOptions(snes); CHKERRQ(ierr);

  ierr = VecSet(u,0.0); CHKERRQ(ierr);
  ierr = SNESSolve(snes,NULL,u); CHKERRQ(ierr);
  ierr = VecAXPY(u,-1.0,uexact); CHKERRQ(ierr);    // u <- u + (-1.0) uexact
  ierr = VecNorm(u,NORM_INFINITY,&errnorm); CHKERRQ(ierr);
  ierr = PetscPrintf(COMM,"on %d x %d x %d grid:  error |u-uexact|_inf = %g\n",
           info.mx,info.my,info.mz,errnorm); CHKERRQ(ierr);

  VecDestroy(&u);  VecDestroy(&uexact);  VecDestroy(&(user.b));
  SNESDestroy(&snes);  DMDestroy(&(user.da));
  PetscFinalize();
  return 0;
}
Exemplo n.º 11
0
Arquivo: ex33.c Projeto: Kun-Qu/petsc
int main(int argc, char **argv)
{
  SNES           snes;   /* nonlinear solver */
  DM             da;     /* grid */
  Vec            u;      /* solution vector */
  AppCtx         user;   /* user-defined work context */
  PetscReal      t;      /* time */
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc, &argv, PETSC_NULL, help);CHKERRQ(ierr);
  /* Create solver */
  ierr = SNESCreate(PETSC_COMM_WORLD, &snes);CHKERRQ(ierr);
  /* Create mesh */
  ierr = DMDACreate1d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,-4,3,1,PETSC_NULL,&da);CHKERRQ(ierr);
  ierr = DMSetApplicationContext(da, &user);CHKERRQ(ierr);
  ierr = SNESSetDM(snes, da);CHKERRQ(ierr);
  /* Create coefficient */
  ierr = DMDACreate1d(PETSC_COMM_WORLD,DMDA_BOUNDARY_NONE,-4,1,1,PETSC_NULL,&user.cda);CHKERRQ(ierr);
  ierr = DMDASetUniformCoordinates(user.cda, 0.0, 1.0, 0.0, 1.0, 0.0, 1.0);CHKERRQ(ierr);
  ierr = DMGetGlobalVector(user.cda, &user.Kappa);CHKERRQ(ierr);
  ierr = FormPermeability(user.cda, user.Kappa, &user);CHKERRQ(ierr);
  /* Setup Problem */
  ierr = DMDASetLocalFunction(da, (DMDALocalFunction1) FormFunctionLocal);CHKERRQ(ierr);
  ierr = DMGetGlobalVector(da, &u);CHKERRQ(ierr);
  ierr = DMGetGlobalVector(da, &user.uold);CHKERRQ(ierr);
  user.sl  = 1.0;
  user.vl  = 0.1;
  user.pl  = 1.0;
  user.phi = 1.0;
  user.kappaWet   = 1.0;
  user.kappaNoWet = 0.3;
  /* Time Loop */
  user.dt = 0.1;
  for(PetscInt n = 0; n < 100; ++n, t += user.dt) {
    ierr = PetscPrintf(PETSC_COMM_WORLD, "Starting time %g\n", t);CHKERRQ(ierr);
    ierr = VecView(u, PETSC_VIEWER_DRAW_WORLD);CHKERRQ(ierr);
    /* Solve */
    ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);
    ierr = SNESSolve(snes, PETSC_NULL, u);CHKERRQ(ierr);
    /* Update */
    ierr = VecCopy(u, user.uold);CHKERRQ(ierr);

    ierr = VecView(u, PETSC_VIEWER_DRAW_WORLD);CHKERRQ(ierr);
  }
  /* Cleanup */
  ierr = DMRestoreGlobalVector(da, &u);CHKERRQ(ierr);
  ierr = DMRestoreGlobalVector(da, &user.uold);CHKERRQ(ierr);
  ierr = DMRestoreGlobalVector(user.cda, &user.Kappa);CHKERRQ(ierr);
  ierr = DMDestroy(&user.cda);CHKERRQ(ierr);
  ierr = DMDestroy(&da);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return 0;
}
Exemplo n.º 12
0
Arquivo: ex71.c Projeto: petsc/petsc
int main(int argc, char **argv)
{
  SNES           snes; /* nonlinear solver */
  DM             dm;   /* problem definition */
  Vec            u, r; /* solution and residual */
  AppCtx         user; /* user-defined work context */
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc, &argv, NULL,help);if (ierr) return ierr;
  ierr = ProcessOptions(PETSC_COMM_WORLD, &user);CHKERRQ(ierr);
  ierr = PetscBagCreate(PETSC_COMM_WORLD, sizeof(Parameter), &user.bag);CHKERRQ(ierr);
  ierr = SetupParameters(&user);CHKERRQ(ierr);
  ierr = SNESCreate(PETSC_COMM_WORLD, &snes);CHKERRQ(ierr);
  ierr = CreateMesh(PETSC_COMM_WORLD, &user, &dm);CHKERRQ(ierr);
  ierr = SNESSetDM(snes, dm);CHKERRQ(ierr);
  ierr = DMSetApplicationContext(dm, &user);CHKERRQ(ierr);
  /* Setup problem */
  ierr = PetscMalloc(2 * sizeof(void (*)(const PetscReal[], PetscScalar *, void *)), &user.exactFuncs);CHKERRQ(ierr);
  ierr = SetupDiscretization(dm, &user);CHKERRQ(ierr);
  ierr = DMPlexCreateClosureIndex(dm, NULL);CHKERRQ(ierr);

  ierr = DMCreateGlobalVector(dm, &u);CHKERRQ(ierr);
  ierr = VecDuplicate(u, &r);CHKERRQ(ierr);

  ierr = DMPlexSetSNESLocalFEM(dm,&user,&user,&user);CHKERRQ(ierr);

  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  {
    Parameter *param;
    void      *ctxs[2];

    ierr = PetscBagGetData(user.bag, (void **) &param);CHKERRQ(ierr);
    ctxs[0] = ctxs[1] = param;
    ierr = DMProjectFunction(dm, 0.0, user.exactFuncs, ctxs, INSERT_ALL_VALUES, u);CHKERRQ(ierr);
    ierr = PetscObjectSetName((PetscObject) u, "Exact Solution");CHKERRQ(ierr);
    ierr = VecViewFromOptions(u, NULL, "-exact_vec_view");CHKERRQ(ierr);
  }
  ierr = DMSNESCheckFromOptions(snes, u, NULL, NULL);CHKERRQ(ierr);
  ierr = VecSet(u, 0.0);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject) u, "Solution");CHKERRQ(ierr);
  ierr = SNESSolve(snes, NULL, u);CHKERRQ(ierr);
  ierr = VecViewFromOptions(u, NULL, "-sol_vec_view");CHKERRQ(ierr);

  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = VecDestroy(&r);CHKERRQ(ierr);
  ierr = PetscFree(user.exactFuncs);CHKERRQ(ierr);
  ierr = DMDestroy(&dm);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = PetscBagDestroy(&user.bag);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}
Exemplo n.º 13
0
int main(int argc,char **argv)
{
  PetscErrorCode ierr;
  AppCtx         ctx;
  TS             ts;
  Vec            tsrhs,U;
  IS             is;
  PetscInt       I;
  PetscMPIInt    rank;

  ierr = PetscInitialize(&argc,&argv,(char*)0,help);if (ierr) return ierr;
  ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
  ierr = TSCreate(PETSC_COMM_WORLD,&ts);CHKERRQ(ierr);
  ierr = TSSetProblemType(ts,TS_NONLINEAR);CHKERRQ(ierr);
  ierr = TSSetType(ts,TSEULER);CHKERRQ(ierr);
  ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
  ierr = VecCreateMPI(PETSC_COMM_WORLD,1,PETSC_DETERMINE,&tsrhs);CHKERRQ(ierr);
  ierr = VecCreateMPI(PETSC_COMM_WORLD,1,PETSC_DETERMINE,&U);CHKERRQ(ierr);
  ierr = TSSetRHSFunction(ts,tsrhs,TSFunction,&ctx);CHKERRQ(ierr);
  ctx.f = f;

  ierr = SNESCreate(PETSC_COMM_WORLD,&ctx.snes);CHKERRQ(ierr);
  ierr = SNESSetFromOptions(ctx.snes);CHKERRQ(ierr);
  ierr = SNESSetFunction(ctx.snes,NULL,SNESFunction,&ctx);CHKERRQ(ierr);
  ierr = SNESSetJacobian(ctx.snes,NULL,NULL,SNESComputeJacobianDefault,&ctx);CHKERRQ(ierr);
  ctx.F = F;
  ierr = VecCreateMPI(PETSC_COMM_WORLD,1,PETSC_DETERMINE,&ctx.V);CHKERRQ(ierr);

  /* Create scatters to move between separate U and V representation and UV representation of solution */
  ierr = VecCreateMPI(PETSC_COMM_WORLD,2,PETSC_DETERMINE,&ctx.UV);CHKERRQ(ierr);
  I    = 2*rank;
  ierr = ISCreateGeneral(PETSC_COMM_WORLD,1,&I,PETSC_COPY_VALUES,&is);CHKERRQ(ierr);
  ierr = VecScatterCreateWithData(U,NULL,ctx.UV,is,&ctx.scatterU);CHKERRQ(ierr);
  ierr = ISDestroy(&is);CHKERRQ(ierr);
  I    = 2*rank + 1;
  ierr = ISCreateGeneral(PETSC_COMM_WORLD,1,&I,PETSC_COPY_VALUES,&is);CHKERRQ(ierr);
  ierr = VecScatterCreateWithData(ctx.V,NULL,ctx.UV,is,&ctx.scatterV);CHKERRQ(ierr);
  ierr = ISDestroy(&is);CHKERRQ(ierr);

  ierr = VecSet(U,1.0);CHKERRQ(ierr);
  ierr = TSSolve(ts,U);CHKERRQ(ierr);

  ierr = VecDestroy(&ctx.V);CHKERRQ(ierr);
  ierr = VecDestroy(&ctx.UV);CHKERRQ(ierr);
  ierr = VecScatterDestroy(&ctx.scatterU);CHKERRQ(ierr);
  ierr = VecScatterDestroy(&ctx.scatterV);CHKERRQ(ierr);
  ierr = VecDestroy(&tsrhs);CHKERRQ(ierr);
  ierr = VecDestroy(&U);CHKERRQ(ierr);
  ierr = SNESDestroy(&ctx.snes);CHKERRQ(ierr);
  ierr = TSDestroy(&ts);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}
Exemplo n.º 14
0
int main(int argc, char **argv)
{
  DM             dm;
  SNES           snes;
  Vec            u, r;
  AppCtx         user;
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc, &argv, NULL, help);CHKERRQ(ierr);
  ierr = ProcessOptions(PETSC_COMM_WORLD, &user);CHKERRQ(ierr);
  ierr = SNESCreate(PETSC_COMM_WORLD, &snes);CHKERRQ(ierr);
  ierr = CreateMesh(PETSC_COMM_WORLD, &user, &dm);CHKERRQ(ierr);
  ierr = SNESSetDM(snes, dm);CHKERRQ(ierr);

  ierr = PetscMalloc(3 * sizeof(void (*)()), &user.exactFuncs);CHKERRQ(ierr);
  ierr = SetupDiscretization(dm, &user);CHKERRQ(ierr);

  ierr = DMCreateGlobalVector(dm, &u);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject) u, "solution");CHKERRQ(ierr);
  ierr = VecDuplicate(u, &r);CHKERRQ(ierr);
  ierr = DMPlexSetSNESLocalFEM(dm,&user,&user,&user);CHKERRQ(ierr);
  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  ierr = DMProjectFunction(dm, user.exactFuncs, NULL, INSERT_ALL_VALUES, u);CHKERRQ(ierr);
  ierr = DMSNESCheckFromOptions(snes, u, user.exactFuncs, NULL);CHKERRQ(ierr);
  if (user.runType == RUN_FULL) {
    PetscErrorCode (*initialGuess[3])(PetscInt dim, const PetscReal x[], PetscInt Nf, PetscScalar u[], void *ctx);
    PetscReal        error;

    initialGuess[0] = zero;
    initialGuess[1] = zero;
    initialGuess[2] = zero;
    ierr = DMProjectFunction(dm, initialGuess, NULL, INSERT_VALUES, u);CHKERRQ(ierr);
    ierr = VecViewFromOptions(u, NULL, "-initial_vec_view");CHKERRQ(ierr);
    ierr = DMComputeL2Diff(dm, user.exactFuncs, NULL, u, &error);CHKERRQ(ierr);
    if (error < 1.0e-11) {ierr = PetscPrintf(PETSC_COMM_WORLD, "Initial L_2 Error: < 1.0e-11\n");CHKERRQ(ierr);}
    else                 {ierr = PetscPrintf(PETSC_COMM_WORLD, "Initial L_2 Error: %g\n", error);CHKERRQ(ierr);}
    ierr = SNESSolve(snes, NULL, u);CHKERRQ(ierr);
    ierr = DMComputeL2Diff(dm, user.exactFuncs, NULL, u, &error);CHKERRQ(ierr);
    if (error < 1.0e-11) {ierr = PetscPrintf(PETSC_COMM_WORLD, "Final L_2 Error: < 1.0e-11\n");CHKERRQ(ierr);}
    else                 {ierr = PetscPrintf(PETSC_COMM_WORLD, "Final L_2 Error: %g\n", error);CHKERRQ(ierr);}
  }
  ierr = VecViewFromOptions(u, NULL, "-sol_vec_view");CHKERRQ(ierr);

  ierr = VecDestroy(&u);CHKERRQ(ierr);
  ierr = VecDestroy(&r);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = DMDestroy(&dm);CHKERRQ(ierr);
  ierr = PetscFree(user.exactFuncs);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return 0;
}
PetscNonlinearSolverImplementation::~PetscNonlinearSolverImplementation(void)
{
  PetscErrorCode ierr(0);
  try  {
    PetscBool ok;
    ierr = PetscInitialized(&ok); CHKERRXX(ierr);
    if (ok) {
      ierr = SNESDestroy(&p_snes); CHKERRXX(ierr);
    }
  } catch (...) {
    // just eat it
  }
}
Exemplo n.º 16
0
PetscErrorCode SNESDestroy_FAS(SNES snes)
{
  SNES_FAS * fas = (SNES_FAS *)snes->data;
  PetscErrorCode ierr = 0;

  PetscFunctionBegin;
  /* recursively resets and then destroys */
  ierr = SNESReset(snes);CHKERRQ(ierr);
  if (fas->next)         ierr = SNESDestroy(&fas->next);CHKERRQ(ierr);
  ierr = PetscFree(fas);CHKERRQ(ierr);

  PetscFunctionReturn(0);
}
Exemplo n.º 17
0
Arquivo: ex21.c Projeto: 00liujj/petsc
int main(int argc,char **argv)
{
  PetscErrorCode ierr;
  PetscInt       its;
  Vec            U,FU;
  SNES           snes;
  UserCtx        user;

  ierr = PetscInitialize(&argc,&argv,(char*)0,help);CHKERRQ(ierr);

  /* Create a global vector that includes a single redundant array and two da arrays */
  ierr = DMCompositeCreate(PETSC_COMM_WORLD,&user.packer);CHKERRQ(ierr);
  ierr = DMRedundantCreate(PETSC_COMM_WORLD,0,1,&user.red1);CHKERRQ(ierr);
  ierr = DMCompositeAddDM(user.packer,user.red1);CHKERRQ(ierr);
  ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,-5,1,1,NULL,&user.da1);CHKERRQ(ierr);
  ierr = DMCompositeAddDM(user.packer,user.da1);CHKERRQ(ierr);
  ierr = DMDACreate1d(PETSC_COMM_WORLD,DM_BOUNDARY_NONE,-5,1,1,NULL,&user.da2);CHKERRQ(ierr);
  ierr = DMCompositeAddDM(user.packer,user.da2);CHKERRQ(ierr);
  ierr = DMCreateGlobalVector(user.packer,&U);CHKERRQ(ierr);
  ierr = VecDuplicate(U,&FU);CHKERRQ(ierr);

  /* create graphics windows */
  ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"u - state variables",-1,-1,-1,-1,&user.u_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"lambda - Lagrange multipliers",-1,-1,-1,-1,&user.lambda_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"fu - derivate w.r.t. state variables",-1,-1,-1,-1,&user.fu_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDrawOpen(PETSC_COMM_WORLD,0,"flambda - derivate w.r.t. Lagrange multipliers",-1,-1,-1,-1,&user.flambda_viewer);CHKERRQ(ierr);


  /* create nonlinear solver */
  ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);
  ierr = SNESSetFunction(snes,FU,FormFunction,&user);CHKERRQ(ierr);
  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);
  ierr = SNESMonitorSet(snes,Monitor,&user,0);CHKERRQ(ierr);
  ierr = SNESSolve(snes,NULL,U);CHKERRQ(ierr);
  ierr = SNESGetIterationNumber(snes,&its);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);

  ierr = DMDestroy(&user.red1);CHKERRQ(ierr);
  ierr = DMDestroy(&user.da1);CHKERRQ(ierr);
  ierr = DMDestroy(&user.da2);CHKERRQ(ierr);
  ierr = DMDestroy(&user.packer);CHKERRQ(ierr);
  ierr = VecDestroy(&U);CHKERRQ(ierr);
  ierr = VecDestroy(&FU);CHKERRQ(ierr);
  ierr = PetscViewerDestroy(&user.u_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDestroy(&user.lambda_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDestroy(&user.fu_viewer);CHKERRQ(ierr);
  ierr = PetscViewerDestroy(&user.flambda_viewer);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return 0;
}
Exemplo n.º 18
0
int main(int argc,char **argv) {
    PetscErrorCode ierr;
    SNES           snes;
    Vec            u;
    DMDALocalInfo  info;
    Ctx            user;

    PetscInitialize(&argc,&argv,(char*)0,help);

    ierr = configureCtx(&user); CHKERRQ(ierr);

    ierr = DMDACreate2d(PETSC_COMM_WORLD,
                DM_BOUNDARY_NONE, DM_BOUNDARY_NONE,
                DMDA_STENCIL_STAR,
                -3,-3,
                PETSC_DECIDE,PETSC_DECIDE,
                1,1,
                NULL,NULL,
                &user.da); CHKERRQ(ierr);
    ierr = DMDASetUniformCoordinates(user.da,-1.0,1.0,-1.0,1.0,0.0,1.0); CHKERRQ(ierr);
    ierr = DMSetApplicationContext(user.da,&user); CHKERRQ(ierr);
    ierr = DMDAGetLocalInfo(user.da,&info); CHKERRQ(ierr);
    if ((info.mx < 2) || (info.my < 2)) {
        SETERRQ(PETSC_COMM_WORLD,1,"grid too coarse ... require (mx,my) > (2,2)");
    }

    ierr = DMCreateGlobalVector(user.da,&u); CHKERRQ(ierr);
    ierr = PetscObjectSetName((PetscObject)u,"u_vec");CHKERRQ(ierr);
    ierr = formInitial(&info,&user,u); CHKERRQ(ierr);

    ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);
    ierr = SNESSetDM(snes,user.da);CHKERRQ(ierr);
    ierr = DMDASNESSetFunctionLocal(user.da,INSERT_VALUES,
            (DMDASNESFunction)FormFunctionLocal,&user);CHKERRQ(ierr);
    ierr = DMDASNESSetJacobianLocal(user.da,
            (DMDASNESJacobian)FormJacobianLocal,&user);CHKERRQ(ierr);
    ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

    ierr = SNESSolve(snes,NULL,u); CHKERRQ(ierr);

    ierr = PetscPrintf(PETSC_COMM_WORLD,
         "done on %d x %d x %d grid with eps=%g ...\n",
         info.mx,info.my,info.mz,user.eps); CHKERRQ(ierr);

    VecDestroy(&u);
    SNESDestroy(&snes);  DMDestroy(&user.da);
    ierr = PetscFinalize(); CHKERRQ(ierr);
    return 0;
}
Exemplo n.º 19
0
void Solve_Distance(UserCtx	*user, int iter)
{
	SNES snes_distance;
	KSP ksp;
	PC pc;
	Vec	r;
	Mat	J;
	double norm;
	
	int	bi=0;
		
	VecDuplicate(LevelSet, &r);
	
	
	SNESCreate(PETSC_COMM_WORLD,&snes_distance);
	SNESSetFunction(snes_distance,r,FormFunction_Distance,(void	*)&user[bi]);
	MatCreateSNESMF(snes_distance, &J);
	SNESSetJacobian(snes_distance,J,J,MatMFFDComputeJacobian,(void *)&user[bi]);
		
	
	SNESSetType(snes_distance, SNESTR);			//SNESTR,SNESLS	
	double tol=1.e-2;
	SNESSetMaxLinearSolveFailures(snes_distance,10000);
	SNESSetMaxNonlinearStepFailures(snes_distance,10000);		
	SNESKSPSetUseEW(snes_distance, PETSC_TRUE);
	SNESKSPSetParametersEW(snes_distance,3,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT,PETSC_DEFAULT);
	SNESSetTolerances(snes_distance,PETSC_DEFAULT,tol,PETSC_DEFAULT,5,50000);	// snes	iter
		
	SNESGetKSP(snes_distance, &ksp);
	KSPSetType(ksp,	KSPGMRES);
	//KSPGMRESSetPreAllocateVectors(ksp);
	KSPGetPC(ksp,&pc);
	PCSetType(pc,PCNONE);
	
	//int	maxits=10;	
	int	maxits=4;	// ksp iter
	double rtol=tol, atol=PETSC_DEFAULT, dtol=PETSC_DEFAULT;
	KSPSetTolerances(ksp,rtol,atol,dtol,maxits);
	
	extern PetscErrorCode	MySNESMonitor(SNES snes,PetscInt n,PetscReal rnorm,void	*dummy);
	SNESMonitorSet(snes_distance,MySNESMonitor,PETSC_NULL,PETSC_NULL);
	SNESSolve(snes_distance, PETSC_NULL, LevelSet);
	
	SNESGetFunctionNorm(snes_distance, &norm);
	//PetscPrintf(PETSC_COMM_WORLD,	"\nDistance	SNES residual	norm=%.5e\n\n",	norm);
	VecDestroy(r);
	MatDestroy(J);
	SNESDestroy(snes_distance);
};
Exemplo n.º 20
0
/*@C
   SNESFASSetLevels - Sets the number of levels to use with FAS.
   Must be called before any other FAS routine.

   Input Parameters:
+  snes   - the snes context
.  levels - the number of levels
-  comms  - optional communicators for each level; this is to allow solving the coarser
            problems on smaller sets of processors. Use NULL_OBJECT for default in
            Fortran.

   Level: intermediate

   Notes:
     If the number of levels is one then the multigrid uses the -fas_levels prefix
  for setting the level options rather than the -fas_coarse prefix.

.keywords: FAS, MG, set, levels, multigrid

.seealso: SNESFASGetLevels()
@*/
PetscErrorCode SNESFASSetLevels(SNES snes, PetscInt levels, MPI_Comm * comms)
{
  PetscErrorCode ierr;
  PetscInt       i;
  const char     *optionsprefix;
  char           tprefix[128];
  SNES_FAS       *fas = (SNES_FAS*)snes->data;
  SNES           prevsnes;
  MPI_Comm       comm;

  PetscFunctionBegin;
  ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr);
  if (levels == fas->levels) {
    if (!comms) PetscFunctionReturn(0);
  }
  /* user has changed the number of levels; reset */
  ierr = SNESReset(snes);CHKERRQ(ierr);
  /* destroy any coarser levels if necessary */
  if (fas->next) SNESDestroy(&fas->next);CHKERRQ(ierr);
  fas->next     = NULL;
  fas->previous = NULL;
  prevsnes      = snes;
  /* setup the finest level */
  ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr);
  for (i = levels - 1; i >= 0; i--) {
    if (comms) comm = comms[i];
    fas->level  = i;
    fas->levels = levels;
    fas->fine   = snes;
    fas->next   = NULL;
    if (i > 0) {
      ierr = SNESCreate(comm, &fas->next);CHKERRQ(ierr);
      ierr = SNESGetOptionsPrefix(fas->fine, &optionsprefix);CHKERRQ(ierr);
      sprintf(tprefix,"fas_levels_%d_cycle_",(int)fas->level);
      ierr = SNESAppendOptionsPrefix(fas->next,optionsprefix);CHKERRQ(ierr);
      ierr = SNESAppendOptionsPrefix(fas->next,tprefix);CHKERRQ(ierr);
      ierr = SNESSetType(fas->next, SNESFAS);CHKERRQ(ierr);
      ierr = SNESSetTolerances(fas->next, fas->next->abstol, fas->next->rtol, fas->next->stol, fas->n_cycles, fas->next->max_funcs);CHKERRQ(ierr);
      ierr = PetscObjectIncrementTabLevel((PetscObject)fas->next, (PetscObject)snes, levels - i);CHKERRQ(ierr);

      ((SNES_FAS*)fas->next->data)->previous = prevsnes;

      prevsnes = fas->next;
      fas      = (SNES_FAS*)prevsnes->data;
    }
  }
  PetscFunctionReturn(0);
}
Exemplo n.º 21
0
void PETScNewtonKrylovSolver::deallocateSolverState()
{
    if (!d_is_initialized) return;

    IBTK_TIMER_START(t_deallocate_solver_state);

    int ierr;

    // Deallocate the linear solver and operator states only if we are not
    // re-initializing the Newton solver.
    if (!d_reinitializing_solver)
    {
        if (d_krylov_solver) d_krylov_solver->deallocateSolverState();
        if (d_J) d_J->deallocateOperatorState();
        if (d_F) d_F->deallocateOperatorState();
    }

    // Delete the solution and rhs vectors.
    PETScSAMRAIVectorReal::destroyPETScVector(d_petsc_x);
    d_petsc_x = NULL;
    d_x->freeVectorComponents();
    d_x.setNull();

    PETScSAMRAIVectorReal::destroyPETScVector(d_petsc_b);
    d_petsc_b = NULL;
    d_b->freeVectorComponents();
    d_b.setNull();

    PETScSAMRAIVectorReal::destroyPETScVector(d_petsc_r);
    d_petsc_r = NULL;
    d_r->freeVectorComponents();
    d_r.setNull();

    // Destroy the SNES solver.
    if (d_managing_petsc_snes)
    {
        ierr = SNESDestroy(&d_petsc_snes);
        IBTK_CHKERRQ(ierr);
        d_petsc_snes = NULL;
    }

    // Indicate that the solver is NOT initialized.
    d_is_initialized = false;

    IBTK_TIMER_STOP(t_deallocate_solver_state);
    return;
} // deallocateSolverState
Exemplo n.º 22
0
static PetscErrorCode SNESDestroy_Composite(SNES snes)
{
  SNES_Composite     *jac = (SNES_Composite*)snes->data;
  PetscErrorCode   ierr;
  SNES_CompositeLink next = jac->head,next_tmp;

  PetscFunctionBegin;
  ierr = SNESReset_Composite(snes);CHKERRQ(ierr);
  while (next) {
    ierr     = SNESDestroy(&next->snes);CHKERRQ(ierr);
    next_tmp = next;
    next     = next->next;
    ierr     = PetscFree(next_tmp);CHKERRQ(ierr);
  }
  ierr = PetscFree(snes->data);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemplo n.º 23
0
int main(int argc,char **argv) {
  SNES snes; Vec x,f; Mat J; DA da;
  PetscInitialize(&argc,&argv,(char *)0,help);

  DACreate1d(PETSC_COMM_WORLD,DA_NONPERIODIC,8,1,1,PETSC_NULL,&da);
  DACreateGlobalVector(da,&x); VecDuplicate(x,&f);
  DAGetMatrix(da,MATAIJ,&J);

  SNESCreate(PETSC_COMM_WORLD,&snes);
  SNESSetFunction(snes,f,ComputeFunction,da);
  SNESSetJacobian(snes,J,J,ComputeJacobian,da);
  SNESSetFromOptions(snes);
  SNESSolve(snes,PETSC_NULL,x);

  MatDestroy(J); VecDestroy(x); VecDestroy(f); SNESDestroy(snes); DADestroy(da);
  PetscFinalize();
  return 0;}
Exemplo n.º 24
0
PetscErrorCode SNESDestroy_Multiblock(SNES snes)
{
  SNES_Multiblock *mb     = (SNES_Multiblock *) snes->data;
  BlockDesc        blocks = mb->blocks, next;
  PetscErrorCode   ierr;

  PetscFunctionBegin;
  ierr = SNESReset_Multiblock(snes);CHKERRQ(ierr);
  while (blocks) {
    next = blocks->next;
    ierr = SNESDestroy(&blocks->snes);CHKERRQ(ierr);
    ierr = PetscFree(blocks->name);CHKERRQ(ierr);
    ierr = PetscFree(blocks->fields);CHKERRQ(ierr);
    ierr = PetscFree(blocks);CHKERRQ(ierr);
    blocks = next;
  }
  ierr = PetscFree(snes->data);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemplo n.º 25
0
int main(int argc, char** argv) {
  PetscInitialize( &argc, &argv, (char *)0, 0 ) ;

  int ncpus;
  MPI_Comm_size(PETSC_COMM_WORLD,&ncpus);
  if (ncpus > 1) SETERRQ(PETSC_COMM_WORLD,PETSC_ERR_SUP,
			"Example is only for sequential runs");

  Vec x, r;
  VecCreate(PETSC_COMM_WORLD, &x);
  VecSetSizes(x, PETSC_DECIDE, 2);
  VecSetFromOptions(x);
  VecDuplicate(x, &r);

  Mat J;
  MatCreate(PETSC_COMM_WORLD, &J);
  MatSetSizes(J, PETSC_DECIDE, PETSC_DECIDE, 2, 2);
  MatSetFromOptions(J);
  MatSetUp(J);


  SNES snes;
  SNESCreate(PETSC_COMM_WORLD, &snes);

  SNESSetFunction(snes, r, CalculateFunc, NULL);
  SNESSetJacobian(snes, J, J, CalculateJacobian, NULL);
  SNESSetFromOptions(snes);

  VecSet(x, 1.0);
  SNESSolve(snes, NULL, x);
  VecView(x,PETSC_VIEWER_STDOUT_WORLD);

  SNESGetFunction(snes,&r,0,0);
  VecView(r,PETSC_VIEWER_STDOUT_WORLD);

  SNESDestroy(&snes);
  MatDestroy(&J);
  VecDestroy(&r);
  VecDestroy(&x);

  PetscFinalize();
  return 0;
}
Exemplo n.º 26
0
int main(int argc,char **argv) {
    PetscErrorCode ierr;
    SNES  snes;          // nonlinear solver context
    Vec   x, r;          // solution, residual vectors

    PetscInitialize(&argc,&argv,NULL,help);
    ierr = VecCreate(PETSC_COMM_WORLD,&x); CHKERRQ(ierr);
    ierr = VecSetSizes(x,PETSC_DECIDE,2); CHKERRQ(ierr);
    ierr = VecSetFromOptions(x); CHKERRQ(ierr);
    ierr = VecSet(x,1.0); CHKERRQ(ierr);
    ierr = VecDuplicate(x,&r); CHKERRQ(ierr);

    ierr = SNESCreate(PETSC_COMM_WORLD,&snes); CHKERRQ(ierr);
    ierr = SNESSetFunction(snes,r,FormFunction,NULL); CHKERRQ(ierr);
    ierr = SNESSetFromOptions(snes); CHKERRQ(ierr);
    ierr = SNESSolve(snes,NULL,x); CHKERRQ(ierr);
    ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);

    VecDestroy(&x);  VecDestroy(&r);  SNESDestroy(&snes);
    return PetscFinalize();
}
Exemplo n.º 27
0
/*@C
   TaoDefaultComputeHessian - Computes the Hessian using finite differences.

   Collective on Tao

   Input Parameters:
+  tao   - the Tao context
.  V     - compute Hessian at this point
-  dummy - not used

   Output Parameters:
+  H - Hessian matrix (not altered in this routine)
-  B - newly computed Hessian matrix to use with preconditioner (generally the same as H)

   Options Database Key:
.  -tao_fd_hessian - activates TaoDefaultComputeHessian()

   Level: advanced

   Notes:
   This routine is slow and expensive, and is not currently optimized
   to take advantage of sparsity in the problem.  Although
   TaoDefaultComputeHessian() is not recommended for general use
   in large-scale applications, It can be useful in checking the
   correctness of a user-provided Hessian.

.seealso: TaoSetHessianRoutine(), TaoDefaultComputeHessianColor(), SNESComputeJacobianDefault(), TaoSetGradientRoutine(), TaoDefaultComputeGradient()
@*/
PetscErrorCode TaoDefaultComputeHessian(Tao tao,Vec V,Mat H,Mat B,void *dummy)
{
  PetscErrorCode ierr;
  Vec            G;
  SNES           snes;
  DM             dm;

  PetscFunctionBegin;
  ierr = VecDuplicate(V,&G);CHKERRQ(ierr);
  ierr = PetscInfo(tao,"TAO Using finite differences w/o coloring to compute Hessian matrix\n");CHKERRQ(ierr);
  ierr = TaoComputeGradient(tao,V,G);CHKERRQ(ierr);
  ierr = SNESCreate(PetscObjectComm((PetscObject)H),&snes);CHKERRQ(ierr);
  ierr = SNESSetFunction(snes,G,Fsnes,tao);CHKERRQ(ierr);
  ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
  ierr = DMShellSetGlobalVector(dm,V);CHKERRQ(ierr);
  ierr = SNESSetUp(snes);CHKERRQ(ierr);
  if (H) {
    PetscInt n,N;

    ierr = VecGetSize(V,&N);CHKERRQ(ierr);
    ierr = VecGetLocalSize(V,&n);CHKERRQ(ierr);
    ierr = MatSetSizes(H,n,n,N,N);CHKERRQ(ierr);
    ierr = MatSetUp(H);CHKERRQ(ierr);
  }
  if (B && B != H) {
    PetscInt n,N;

    ierr = VecGetSize(V,&N);CHKERRQ(ierr);
    ierr = VecGetLocalSize(V,&n);CHKERRQ(ierr);
    ierr = MatSetSizes(B,n,n,N,N);CHKERRQ(ierr);
    ierr = MatSetUp(B);CHKERRQ(ierr);
  }
  ierr = SNESComputeJacobianDefault(snes,V,H,B,NULL);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = VecDestroy(&G);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemplo n.º 28
0
/*@C
   TaoDefaultComputeHessian - Computes the Hessian using finite differences.

   Collective on Tao

   Input Parameters:
+  tao - the Tao context
.  V - compute Hessian at this point
-  dummy - not used

   Output Parameters:
+  H - Hessian matrix (not altered in this routine)
-  B - newly computed Hessian matrix to use with preconditioner (generally the same as H)

   Options Database Key:
+  -tao_fd - Activates TaoDefaultComputeHessian()
-  -tao_view_hessian - view the hessian after each evaluation using PETSC_VIEWER_STDOUT_WORLD

   Level: advanced

   Notes:
   This routine is slow and expensive, and is not currently optimized
   to take advantage of sparsity in the problem.  Although
   TaoDefaultComputeHessian() is not recommended for general use
   in large-scale applications, It can be useful in checking the
   correctness of a user-provided Hessian.

.seealso: TaoSetHessianRoutine(), TaoDefaultComputeHessianColor(), SNESComputeJacobianDefault(), TaoSetGradientRoutine(), TaoDefaultComputeGradient()

@*/
PetscErrorCode TaoDefaultComputeHessian(Tao tao,Vec V,Mat H,Mat B,void *dummy)
{
  PetscErrorCode       ierr;
  MPI_Comm             comm;
  Vec                  G;
  SNES                 snes;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(V,VEC_CLASSID,2);
  ierr = VecDuplicate(V,&G);CHKERRQ(ierr);

  ierr = PetscInfo(tao,"TAO Using finite differences w/o coloring to compute Hessian matrix\n");CHKERRQ(ierr);

  ierr = TaoComputeGradient(tao,V,G);CHKERRQ(ierr);

  ierr = PetscObjectGetComm((PetscObject)H,&comm);CHKERRQ(ierr);
  ierr = SNESCreate(comm,&snes);CHKERRQ(ierr);

  ierr = SNESSetFunction(snes,G,Fsnes,tao);CHKERRQ(ierr);
  ierr = SNESComputeJacobianDefault(snes,V,H,B,tao);CHKERRQ(ierr);
  ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = VecDestroy(&G);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Exemplo n.º 29
0
Arquivo: ex42.c Projeto: Kun-Qu/petsc
int main(int argc,char **argv)
{
  SNES           snes;         /* nonlinear solver context */
  Vec            x,r;          /* solution, residual vectors */
  Mat            J;            /* Jacobian matrix */
  PetscErrorCode ierr;
  PetscInt       its;
  PetscScalar    *xx;
  SNESConvergedReason reason;

  PetscInitialize(&argc,&argv,(char *)0,help);
  
  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     Create nonlinear solver context
     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     Create matrix and vector data structures; set corresponding routines
     - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  /*
     Create vectors for solution and nonlinear function
  */
  ierr = VecCreate(PETSC_COMM_WORLD,&x);CHKERRQ(ierr);
  ierr = VecSetSizes(x,PETSC_DECIDE,2);CHKERRQ(ierr);
  ierr = VecSetFromOptions(x);CHKERRQ(ierr);
  ierr = VecDuplicate(x,&r);CHKERRQ(ierr);

  /*
     Create Jacobian matrix data structure
  */
  ierr = MatCreate(PETSC_COMM_WORLD,&J);CHKERRQ(ierr);
  ierr = MatSetSizes(J,PETSC_DECIDE,PETSC_DECIDE,2,2);CHKERRQ(ierr);
  ierr = MatSetFromOptions(J);CHKERRQ(ierr);
  ierr = MatSetUp(J);CHKERRQ(ierr);

  /* 
     Set function evaluation routine and vector.
  */
  ierr = SNESSetFunction(snes,r,FormFunction1,PETSC_NULL);CHKERRQ(ierr);

  /* 
     Set Jacobian matrix data structure and Jacobian evaluation routine
  */
  ierr = SNESSetJacobian(snes,J,J,FormJacobian1,PETSC_NULL);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     Customize nonlinear solver; set runtime options
   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     Evaluate initial guess; then solve nonlinear system
   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
  ierr = VecGetArray(x,&xx);CHKERRQ(ierr);
  xx[0] = -1.2; xx[1] = 1.0;
  ierr = VecRestoreArray(x,&xx);CHKERRQ(ierr);

  /*
     Note: The user should initialize the vector, x, with the initial guess
     for the nonlinear solver prior to calling SNESSolve().  In particular,
     to employ an initial guess of zero, the user should explicitly set
     this vector to zero by calling VecSet().
  */

  ierr = SNESSolve(snes,PETSC_NULL,x);CHKERRQ(ierr);
  ierr = VecView(x,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = SNESGetIterationNumber(snes,&its);CHKERRQ(ierr);
  ierr = SNESGetConvergedReason(snes,&reason);CHKERRQ(ierr);
  /*
     Some systems computes a residual that is identically zero, thus converging
     due to FNORM_ABS, others converge due to FNORM_RELATIVE.  Here, we only
     report the reason if the iteration did not converge so that the tests are
     reproducible.
  */
  ierr = PetscPrintf(PETSC_COMM_WORLD,"%s number of SNES iterations = %D\n\n",reason>0?"CONVERGED":SNESConvergedReasons[reason],its);CHKERRQ(ierr);

  /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
     Free work space.  All PETSc objects should be destroyed when they
     are no longer needed.
   - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

  ierr = VecDestroy(&x);CHKERRQ(ierr); ierr = VecDestroy(&r);CHKERRQ(ierr);
  ierr = MatDestroy(&J);CHKERRQ(ierr); ierr = SNESDestroy(&snes);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return 0;
}
Exemplo n.º 30
0
int main(int argc, char **argv)
{
  MPI_Comm          comm;
  PetscMPIInt       rank;
  PetscErrorCode    ierr;
  User              user;
  PetscLogDouble       v1, v2;
  PetscInt          nplot = 0;
  char              filename1[2048], fileName[2048];
  PetscBool         set = PETSC_FALSE;
  PetscInt          steps_output;

  ierr = PetscInitialize(&argc, &argv, (char*) 0, help);CHKERRQ(ierr);
  comm = PETSC_COMM_WORLD;
  ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
  ierr = PetscNew(&user);CHKERRQ(ierr);
  ierr = PetscNew(&user->algebra);CHKERRQ(ierr);
  ierr = PetscNew(&user->model);CHKERRQ(ierr);
  ierr = PetscNew(&user->model->physics);CHKERRQ(ierr);

  Algebra   algebra = user->algebra;

  ierr = LoadOptions(comm, user);CHKERRQ(ierr);
  ierr = PetscTime(&v1);CHKERRQ(ierr);
  ierr = CreateMesh(comm, user);CHKERRQ(ierr);
  ierr = PetscTime(&v2);CHKERRQ(ierr);
  ierr = PetscPrintf(PETSC_COMM_WORLD,
		       "Read and Distribute mesh takes %f sec \n", v2 - v1);CHKERRQ(ierr);
  ierr = SetUpLocalSpace(user);CHKERRQ(ierr); //Set up the dofs of each element
  ierr = ConstructGeometryFVM(&user->facegeom, &user->cellgeom, user);CHKERRQ(ierr);

  ierr = LimiterSetup(user);CHKERRQ(ierr);

  if(user->output_solution){
  // the output file options
    ierr = PetscOptionsBegin(PETSC_COMM_WORLD,0,"Options for output solution",0);CHKERRQ(ierr);
    ierr = PetscOptionsString("-solutionfile", "solution file", "AeroSim.c", filename1,filename1, 2048, &set);CHKERRQ(ierr);
    if(!set){SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_NULL,"please use option -solutionfile to specify solution file name \n");}
    ierr = PetscOptionsInt("-steps_output", "the number of time steps between two outputs", "", steps_output, &steps_output, &set);CHKERRQ(ierr);
    if(!set){ steps_output = 1;}
    ierr = PetscOptionsEnd();CHKERRQ(ierr);
  }

  if (user->TimeIntegralMethod == EXPLICITMETHOD) {
    if(user->myownexplicitmethod){
      ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on my own routing\n");CHKERRQ(ierr);
      user->current_time = user->initial_time;
      user->current_step = 1;
      ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
      ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
      ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
      ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
      ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
      if(user->Explicit_RK2){
        ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the second order Runge Kutta method \n");CHKERRQ(ierr);
      }else{
        ierr = PetscPrintf(PETSC_COMM_WORLD,"Use the first order forward Euler method \n");CHKERRQ(ierr);
      }
      nplot = 0; //the plot step
      while(user->current_time < (user->final_time - 0.05 * user->dt)){
        user->current_time = user->current_time + user->dt;

        ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);
        PetscReal fnnorm;
        ierr = VecNorm(algebra->fn,NORM_INFINITY,&fnnorm);CHKERRQ(ierr);
        if(0){
          PetscViewer    viewer;
          ierr = OutputVTK(user->dm, "function.vtk", &viewer);CHKERRQ(ierr);
          ierr = VecView(algebra->fn, viewer);CHKERRQ(ierr);
          ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
          ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with founction norm = %g \n",
                                user->current_step, user->current_time, fnnorm);CHKERRQ(ierr);
          //break;
        }
        if(user->Explicit_RK2){
          ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);//U^n
          ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);//U^{(1)}
          ierr = FormTimeStepFunction(user, algebra, algebra->solution, algebra->fn);CHKERRQ(ierr);//f(U^{(1)})
          ierr = VecAXPY(algebra->solution, 1.0, algebra->oldsolution);CHKERRQ(ierr);//U^n + U^{(1)}
          ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);// + dt*f(U^{(1)})
          ierr = VecScale(algebra->solution, 0.5);CHKERRQ(ierr);
        }else{
          ierr = VecCopy(algebra->solution, algebra->oldsolution);CHKERRQ(ierr);
          ierr = VecAXPY(algebra->solution, user->dt, algebra->fn);CHKERRQ(ierr);
        }

        {// Monitor the solution and function norms
          PetscReal         norm;
          PetscLogDouble    space =0;
          PetscInt          size;

          ierr = VecNorm(algebra->solution,NORM_INFINITY,&norm);CHKERRQ(ierr);
          ierr = VecGetSize(algebra->solution, &size);CHKERRQ(ierr);
          norm = norm/size;
          if (norm>1.e5) {
            SETERRQ2(PETSC_COMM_WORLD, PETSC_ERR_LIB,
            "The norm of the solution is: %f (current time: %f). The explicit method is going to DIVERGE!!!", norm, user->current_time);
          }
          if (user->current_step%10==0) {
            ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with solution norm = %g and founction norm = %g \n",
                                user->current_step, user->current_time, norm, fnnorm);CHKERRQ(ierr);
          }
          ierr =  PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
//          if (user->current_step%10==0) {
//            ierr =  PetscPrintf(PETSC_COMM_WORLD,"Current space PetscMalloc()ed %g M\n",
//                                 space/(1024*1024));CHKERRQ(ierr);
//          }
        }

        { // Monitor the difference of two steps' solution
          PetscReal         norm;
          ierr = VecAXPY(algebra->oldsolution, -1, algebra->solution);CHKERRQ(ierr);
          ierr = VecNorm(algebra->oldsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
          if (user->current_step%10==0) {
            ierr = PetscPrintf(PETSC_COMM_WORLD,"Step %D at time %g with ||u_k-u_{k-1}|| = %g \n",
                              user->current_step, user->current_time, norm);CHKERRQ(ierr);
          }
          if((norm<1.e-6)||(user->current_step > user->max_time_its)) break;
        }

        // output the solution
        if (user->output_solution && (user->current_step%steps_output==0)){
          PetscViewer    viewer;

          // update file name for the current time step
          ierr = PetscSNPrintf(fileName, sizeof(fileName),"%s_%d.vtk",filename1, nplot);CHKERRQ(ierr);
          ierr = PetscPrintf(PETSC_COMM_WORLD,"Outputing solution %s (current time %f)\n", fileName, user->current_time);CHKERRQ(ierr);
          ierr = OutputVTK(user->dm, fileName, &viewer);CHKERRQ(ierr);
          ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
          ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
          nplot++;
        }

        user->current_step++;

      }
      ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
    }else{
      PetscReal         ftime;
      TS                ts;
      TSConvergedReason reason;
      PetscInt          nsteps;

      ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully explicit method based on the PETSC TS routing\n");CHKERRQ(ierr);
      ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
      ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
      ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);
      ierr = TSCreate(comm, &ts);CHKERRQ(ierr);
      ierr = TSSetType(ts, TSEULER);CHKERRQ(ierr);
      ierr = TSSetDM(ts, user->dm);CHKERRQ(ierr);
      ierr = TSMonitorSet(ts,TSMonitorFunctionError,&user,NULL);CHKERRQ(ierr);
      ierr = TSSetRHSFunction(ts, NULL, MyRHSFunction, user);CHKERRQ(ierr);
      ierr = TSSetDuration(ts, 1000, user->final_time);CHKERRQ(ierr);
      ierr = TSSetInitialTimeStep(ts, user->initial_time, user->dt);CHKERRQ(ierr);
      ierr = TSSetFromOptions(ts);CHKERRQ(ierr);
      ierr = TSSolve(ts, algebra->solution);CHKERRQ(ierr);
      ierr = TSGetSolveTime(ts, &ftime);CHKERRQ(ierr);
      ierr = TSGetTimeStepNumber(ts, &nsteps);CHKERRQ(ierr);
      ierr = TSGetConvergedReason(ts, &reason);CHKERRQ(ierr);
      ierr = PetscPrintf(PETSC_COMM_WORLD,"%s at time %g after %D steps\n",TSConvergedReasons[reason],ftime,nsteps);CHKERRQ(ierr);
      ierr = TSDestroy(&ts);CHKERRQ(ierr);
    }

    if(user->benchmark_couette) {
      ierr = DMCreateGlobalVector(user->dm, &algebra->exactsolution);CHKERRQ(ierr);
      ierr = ComputeExactSolution(user->dm, user->final_time, algebra->exactsolution, user);CHKERRQ(ierr);
    }

    if (user->output_solution){
      PetscViewer    viewer;
      ierr = OutputVTK(user->dm, "solution.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
    }

    if(user->benchmark_couette) {
      PetscViewer    viewer;
      PetscReal      norm;

      ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);

      ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
      ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
      ierr = PetscPrintf(PETSC_COMM_WORLD,"Final time at %f, Error: ||u_k-u|| = %g \n", user->final_time, norm);CHKERRQ(ierr);

      ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
    }

    ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
    ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);
    ierr = DMDestroy(&user->dm);CHKERRQ(ierr);
  } else if (user->TimeIntegralMethod == IMPLICITMETHOD) {
    ierr = PetscPrintf(PETSC_COMM_WORLD,"Using the fully implicit method\n");CHKERRQ(ierr);
    ierr =  SNESCreate(comm,&user->snes);CHKERRQ(ierr);
    ierr =  SNESSetDM(user->snes,user->dm);CHKERRQ(ierr);

    ierr = DMCreateGlobalVector(user->dm, &algebra->solution);CHKERRQ(ierr);
    ierr = VecDuplicate(algebra->solution, &algebra->oldsolution);CHKERRQ(ierr);
    ierr = VecDuplicate(algebra->solution, &algebra->f);CHKERRQ(ierr);
    ierr = VecDuplicate(algebra->solution, &algebra->fn);CHKERRQ(ierr);
    ierr = VecDuplicate(algebra->solution, &algebra->oldfn);CHKERRQ(ierr);

    ierr = PetscObjectSetName((PetscObject) algebra->solution, "solution");CHKERRQ(ierr);
    ierr = SetInitialCondition(user->dm, algebra->solution, user);CHKERRQ(ierr);

    ierr = DMSetMatType(user->dm, MATAIJ);CHKERRQ(ierr);
//    ierr = DMCreateMatrix(user->dm, &algebra->A);CHKERRQ(ierr);
    ierr = DMCreateMatrix(user->dm, &algebra->J);CHKERRQ(ierr);
    if (user->JdiffP) {
     /*Set up the preconditioner matrix*/
     ierr = DMCreateMatrix(user->dm, &algebra->P);CHKERRQ(ierr);
    }else{
     algebra->P = algebra->J;
    }

    ierr = MatSetOption(algebra->J, MAT_NEW_NONZERO_ALLOCATION_ERR, PETSC_FALSE);CHKERRQ(ierr);

    /*set nonlinear function */
    ierr =  SNESSetFunction(user->snes, algebra->f, FormFunction, (void*)user);CHKERRQ(ierr);
    /* compute Jacobian */
    ierr =  SNESSetJacobian(user->snes, algebra->J, algebra->P, FormJacobian, (void*)user);CHKERRQ(ierr);

    ierr = SNESSetFromOptions(user->snes);CHKERRQ(ierr);

    /* do the solve */
    if (user->timestep == TIMESTEP_STEADY_STATE) {
      ierr = SolveSteadyState(user);CHKERRQ(ierr);
    } else {
      ierr = SolveTimeDependent(user);CHKERRQ(ierr);
    }

    if (user->output_solution){
      PetscViewer    viewer;
      ierr = OutputVTK(user->dm, "solution.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->solution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
    }

    if(user->benchmark_couette) {
      PetscViewer    viewer;
      PetscReal      norm;

      ierr = OutputVTK(user->dm, "exact_solution.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);

      ierr = VecAXPY(algebra->exactsolution, -1, algebra->solution);CHKERRQ(ierr);
      ierr = VecNorm(algebra->exactsolution,NORM_INFINITY,&norm);CHKERRQ(ierr);
      ierr = PetscPrintf(PETSC_COMM_WORLD,"Error: ||u_k-u|| = %g \n", norm);CHKERRQ(ierr);

      ierr = OutputVTK(user->dm, "Error.vtk", &viewer);CHKERRQ(ierr);
      ierr = VecView(algebra->exactsolution, viewer);CHKERRQ(ierr);
      ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
    }

    ierr = VecDestroy(&algebra->solution);CHKERRQ(ierr);
    ierr = VecDestroy(&algebra->f);CHKERRQ(ierr);
    ierr = VecDestroy(&algebra->oldsolution);CHKERRQ(ierr);
    ierr = VecDestroy(&algebra->fn);CHKERRQ(ierr);
    ierr = VecDestroy(&algebra->oldfn);CHKERRQ(ierr);

    ierr = SNESDestroy(&user->snes);CHKERRQ(ierr);
    ierr = DMDestroy(&user->dm);CHKERRQ(ierr);

  } else {
    SETERRQ(PETSC_COMM_SELF,PETSC_ERR_USER,"WRONG option for the time integral method. Using the option '-time_integral_method 0 or 1'");
  }

  ierr = VecDestroy(&user->cellgeom);CHKERRQ(ierr);
  ierr = VecDestroy(&user->facegeom);CHKERRQ(ierr);
  ierr = DMDestroy(&user->dmGrad);CHKERRQ(ierr);

  ierr = PetscFunctionListDestroy(&LimitList);CHKERRQ(ierr);
  ierr = PetscFree(user->model->physics);CHKERRQ(ierr);
  ierr = PetscFree(user->algebra);CHKERRQ(ierr);
  ierr = PetscFree(user->model);CHKERRQ(ierr);
  ierr = PetscFree(user);CHKERRQ(ierr);

  {
    PetscLogDouble    space =0;
    ierr =  PetscMallocGetCurrentUsage(&space);CHKERRQ(ierr);
    ierr =  PetscPrintf(PETSC_COMM_WORLD,"Unfreed space at the End %g M\n", space/(1024*1024));CHKERRQ(ierr);
  }

  ierr = PetscFinalize();
  return(0);
}