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 dof, PetscInt cell, PetscInt face, PetscInt fStart, PetscInt fEnd, 10 PetscReal *cellPhi, const PetscScalar *x, 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,dof,cell,childFace,fStart,fEnd,cellPhi,x,cellgeom,cg,cx,cgrad);CHKERRQ(ierr); 26 } 27 } 28 } else { 29 PetscScalar *ncx; 30 PetscFVCellGeom *ncg; 31 const PetscInt *fcells; 32 PetscInt ncell, d; 33 PetscReal v[3]; 34 35 ierr = DMPlexGetSupport(dm, face, &fcells);CHKERRQ(ierr); 36 ncell = cell == fcells[0] ? fcells[1] : fcells[0]; 37 ierr = DMPlexPointLocalRead(dm, ncell, x, &ncx);CHKERRQ(ierr); 38 ierr = DMPlexPointLocalRead(dmCell, ncell, cellgeom, &ncg);CHKERRQ(ierr); 39 DMPlex_WaxpyD_Internal(dim, -1, cg->centroid, ncg->centroid, v); 40 for (d = 0; d < dof; ++d) { 41 /* We use the symmetric slope limited form of Berger, Aftosmis, and Murman 2005 */ 42 PetscReal phi, flim = 0.5 * PetscRealPart(ncx[d] - cx[d]) / DMPlex_DotD_Internal(dim, &cgrad[d*dim], v); 43 44 ierr = PetscLimiterLimit(lim, flim, &phi);CHKERRQ(ierr); 45 cellPhi[d] = PetscMin(cellPhi[d], phi); 46 } 47 } 48 PetscFunctionReturn(0); 49 } 50 51 #undef __FUNCT__ 52 #define __FUNCT__ "DMPlexReconstructGradients_Internal" 53 PetscErrorCode DMPlexReconstructGradients_Internal(DM dm, PetscFV fvm, PetscInt fStart, PetscInt fEnd, Vec faceGeometry, Vec cellGeometry, Vec locX, Vec grad) 54 { 55 DM dmFace, dmCell, dmGrad; 56 DMLabel ghostLabel; 57 PetscDS prob; 58 PetscLimiter lim; 59 const PetscScalar *facegeom, *cellgeom, *x; 60 PetscScalar *gr; 61 PetscReal *cellPhi; 62 PetscInt dim, face, cell, field, dof, cStart, cEnd, cEndInterior, nFields; 63 PetscErrorCode ierr; 64 65 PetscFunctionBegin; 66 ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr); 67 ierr = DMGetDS(dm, &prob);CHKERRQ(ierr); 68 ierr = PetscDSGetNumFields(prob, &nFields);CHKERRQ(ierr); 69 ierr = PetscDSGetFieldIndex(prob, (PetscObject) fvm, &field);CHKERRQ(ierr); 70 ierr = PetscDSGetFieldSize(prob, field, &dof);CHKERRQ(ierr); 71 ierr = DMGetLabel(dm, "ghost", &ghostLabel);CHKERRQ(ierr); 72 ierr = PetscFVGetLimiter(fvm, &lim);CHKERRQ(ierr); 73 ierr = VecGetDM(faceGeometry, &dmFace);CHKERRQ(ierr); 74 ierr = VecGetArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr); 75 ierr = VecGetDM(cellGeometry, &dmCell);CHKERRQ(ierr); 76 ierr = VecGetArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr); 77 ierr = VecGetArrayRead(locX, &x);CHKERRQ(ierr); 78 ierr = VecGetDM(grad, &dmGrad);CHKERRQ(ierr); 79 ierr = VecZeroEntries(grad);CHKERRQ(ierr); 80 ierr = VecGetArray(grad, &gr);CHKERRQ(ierr); 81 /* Reconstruct gradients */ 82 for (face = fStart; face < fEnd; ++face) { 83 const PetscInt *cells; 84 PetscFVFaceGeom *fg; 85 PetscScalar *cx[2]; 86 PetscScalar *cgrad[2]; 87 PetscBool boundary; 88 PetscInt ghost, c, pd, d, numChildren, numCells; 89 90 ierr = DMLabelGetValue(ghostLabel, face, &ghost);CHKERRQ(ierr); 91 ierr = DMIsBoundaryPoint(dm, face, &boundary);CHKERRQ(ierr); 92 ierr = DMPlexGetTreeChildren(dm, face, &numChildren, NULL);CHKERRQ(ierr); 93 if (ghost >= 0 || boundary || numChildren) continue; 94 ierr = DMPlexGetSupportSize(dm, face, &numCells);CHKERRQ(ierr); 95 if (numCells != 2) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_PLIB, "facet %d has %d support points: expected 2",face,numCells); 96 ierr = DMPlexGetSupport(dm, face, &cells);CHKERRQ(ierr); 97 ierr = DMPlexPointLocalRead(dmFace, face, facegeom, &fg);CHKERRQ(ierr); 98 for (c = 0; c < 2; ++c) { 99 if (nFields > 1) { 100 ierr = DMPlexPointLocalFieldRead(dm, cells[c], field, x, &cx[c]);CHKERRQ(ierr); 101 } else { 102 ierr = DMPlexPointLocalRead(dm, cells[c], x, &cx[c]);CHKERRQ(ierr); 103 } 104 ierr = DMPlexPointGlobalRef(dmGrad, cells[c], gr, &cgrad[c]);CHKERRQ(ierr); 105 } 106 for (pd = 0; pd < dof; ++pd) { 107 PetscScalar delta = cx[1][pd] - cx[0][pd]; 108 109 for (d = 0; d < dim; ++d) { 110 if (cgrad[0]) cgrad[0][pd*dim+d] += fg->grad[0][d] * delta; 111 if (cgrad[1]) cgrad[1][pd*dim+d] -= fg->grad[1][d] * delta; 112 } 113 } 114 } 115 /* Limit interior gradients (using cell-based loop because it generalizes better to vector limiters) */ 116 ierr = DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd);CHKERRQ(ierr); 117 ierr = DMPlexGetHybridBounds(dm, &cEndInterior, NULL, NULL, NULL);CHKERRQ(ierr); 118 cEndInterior = cEndInterior < 0 ? cEnd : cEndInterior; 119 ierr = DMGetWorkArray(dm, dof, PETSC_REAL, &cellPhi);CHKERRQ(ierr); 120 for (cell = dmGrad && lim ? cStart : cEnd; cell < cEndInterior; ++cell) { 121 const PetscInt *faces; 122 PetscScalar *cx; 123 PetscFVCellGeom *cg; 124 PetscScalar *cgrad; 125 PetscInt coneSize, f, pd, d; 126 127 ierr = DMPlexGetConeSize(dm, cell, &coneSize);CHKERRQ(ierr); 128 ierr = DMPlexGetCone(dm, cell, &faces);CHKERRQ(ierr); 129 ierr = DMPlexPointLocalRead(dm, cell, x, &cx);CHKERRQ(ierr); 130 ierr = DMPlexPointLocalRead(dmCell, cell, cellgeom, &cg);CHKERRQ(ierr); 131 ierr = DMPlexPointGlobalRef(dmGrad, cell, gr, &cgrad);CHKERRQ(ierr); 132 if (!cgrad) continue; /* Unowned overlap cell, we do not compute */ 133 /* Limiter will be minimum value over all neighbors */ 134 for (d = 0; d < dof; ++d) cellPhi[d] = PETSC_MAX_REAL; 135 for (f = 0; f < coneSize; ++f) { 136 ierr = DMPlexApplyLimiter_Internal(dm,dmCell,lim,dim,dof,cell,faces[f],fStart,fEnd,cellPhi,x,cellgeom,cg,cx,cgrad);CHKERRQ(ierr); 137 } 138 /* Apply limiter to gradient */ 139 for (pd = 0; pd < dof; ++pd) 140 /* Scalar limiter applied to each component separately */ 141 for (d = 0; d < dim; ++d) cgrad[pd*dim+d] *= cellPhi[pd]; 142 } 143 ierr = DMRestoreWorkArray(dm, dof, PETSC_REAL, &cellPhi);CHKERRQ(ierr); 144 ierr = VecRestoreArrayRead(faceGeometry, &facegeom);CHKERRQ(ierr); 145 ierr = VecRestoreArrayRead(cellGeometry, &cellgeom);CHKERRQ(ierr); 146 ierr = VecRestoreArrayRead(locX, &x);CHKERRQ(ierr); 147 ierr = VecRestoreArray(grad, &gr);CHKERRQ(ierr); 148 PetscFunctionReturn(0); 149 } 150 151 #undef __FUNCT__ 152 #define __FUNCT__ "DMPlexReconstructGradientsFVM" 153 /*@ 154 DMPlexReconstructGradientsFVM - reconstruct the gradient of a vector using a finite volume method. 155 156 Input Parameters: 157 + dm - the mesh 158 - locX - the local representation of the vector 159 160 Output Parameter: 161 . grad - the global representation of the gradient 162 163 Level: developer 164 165 .seealso: DMPlexSNESGetGradientDM() 166 @*/ 167 PetscErrorCode DMPlexReconstructGradientsFVM(DM dm, Vec locX, Vec grad) 168 { 169 PetscDS prob; 170 PetscInt Nf, f, fStart, fEnd; 171 PetscBool useFVM = PETSC_FALSE; 172 PetscFV fvm = NULL; 173 Vec faceGeometryFVM, cellGeometryFVM; 174 PetscFVCellGeom *cgeomFVM = NULL; 175 PetscFVFaceGeom *fgeomFVM = NULL; 176 DM dmGrad = NULL; 177 PetscErrorCode ierr; 178 179 PetscFunctionBegin; 180 ierr = DMGetDS(dm, &prob);CHKERRQ(ierr); 181 ierr = PetscDSGetNumFields(prob, &Nf);CHKERRQ(ierr); 182 for (f = 0; f < Nf; ++f) { 183 PetscObject obj; 184 PetscClassId id; 185 186 ierr = PetscDSGetDiscretization(prob, f, &obj);CHKERRQ(ierr); 187 ierr = PetscObjectGetClassId(obj, &id);CHKERRQ(ierr); 188 if (id == PETSCFV_CLASSID) {useFVM = PETSC_TRUE; fvm = (PetscFV) obj;} 189 } 190 if (!useFVM) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_SUP,"This dm does not have a finite volume discretization"); 191 ierr = DMPlexGetDataFVM(dm, fvm, &cellGeometryFVM, &faceGeometryFVM, &dmGrad);CHKERRQ(ierr); 192 if (!dmGrad) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_SUP,"This dm's finite volume discretization does not reconstruct gradients"); 193 ierr = VecGetArrayRead(faceGeometryFVM, (const PetscScalar **) &fgeomFVM);CHKERRQ(ierr); 194 ierr = VecGetArrayRead(cellGeometryFVM, (const PetscScalar **) &cgeomFVM);CHKERRQ(ierr); 195 ierr = DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd);CHKERRQ(ierr); 196 ierr = DMPlexReconstructGradients_Internal(dm, fvm, fStart, fEnd, faceGeometryFVM, cellGeometryFVM, locX, grad);CHKERRQ(ierr); 197 PetscFunctionReturn(0); 198 } 199 200