void PETSC_STDCALL dasetlocaljacobian_(DA *da,void (PETSC_STDCALL *jac)(DALocalInfo*,void*,void*,void*,PetscErrorCode*),PetscErrorCode *ierr)
{
PetscInt dim;
PetscObjectAllocateFortranPointers(*da,6);
*ierr = DAGetInfo(*da,&dim,0,0,0,0,0,0,0,0,0,0); if (*ierr) return;
if (dim == 2) {
((PetscObject)*da)->fortran_func_pointers[1] = (PetscVoidFunction)jac;
*ierr = DASetLocalJacobian(*da,(DALocalFunction1)ourlj2d);
} else if (dim == 3) {
((PetscObject)*da)->fortran_func_pointers[2] = (PetscVoidFunction)jac;
*ierr = DASetLocalJacobian(*da,(DALocalFunction1)ourlj3d);
} else if (dim == 1) {
((PetscObject)*da)->fortran_func_pointers[0] = (PetscVoidFunction)jac;
*ierr = DASetLocalJacobian(*da,(DALocalFunction1)ourlj1d);
} else *ierr = 1;
}
int main(int argc,char **argv)
{
PetscErrorCode ierr;
SNES snes; /* nonlinear solver */
Vec Hu,r; /* solution, residual vectors */
Mat J; /* Jacobian matrix */
AppCtx user; /* user-defined work context */
PetscInt its, i, tmpxs, tmpxm; /* iteration count, index, etc. */
PetscReal tmp1, tmp2, tmp3, tmp4, tmp5,
errnorms[2], descaleNode[2];
PetscTruth eps_set = PETSC_FALSE, dump = PETSC_FALSE, exactinitial = PETSC_FALSE,
snes_mf_set, snes_fd_set;
MatFDColoring matfdcoloring = 0;
ISColoring iscoloring;
SNESConvergedReason reason; /* Check convergence */
PetscInitialize(&argc,&argv,(char *)0,help);
ierr = MPI_Comm_rank(PETSC_COMM_WORLD, &user.rank); CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
"BODVARDSSON solves for thickness and velocity in 1D, steady ice stream\n"
" [run with -help for info and options]\n");CHKERRQ(ierr);
user.n = 3.0; /* Glen flow law exponent */
user.secpera = 31556926.0;
user.rho = 910.0; /* kg m^-3 */
user.rhow = 1028.0; /* kg m^-3 */
user.g = 9.81; /* m s^-2 */
/* ask Test N for its parameters, but only those we need to solve */
ierr = params_exactN(&(user.H0), &tmp1, &(user.xc), &tmp2, &tmp3, &tmp4, &tmp5,
&(user.Txc)); CHKERRQ(ierr);
/* regularize using strain rate of 1/xc per year */
user.epsilon = (1.0 / user.secpera) / user.xc;
/* tools for non-dimensionalizing to improve equation scaling */
user.scaleNode[0] = 1000.0; user.scaleNode[1] = 100.0 / user.secpera;
ierr = PetscOptionsTruth("-snes_mf","","",PETSC_FALSE,&snes_mf_set,NULL);CHKERRQ(ierr);
ierr = PetscOptionsTruth("-snes_fd","","",PETSC_FALSE,&snes_fd_set,NULL);CHKERRQ(ierr);
if (!snes_mf_set && !snes_fd_set) {
PetscPrintf(PETSC_COMM_WORLD,
"\n***ERROR: bodvardsson needs one or zero of '-snes_mf', '-snes_fd'***\n\n"
"USAGE FOLLOWS ...\n\n%s",help);
PetscEnd();
}
if (snes_fd_set) {
ierr = PetscPrintf(PETSC_COMM_WORLD,
" using approximate Jacobian; finite-differencing using coloring\n");
CHKERRQ(ierr);
} else if (snes_mf_set) {
ierr = PetscPrintf(PETSC_COMM_WORLD,
" matrix free; no preconditioner\n"); CHKERRQ(ierr);
} else {
ierr = PetscPrintf(PETSC_COMM_WORLD,
" true Jacobian\n"); CHKERRQ(ierr);
}
ierr = PetscOptionsBegin(PETSC_COMM_WORLD,NULL,
"bodvardsson program options",__FILE__);CHKERRQ(ierr);
{
ierr = PetscOptionsTruth("-bod_up_one","","",PETSC_FALSE,&user.upwind1,NULL);CHKERRQ(ierr);
ierr = PetscOptionsTruth("-bod_exact_init","","",PETSC_FALSE,&exactinitial,NULL);CHKERRQ(ierr);
ierr = PetscOptionsTruth("-bod_dump",
"dump out exact and approximate solution and residual, as asci","",
dump,&dump,NULL);CHKERRQ(ierr);
ierr = PetscOptionsReal("-bod_epsilon","regularization (a strain rate in units of 1/a)","",
user.epsilon * user.secpera,&user.epsilon,&eps_set);CHKERRQ(ierr);
if (eps_set) user.epsilon *= 1.0 / user.secpera;
}
ierr = PetscOptionsEnd();CHKERRQ(ierr);
/* Create machinery for parallel grid management (DA), nonlinear solver (SNES),
and Vecs for fields (solution, RHS). Note default Mx=46 grid points means
dx=10 km. Also degrees of freedom = 2 (thickness and velocity
at each point) and stencil radius = ghost width = 2 for 2nd-order upwinding. */
user.solnghostwidth = 2;
ierr = DACreate1d(PETSC_COMM_WORLD,DA_NONPERIODIC,-46,2,user.solnghostwidth,PETSC_NULL,&user.da);
CHKERRQ(ierr);
ierr = DASetUniformCoordinates(user.da,0.0,user.xc,
PETSC_NULL,PETSC_NULL,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
ierr = DASetFieldName(user.da,0,"ice thickness [non-dimensional]"); CHKERRQ(ierr);
ierr = DASetFieldName(user.da,1,"ice velocity [non-dimensional]"); CHKERRQ(ierr);
ierr = DAGetInfo(user.da,PETSC_IGNORE,&user.Mx,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,
PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE,PETSC_IGNORE);
ierr = DAGetCorners(user.da,&user.xs,PETSC_NULL,PETSC_NULL,&user.xm,PETSC_NULL,PETSC_NULL);
CHKERRQ(ierr);
user.dx = user.xc / (PetscReal)(user.Mx-1);
/* another DA for scalar parameters, with same length */
ierr = DACreate1d(PETSC_COMM_WORLD,DA_NONPERIODIC,user.Mx,1,1,PETSC_NULL,&user.scalarda);CHKERRQ(ierr);
ierr = DASetUniformCoordinates(user.scalarda,0.0,user.xc,
PETSC_NULL,PETSC_NULL,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
/* check that parallel layout of scalar DA is same as dof=2 DA */
ierr = DAGetCorners(user.scalarda,&tmpxs,PETSC_NULL,PETSC_NULL,&tmpxm,PETSC_NULL,PETSC_NULL);
CHKERRQ(ierr);
if ((tmpxs != user.xs) || (tmpxm != user.xm)) {
PetscPrintf(PETSC_COMM_SELF,
"\n***ERROR: rank %d gets different ownership range for the two DAs! ENDING ...***\n\n",
user.rank);
PetscEnd();
}
ierr = PetscPrintf(PETSC_COMM_WORLD,
" Mx = %D points, dx = %.3f m\n H0 = %.2f m, xc = %.2f km, Txc = %.5e Pa m\n",
user.Mx, user.dx, user.H0, user.xc/1000.0, user.Txc);CHKERRQ(ierr);
/* Extract/allocate global vectors from DAs and duplicate for remaining same types */
ierr = DACreateGlobalVector(user.da,&Hu);CHKERRQ(ierr);
ierr = VecSetBlockSize(Hu,2);CHKERRQ(ierr);
ierr = VecDuplicate(Hu,&r);CHKERRQ(ierr); /* inherits block size */
ierr = VecDuplicate(Hu,&user.Huexact);CHKERRQ(ierr); /* ditto */
ierr = DACreateGlobalVector(user.scalarda,&user.M);CHKERRQ(ierr);
ierr = VecDuplicate(user.M,&user.Bstag);CHKERRQ(ierr);
ierr = VecDuplicate(user.M,&user.beta);CHKERRQ(ierr);
ierr = DASetLocalFunction(user.da,(DALocalFunction1)scshell);CHKERRQ(ierr);
ierr = DASetLocalJacobian(user.da,(DALocalFunction1)BodJacobianMatrixLocal);CHKERRQ(ierr);
ierr = SNESCreate(PETSC_COMM_WORLD,&snes);CHKERRQ(ierr);
ierr = SNESSetFunction(snes,r,SNESDAFormFunction,&user);CHKERRQ(ierr);
/* setting up a matrix is only actually needed for -snes_fd case */
ierr = DAGetMatrix(user.da,MATAIJ,&J);CHKERRQ(ierr);
if (snes_fd_set) {
/* tools needed so DA can use sparse matrix for its F.D. Jacobian approx */
ierr = DAGetColoring(user.da,IS_COLORING_GLOBAL,MATAIJ,&iscoloring);CHKERRQ(ierr);
ierr = MatFDColoringCreate(J,iscoloring,&matfdcoloring);CHKERRQ(ierr);
ierr = ISColoringDestroy(iscoloring);CHKERRQ(ierr);
ierr = MatFDColoringSetFunction(matfdcoloring,
(PetscErrorCode (*)(void))SNESDAFormFunction,&user);CHKERRQ(ierr);
ierr = MatFDColoringSetFromOptions(matfdcoloring);CHKERRQ(ierr);
ierr = SNESSetJacobian(snes,J,J,SNESDefaultComputeJacobianColor,matfdcoloring);CHKERRQ(ierr);
} else {
ierr = SNESSetJacobian(snes,J,J,SNESDAComputeJacobian,&user);CHKERRQ(ierr);
}
ierr = SNESSetFromOptions(snes);CHKERRQ(ierr);
/* the the Bodvardsson (1955) exact solution allows setting M(x), B(x), beta(x), T(xc) */
ierr = FillDistributedParams(&user);CHKERRQ(ierr);
/* the exact thickness and exact ice velocity (user.uHexact) are known from Bodvardsson (1955) */
ierr = FillExactSoln(&user); CHKERRQ(ierr);
if (exactinitial) {
ierr = PetscPrintf(PETSC_COMM_WORLD," using exact solution as initial guess\n");
CHKERRQ(ierr);
/* the initial guess is the exact continuum solution */
ierr = VecCopy(user.Huexact,Hu); CHKERRQ(ierr);
} else {
ierr = FillInitial(&user, &Hu); CHKERRQ(ierr);
}
/************ SOLVE NONLINEAR SYSTEM ************/
/* recall that RHS r is used internally by KSP, and is set by the SNES */
for (i = 0; i < 2; i++) descaleNode[i] = 1.0 / user.scaleNode[i];
ierr = VecStrideScaleAll(Hu,descaleNode); CHKERRQ(ierr); /* de-dimensionalize initial guess */
ierr = SNESSolve(snes,PETSC_NULL,Hu);CHKERRQ(ierr);
ierr = VecStrideScaleAll(Hu,user.scaleNode); CHKERRQ(ierr); /* put back in "real" scale */
ierr = SNESGetIterationNumber(snes,&its);CHKERRQ(ierr);
ierr = SNESGetConvergedReason(snes,&reason);CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
" %s Number of Newton iterations = %D\n",
SNESConvergedReasons[reason],its);CHKERRQ(ierr);
if (dump) {
ierr = PetscPrintf(PETSC_COMM_WORLD,
" viewing combined result Hu\n");CHKERRQ(ierr);
ierr = VecView(Hu,PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
" viewing combined exact result Huexact\n");CHKERRQ(ierr);
ierr = VecView(user.Huexact,PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
" viewing final combined residual at Hu\n");CHKERRQ(ierr);
ierr = VecView(r,PETSC_VIEWER_STDOUT_WORLD); CHKERRQ(ierr);
}
/* evaluate error relative to exact solution */
ierr = VecAXPY(Hu,-1.0,user.Huexact); CHKERRQ(ierr); /* Hu = - Huexact + Hu */
ierr = VecStrideNormAll(Hu,NORM_INFINITY,errnorms); CHKERRQ(ierr);
ierr = PetscPrintf(PETSC_COMM_WORLD,
"(dx,errHinf,erruinf) %.3f %.4e %.4e\n",
user.dx,errnorms[0],errnorms[1]*user.secpera);CHKERRQ(ierr);
ierr = VecDestroy(Hu);CHKERRQ(ierr);
ierr = VecDestroy(r);CHKERRQ(ierr);
ierr = VecDestroy(user.Huexact);CHKERRQ(ierr);
ierr = VecDestroy(user.M);CHKERRQ(ierr);
ierr = VecDestroy(user.Bstag);CHKERRQ(ierr);
ierr = VecDestroy(user.beta);CHKERRQ(ierr);
ierr = MatDestroy(J); CHKERRQ(ierr);
ierr = SNESDestroy(snes);CHKERRQ(ierr);
ierr = DADestroy(user.da);CHKERRQ(ierr);
ierr = DADestroy(user.scalarda);CHKERRQ(ierr);
ierr = PetscFinalize();CHKERRQ(ierr);
return 0;
}
