PetscErrorCode DMDAComputeCellGeometryFEM(DM dm, PetscInt cell, PetscQuadrature quad, PetscReal v0[], PetscReal J[], PetscReal invJ[], PetscReal detJ[])
{
DM cdm;
Vec coordinates;
const PetscReal *quadPoints;
PetscScalar *vertices = NULL;
PetscInt numQuadPoints, csize, dim, d, q;
PetscErrorCode ierr;
PetscFunctionBegin;
PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
ierr = DMDAGetInfo(dm, &dim, 0,0,0,0,0,0,0,0,0,0,0,0);CHKERRQ(ierr);
ierr = DMGetCoordinatesLocal(dm, &coordinates);CHKERRQ(ierr);
ierr = DMGetCoordinateDM(dm, &cdm);CHKERRQ(ierr);
ierr = DMDAVecGetClosure(cdm, NULL, coordinates, cell, &csize, &vertices);CHKERRQ(ierr);
for (d = 0; d < dim; ++d) v0[d] = PetscRealPart(vertices[d]);
switch (dim) {
case 2:
ierr = PetscQuadratureGetData(quad, NULL, &numQuadPoints, &quadPoints, NULL);CHKERRQ(ierr);
for (q = 0; q < numQuadPoints; ++q) {
ierr = DMDAComputeCellGeometry_2D(dm, vertices, &quadPoints[q*dim], J, invJ, detJ);CHKERRQ(ierr);
}
break;
default:
SETERRQ1(PetscObjectComm((PetscObject) dm), PETSC_ERR_SUP, "Dimension %d not supported", dim);
}
ierr = DMDAVecRestoreClosure(cdm, NULL, coordinates, cell, &csize, &vertices);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
/*
FormFunctionLocal - Form the local residual F from the local input X
Input Parameters:
+ dm - The mesh
. X - Local input vector
- user - The user context
Output Parameter:
. F - Local output vector
Note:
We form the residual one batch of elements at a time. This allows us to offload work onto an accelerator,
like a GPU, or vectorize on a multicore machine.
.seealso: FormJacobianLocal()
*/
PetscErrorCode FormFunctionLocal(DM dm, Vec X, Vec F, AppCtx *user)
{
const PetscInt debug = user->debug;
const PetscInt dim = user->dim;
PetscReal *coords, *v0, *J, *invJ, *detJ;
PetscScalar *elemVec, *u;
const PetscInt numCells = cEnd - cStart;
PetscInt cellDof = 0;
PetscInt maxQuad = 0;
PetscInt jacSize = 1;
PetscInt cStart, cEnd, c, field;
PetscErrorCode ierr;
PetscFunctionBegin;
ierr = PetscLogEventBegin(user->residualEvent,0,0,0,0);CHKERRQ(ierr);
ierr = VecSet(F, 0.0);CHKERRQ(ierr);
ierr = DMDAGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr);
for(field = 0; field < numFields; ++field) {
PetscInt dof = 1;
for(d = 0; d < dim; ++d) {dof *= user->q[field].numBasisFuncs*user->q[field].numComponents;}
cellDof += dof;
maxQuad = PetscMax(maxQuad, user->q[field].numQuadPoints);
}
for(d = 0; d < dim; ++d) {jacSize *= maxQuad;}
ierr = PetscMalloc3(dim,PetscReal,&coords,dim,PetscReal,&v0,jacSize,PetscReal,&J);CHKERRQ(ierr);
ierr = PetscMalloc4(numCells*cellDof,PetscScalar,&u,numCells*jacSize,PetscReal,&invJ,numCells,PetscReal,&detJ,numCells*cellDof,PetscScalar,&elemVec);CHKERRQ(ierr);
for(c = cStart; c < cEnd; ++c) {
const PetscScalar *x;
PetscInt i;
ierr = DMDAComputeCellGeometry(dm, c, v0, J, &invJ[c*jacSize], &detJ[c]);CHKERRQ(ierr);
if (detJ[c] <= 0.0) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Invalid determinant %g for element %d", detJ[c], c);
ierr = DMDAVecGetClosure(dm, PETSC_NULL, X, c, &x);CHKERRQ(ierr);
for(i = 0; i < cellDof; ++i) {
u[c*cellDof+i] = x[i];
}
}
for(field = 0; field < numFields; ++field) {
const PetscInt numQuadPoints = user->q[field].numQuadPoints;
const PetscInt numBasisFuncs = user->q[field].numBasisFuncs;
void (*f0)(PetscScalar u[], const PetscScalar gradU[], PetscScalar f0[]) = user->f0Funcs[field];
void (*f1)(PetscScalar u[], const PetscScalar gradU[], PetscScalar f1[]) = user->f1Funcs[field];
/* Conforming batches */
PetscInt blockSize = numBasisFuncs*numQuadPoints;
PetscInt numBlocks = 1;
PetscInt batchSize = numBlocks * blockSize;
PetscInt numBatches = user->numBatches;
PetscInt numChunks = numCells / (numBatches*batchSize);
ierr = IntegrateResidualBatchCPU(numChunks*numBatches*batchSize, numFields, field, u, invJ, detJ, user->q, f0, f1, elemVec, user);CHKERRQ(ierr);
/* Remainder */
PetscInt numRemainder = numCells % (numBatches * batchSize);
PetscInt offset = numCells - numRemainder;
ierr = IntegrateResidualBatchCPU(numRemainder, numFields, field, &u[offset*cellDof], &invJ[offset*dim*dim], &detJ[offset],
user->q, f0, f1, &elemVec[offset*cellDof], user);CHKERRQ(ierr);
}
for(c = cStart; c < cEnd; ++c) {
if (debug) {ierr = DMPrintCellVector(c, "Residual", cellDof, &elemVec[c*cellDof]);CHKERRQ(ierr);}
ierr = DMComplexVecSetClosure(dm, PETSC_NULL, F, c, &elemVec[c*cellDof], ADD_VALUES);CHKERRQ(ierr);
}
ierr = PetscFree4(u,invJ,detJ,elemVec);CHKERRQ(ierr);
ierr = PetscFree3(coords,v0,J);CHKERRQ(ierr);
if (user->showResidual) {
PetscInt p;
ierr = PetscPrintf(PETSC_COMM_WORLD, "Residual:\n");CHKERRQ(ierr);
for(p = 0; p < user->numProcs; ++p) {
if (p == user->rank) {
Vec f;
ierr = VecDuplicate(F, &f);CHKERRQ(ierr);
ierr = VecCopy(F, f);CHKERRQ(ierr);
ierr = VecChop(f, 1.0e-10);CHKERRQ(ierr);
ierr = VecView(f, PETSC_VIEWER_STDOUT_SELF);CHKERRQ(ierr);
ierr = VecDestroy(&f);CHKERRQ(ierr);
}
ierr = PetscBarrier((PetscObject) dm);CHKERRQ(ierr);
}
}
ierr = PetscLogEventEnd(user->residualEvent,0,0,0,0);CHKERRQ(ierr);
PetscFunctionReturn(0);
}
