1 #include <petsc/private/dmpleximpl.h> /*I "petscdmplex.h" I*/ 2 #include <petscsf.h> 3 4 #include <petsc/private/petscfeimpl.h> 5 #include <petsc/private/petscfvimpl.h> 6 7 #undef __FUNCT__ 8 #define __FUNCT__ "DMPlexApplyLimiter_Internal" 9 static PetscErrorCode DMPlexApplyLimiter_Internal (DM dm, DM dmCell, PetscLimiter lim, PetscInt dim, PetscInt totDim, PetscInt cell, PetscInt face, PetscInt fStart, PetscInt fEnd, PetscReal *cellPhi, const PetscScalar *x, 10 const PetscScalar *cellgeom, const PetscFVCellGeom *cg, const PetscScalar *cx, const PetscScalar *cgrad) 11 { 12 const PetscInt *children; 13 PetscInt numChildren; 14 PetscErrorCode ierr; 15 16 PetscFunctionBegin; 17 ierr = DMPlexGetTreeChildren(dm,face,&numChildren,&children);CHKERRQ(ierr); 18 if (numChildren) { 19 PetscInt c; 20 21 for (c = 0; c < numChildren; c++) { 22 PetscInt childFace = children[c]; 23 24 if (childFace >= fStart && childFace < fEnd) { 25 ierr = DMPlexApplyLimiter_Internal(dm,dmCell,lim,dim,totDim,cell,childFace,fStart,fEnd,cellPhi,x,cellgeom,cg,cx,cgrad);CHKERRQ(ierr); 26 } 27 } 28 } 29 else { 30 PetscScalar *ncx; 31 PetscFVCellGeom *ncg; 32 const PetscInt *fcells; 33 PetscInt ncell, d; 34 PetscReal v[3]; 35 36 ierr = DMPlexGetSupport(dm, face, &fcells);CHKERRQ(ierr); 37 ncell = cell == fcells[0] ? fcells[1] : fcells[0]; 38 ierr = DMPlexPointLocalRead(dm, ncell, x, &ncx);CHKERRQ(ierr); 39 ierr = DMPlexPointLocalRead(dmCell, ncell, cellgeom, &ncg);CHKERRQ(ierr); 40 DMPlex_WaxpyD_Internal(dim, -1, cg->centroid, ncg->centroid, v); 41 for (d = 0; d < totDim; ++d) { 42 /* We use the symmetric slope limited form of Berger, Aftosmis, and Murman 2005 */ 43 PetscReal phi, flim = 0.5 * PetscRealPart(ncx[d] - cx[d]) / DMPlex_DotD_Internal(dim, &cgrad[d*dim], v); 44 45 ierr = PetscLimiterLimit(lim, flim, &phi);CHKERRQ(ierr); 46 cellPhi[d] = PetscMin(cellPhi[d], phi); 47 } 48 } 49 PetscFunctionReturn(0); 50 } 51 52 #undef __FUNCT__ 53 #define __FUNCT__ "DMPlexReconstructGradients_Internal" 54 PetscErrorCode DMPlexReconstructGradients_Internal(DM dm, PetscInt fStart, PetscInt fEnd, Vec faceGeometry, Vec cellGeometry, Vec locX, Vec grad) 55 { 56 DM dmFace, dmCell, dmGrad; 57 DMLabel ghostLabel; 58 PetscDS prob; 59 PetscFV fvm; 60 PetscLimiter lim; 61 const PetscScalar *facegeom, *cellgeom, *x; 62 PetscScalar *gr; 63 PetscReal *cellPhi; 64 PetscInt dim, face, cell, totDim, cStart, cEnd, cEndInterior; 65 PetscErrorCode ierr; 66 67 PetscFunctionBegin; 68 ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr); 69 ierr = DMGetDS(dm, &prob);CHKERRQ(ierr); 70 ierr = PetscDSGetTotalDimension(prob, &totDim);CHKERRQ(ierr); 71 ierr = DMGetLabel(dm, "ghost", &ghostLabel);CHKERRQ(ierr); 72 ierr = PetscDSGetDiscretization(prob, 0, (PetscObject *) &fvm);CHKERRQ(ierr); 73 ierr = PetscFVGetLimiter(fvm, &lim);CHKERRQ(ierr); 74 ierr = VecGetDM(faceGeometry, &dmFace);CHKERRQ(ierr); 75 ierr = VecGetArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr); 76 ierr = VecGetDM(cellGeometry, &dmCell);CHKERRQ(ierr); 77 ierr = VecGetArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr); 78 ierr = VecGetArrayRead(locX, &x);CHKERRQ(ierr); 79 ierr = VecGetDM(grad, &dmGrad);CHKERRQ(ierr); 80 ierr = VecZeroEntries(grad);CHKERRQ(ierr); 81 ierr = VecGetArray(grad, &gr);CHKERRQ(ierr); 82 /* Reconstruct gradients */ 83 for (face = fStart; face < fEnd; ++face) { 84 const PetscInt *cells; 85 PetscFVFaceGeom *fg; 86 PetscScalar *cx[2]; 87 PetscScalar *cgrad[2]; 88 PetscBool boundary; 89 PetscInt ghost, c, pd, d, numChildren, numCells; 90 91 ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr); 92 ierr = DMIsBoundaryPoint(dm, face, &boundary);CHKERRQ(ierr); 93 ierr = DMPlexGetTreeChildren(dm, face, &numChildren, NULL);CHKERRQ(ierr); 94 if (ghost >= 0 || boundary || numChildren) continue; 95 ierr = DMPlexGetSupportSize(dm, face, &numCells);CHKERRQ(ierr); 96 if (numCells != 2) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "facet %d has %d support points: expected 2",face,numCells); 97 ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr); 98 ierr = DMPlexPointLocalRead(dmFace, face, facegeom, &fg);CHKERRQ(ierr); 99 for (c = 0; c < 2; ++c) { 100 ierr = DMPlexPointLocalRead(dm, cells[c], x, &cx[c]);CHKERRQ(ierr); 101 ierr = DMPlexPointGlobalRef(dmGrad, cells[c], gr, &cgrad[c]);CHKERRQ(ierr); 102 } 103 for (pd = 0; pd < totDim; ++pd) { 104 PetscScalar delta = cx[1][pd] - cx[0][pd]; 105 106 for (d = 0; d < dim; ++d) { 107 if (cgrad[0]) cgrad[0][pd*dim+d] += fg->grad[0][d] * delta; 108 if (cgrad[1]) cgrad[1][pd*dim+d] -= fg->grad[1][d] * delta; 109 } 110 } 111 } 112 /* Limit interior gradients (using cell-based loop because it generalizes better to vector limiters) */ 113 ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr); 114 ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr); 115 cEndInterior = cEndInterior < 0 ? cEnd : cEndInterior; 116 ierr = DMGetWorkArray(dm, totDim, PETSC_REAL, &cellPhi);CHKERRQ(ierr); 117 for (cell = dmGrad && lim ? cStart : cEnd; cell < cEndInterior; ++cell) { 118 const PetscInt *faces; 119 PetscScalar *cx; 120 PetscFVCellGeom *cg; 121 PetscScalar *cgrad; 122 PetscInt coneSize, f, pd, d; 123 124 ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr); 125 ierr = DMPlexGetCone(dm, cell, &faces);CHKERRQ(ierr); 126 ierr = DMPlexPointLocalRead(dm, cell, x, &cx);CHKERRQ(ierr); 127 ierr = DMPlexPointLocalRead(dmCell, cell, cellgeom, &cg);CHKERRQ(ierr); 128 ierr = DMPlexPointGlobalRef(dmGrad, cell, gr, &cgrad);CHKERRQ(ierr); 129 if (!cgrad) continue; /* Unowned overlap cell, we do not compute */ 130 /* Limiter will be minimum value over all neighbors */ 131 for (d = 0; d < totDim; ++d) cellPhi[d] = PETSC_MAX_REAL; 132 for (f = 0; f < coneSize; ++f) { 133 ierr = DMPlexApplyLimiter_Internal(dm,dmCell,lim,dim,totDim,cell,faces[f],fStart,fEnd,cellPhi,x,cellgeom,cg,cx,cgrad);CHKERRQ(ierr); 134 } 135 /* Apply limiter to gradient */ 136 for (pd = 0; pd < totDim; ++pd) 137 /* Scalar limiter applied to each component separately */ 138 for (d = 0; d < dim; ++d) cgrad[pd*dim+d] *= cellPhi[pd]; 139 } 140 ierr = DMRestoreWorkArray(dm, totDim, PETSC_REAL, &cellPhi);CHKERRQ(ierr); 141 ierr = VecRestoreArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr); 142 ierr = VecRestoreArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr); 143 ierr = VecRestoreArrayRead(locX, &x);CHKERRQ(ierr); 144 ierr = VecRestoreArray(grad, &gr);CHKERRQ(ierr); 145 PetscFunctionReturn(0); 146 } 147 148 #undef __FUNCT__ 149 #define __FUNCT__ "DMPlexReconstructGradientsFVM" 150 /*@ 151 DMPlexReconstructGradientsFVM - reconstruct the gradient of a vector using a finite volume method. 152 153 Input Parameters: 154 + dm - the mesh 155 - locX - the local representation of the vector 156 157 Output Parameter: 158 . grad - the global representation of the gradient 159 160 Level: developer 161 162 .seealso: DMPlexSNESGetGradientDM() 163 @*/ 164 PetscErrorCode DMPlexReconstructGradientsFVM(DM dm, Vec locX, Vec grad) 165 { 166 PetscDS prob; 167 PetscInt Nf, f, fStart, fEnd; 168 PetscBool useFVM = PETSC_FALSE; 169 PetscFV fvm = NULL; 170 Vec faceGeometryFVM, cellGeometryFVM; 171 PetscFVCellGeom *cgeomFVM = NULL; 172 PetscFVFaceGeom *fgeomFVM = NULL; 173 DM dmGrad = NULL; 174 PetscErrorCode ierr; 175 176 PetscFunctionBegin; 177 ierr = DMGetDS(dm, &prob);CHKERRQ(ierr); 178 ierr = PetscDSGetNumFields(prob, &Nf);CHKERRQ(ierr); 179 for (f = 0; f < Nf; ++f) { 180 PetscObject obj; 181 PetscClassId id; 182 183 ierr = PetscDSGetDiscretization(prob, f, &obj);CHKERRQ(ierr); 184 ierr = PetscObjectGetClassId(obj, &id);CHKERRQ(ierr); 185 if (id == PETSCFV_CLASSID) {useFVM = PETSC_TRUE; fvm = (PetscFV) obj;} 186 } 187 if (!useFVM) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_SUP,"This dm does not have a finite volume discretization"); 188 ierr = DMPlexGetDataFVM(dm, fvm, &cellGeometryFVM, &faceGeometryFVM, &dmGrad);CHKERRQ(ierr); 189 if (!dmGrad) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_SUP,"This dm's finite volume discretization does not reconstruct gradients"); 190 ierr = VecGetArrayRead(faceGeometryFVM, (const PetscScalar **) &fgeomFVM);CHKERRQ(ierr); 191 ierr = VecGetArrayRead(cellGeometryFVM, (const PetscScalar **) &cgeomFVM);CHKERRQ(ierr); 192 ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr); 193 ierr = DMPlexReconstructGradients_Internal(dm, fStart, fEnd, faceGeometryFVM, cellGeometryFVM, locX, grad);CHKERRQ(ierr); 194 PetscFunctionReturn(0); 195 } 196 197