1 static char help[] = "DMSwarm-PIC demonstrator of advecting points within cell DM defined by a DA or PLEX object \n\ 2 Options: \n\ 3 -ppcell : Number of times to sub-divide the reference cell when layout the initial particle coordinates \n\ 4 -meshtype : 0 ==> DA , 1 ==> PLEX \n\ 5 -nt : Number of timestep to perform \n\ 6 -view : Write out initial condition and time dependent data \n"; 7 8 #include <petsc.h> 9 #include <petscdm.h> 10 #include <petscdmda.h> 11 #include <petscdmswarm.h> 12 13 PetscErrorCode pic_advect(PetscInt ppcell, PetscInt meshtype) 14 { 15 const PetscInt dim = 2; 16 DM celldm, swarm; 17 PetscInt tk, nt = 200; 18 PetscBool view = PETSC_FALSE; 19 Vec pfields[1]; 20 PetscReal minradius; 21 PetscReal dt; 22 PetscReal vel[] = {1.0, 0.16}; 23 const char *fieldnames[] = {"phi"}; 24 PetscViewer viewer; 25 26 PetscFunctionBegin; 27 PetscCall(PetscOptionsGetBool(NULL, NULL, "-view", &view, NULL)); 28 PetscCall(PetscOptionsGetInt(NULL, NULL, "-nt", &nt, NULL)); 29 30 /* Create the background cell DM */ 31 if (meshtype == 0) { /* DA */ 32 PetscInt nxy; 33 PetscInt dof = 1; 34 PetscInt stencil_width = 1; 35 36 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Mesh type: DMDA\n")); 37 nxy = 33; 38 PetscCall(DMDACreate2d(PETSC_COMM_WORLD, DM_BOUNDARY_NONE, DM_BOUNDARY_NONE, DMDA_STENCIL_BOX, nxy, nxy, PETSC_DECIDE, PETSC_DECIDE, dof, stencil_width, NULL, NULL, &celldm)); 39 40 PetscCall(DMDASetElementType(celldm, DMDA_ELEMENT_Q1)); 41 42 PetscCall(DMSetFromOptions(celldm)); 43 44 PetscCall(DMSetUp(celldm)); 45 46 PetscCall(DMDASetUniformCoordinates(celldm, 0.0, 1.0, 0.0, 1.0, 0.0, 1.5)); 47 48 minradius = 1.0 / ((PetscReal)(nxy - 1)); 49 50 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "DA(minradius) %1.4e\n", (double)minradius)); 51 } 52 53 if (meshtype == 1) { /* PLEX */ 54 DM distributedMesh = NULL; 55 PetscInt numComp[] = {1}; 56 PetscInt numDof[] = {1, 0, 0}; /* vert, edge, cell */ 57 PetscInt faces[] = {1, 1, 1}; 58 PetscInt numBC = 0; 59 PetscSection section; 60 Vec cellgeom = NULL; 61 Vec facegeom = NULL; 62 63 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "Mesh type: DMPLEX\n")); 64 PetscCall(DMPlexCreateBoxMesh(PETSC_COMM_WORLD, dim, PETSC_TRUE, faces, NULL, NULL, PETSC_TRUE, &celldm)); 65 66 /* Distribute mesh over processes */ 67 PetscCall(DMPlexDistribute(celldm, 0, NULL, &distributedMesh)); 68 if (distributedMesh) { 69 PetscCall(DMDestroy(&celldm)); 70 celldm = distributedMesh; 71 } 72 73 PetscCall(DMSetFromOptions(celldm)); 74 75 PetscCall(DMPlexCreateSection(celldm, NULL, numComp, numDof, numBC, NULL, NULL, NULL, NULL, §ion)); 76 PetscCall(DMSetLocalSection(celldm, section)); 77 78 PetscCall(DMSetUp(celldm)); 79 80 /* Calling DMPlexComputeGeometryFVM() generates the value returned by DMPlexGetMinRadius() */ 81 PetscCall(DMPlexComputeGeometryFVM(celldm, &cellgeom, &facegeom)); 82 PetscCall(DMPlexGetMinRadius(celldm, &minradius)); 83 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "PLEX(minradius) %1.4e\n", (double)minradius)); 84 PetscCall(VecDestroy(&cellgeom)); 85 PetscCall(VecDestroy(&facegeom)); 86 PetscCall(PetscSectionDestroy(§ion)); 87 } 88 89 /* Create the DMSwarm */ 90 PetscCall(DMCreate(PETSC_COMM_WORLD, &swarm)); 91 PetscCall(DMSetType(swarm, DMSWARM)); 92 PetscCall(DMSetDimension(swarm, dim)); 93 94 /* Configure swarm to be of type PIC */ 95 PetscCall(DMSwarmSetType(swarm, DMSWARM_PIC)); 96 PetscCall(DMSwarmSetCellDM(swarm, celldm)); 97 98 /* Register two scalar fields within the DMSwarm */ 99 PetscCall(DMSwarmRegisterPetscDatatypeField(swarm, "phi", 1, PETSC_REAL)); 100 PetscCall(DMSwarmRegisterPetscDatatypeField(swarm, "region", 1, PETSC_REAL)); 101 PetscCall(DMSwarmFinalizeFieldRegister(swarm)); 102 103 /* Set initial local sizes of the DMSwarm with a buffer length of zero */ 104 PetscCall(DMSwarmSetLocalSizes(swarm, 4, 0)); 105 106 /* Insert swarm coordinates cell-wise */ 107 /*PetscCall(DMSwarmInsertPointsUsingCellDM(swarm,DMSWARMPIC_LAYOUT_REGULAR,ppcell));*/ 108 PetscCall(DMSwarmInsertPointsUsingCellDM(swarm, DMSWARMPIC_LAYOUT_SUBDIVISION, ppcell)); 109 110 /* Define initial conditions for th swarm fields "phi" and "region" */ 111 { 112 PetscReal *s_coor, *s_phi, *s_region; 113 PetscInt npoints, p; 114 115 PetscCall(DMSwarmGetLocalSize(swarm, &npoints)); 116 PetscCall(DMSwarmGetField(swarm, DMSwarmPICField_coor, NULL, NULL, (void **)&s_coor)); 117 PetscCall(DMSwarmGetField(swarm, "phi", NULL, NULL, (void **)&s_phi)); 118 PetscCall(DMSwarmGetField(swarm, "region", NULL, NULL, (void **)&s_region)); 119 for (p = 0; p < npoints; p++) { 120 PetscReal pos[2]; 121 pos[0] = s_coor[2 * p + 0]; 122 pos[1] = s_coor[2 * p + 1]; 123 124 s_region[p] = 1.0; 125 s_phi[p] = 1.0 + PetscExpReal(-200.0 * ((pos[0] - 0.5) * (pos[0] - 0.5) + (pos[1] - 0.5) * (pos[1] - 0.5))); 126 } 127 PetscCall(DMSwarmRestoreField(swarm, "region", NULL, NULL, (void **)&s_region)); 128 PetscCall(DMSwarmRestoreField(swarm, "phi", NULL, NULL, (void **)&s_phi)); 129 PetscCall(DMSwarmRestoreField(swarm, DMSwarmPICField_coor, NULL, NULL, (void **)&s_coor)); 130 } 131 132 /* Project initial value of phi onto the mesh */ 133 PetscCall(DMCreateGlobalVector(celldm, &pfields[0])); 134 PetscCall(DMSwarmProjectFields(swarm, NULL, 1, fieldnames, pfields, SCATTER_FORWARD)); 135 136 if (view) { 137 /* View swarm all swarm fields using data type PETSC_REAL */ 138 PetscCall(DMSwarmViewXDMF(swarm, "ic_dms.xmf")); 139 140 /* View projected swarm field "phi" */ 141 PetscCall(PetscViewerCreate(PETSC_COMM_WORLD, &viewer)); 142 PetscCall(PetscViewerSetType(viewer, PETSCVIEWERVTK)); 143 PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_WRITE)); 144 if (meshtype == 0) { /* DA */ 145 PetscCall(PetscViewerFileSetName(viewer, "ic_dmda.vts")); 146 PetscCall(VecView(pfields[0], viewer)); 147 } 148 if (meshtype == 1) { /* PLEX */ 149 PetscCall(PetscViewerFileSetName(viewer, "ic_dmplex.vtk")); 150 PetscCall(DMView(celldm, viewer)); 151 PetscCall(VecView(pfields[0], viewer)); 152 } 153 PetscCall(PetscViewerDestroy(&viewer)); 154 } 155 156 PetscCall(DMView(celldm, PETSC_VIEWER_STDOUT_WORLD)); 157 PetscCall(DMView(swarm, PETSC_VIEWER_STDOUT_WORLD)); 158 159 dt = 0.5 * minradius / PetscSqrtReal(vel[0] * vel[0] + vel[1] * vel[1]); 160 for (tk = 1; tk <= nt; tk++) { 161 PetscReal *s_coor; 162 PetscInt npoints, p; 163 164 PetscCall(PetscPrintf(PETSC_COMM_WORLD, "[step %" PetscInt_FMT "]\n", tk)); 165 /* advect with analytic prescribed (constant) velocity field */ 166 PetscCall(DMSwarmGetLocalSize(swarm, &npoints)); 167 PetscCall(DMSwarmGetField(swarm, DMSwarmPICField_coor, NULL, NULL, (void **)&s_coor)); 168 for (p = 0; p < npoints; p++) { 169 s_coor[2 * p + 0] += dt * vel[0]; 170 s_coor[2 * p + 1] += dt * vel[1]; 171 } 172 PetscCall(DMSwarmRestoreField(swarm, DMSwarmPICField_coor, NULL, NULL, (void **)&s_coor)); 173 174 PetscCall(DMSwarmMigrate(swarm, PETSC_TRUE)); 175 176 /* Ad-hoc cell filling algorithm */ 177 /* 178 The injection frequency is chosen for default DA case. 179 They will likely not be appropriate for the general case using an unstructure PLEX mesh. 180 */ 181 if (tk % 10 == 0) { 182 PetscReal dx = 1.0 / 32.0; 183 PetscInt npoints_dir_x[] = {32, 1}; 184 PetscReal min[2], max[2]; 185 186 min[0] = 0.5 * dx; 187 max[0] = 0.5 * dx + 31.0 * dx; 188 min[1] = 0.5 * dx; 189 max[1] = 0.5 * dx; 190 PetscCall(DMSwarmSetPointsUniformCoordinates(swarm, min, max, npoints_dir_x, ADD_VALUES)); 191 } 192 if (tk % 2 == 0) { 193 PetscReal dx = 1.0 / 32.0; 194 PetscInt npoints_dir_y[] = {2, 31}; 195 PetscReal min[2], max[2]; 196 197 min[0] = 0.05 * dx; 198 max[0] = 0.5 * dx; 199 min[1] = 0.5 * dx; 200 max[1] = 0.5 * dx + 31.0 * dx; 201 PetscCall(DMSwarmSetPointsUniformCoordinates(swarm, min, max, npoints_dir_y, ADD_VALUES)); 202 } 203 204 /* Project swarm field "phi" onto the cell DM */ 205 PetscCall(DMSwarmProjectFields(swarm, NULL, 1, fieldnames, pfields, SCATTER_FORWARD)); 206 207 if (view) { 208 PetscViewer viewer; 209 char fname[PETSC_MAX_PATH_LEN]; 210 211 /* View swarm fields */ 212 PetscCall(PetscSNPrintf(fname, PETSC_MAX_PATH_LEN - 1, "step%.4" PetscInt_FMT "_dms.xmf", tk)); 213 PetscCall(DMSwarmViewXDMF(swarm, fname)); 214 215 /* View projected field */ 216 PetscCall(PetscViewerCreate(PETSC_COMM_WORLD, &viewer)); 217 PetscCall(PetscViewerSetType(viewer, PETSCVIEWERVTK)); 218 PetscCall(PetscViewerFileSetMode(viewer, FILE_MODE_WRITE)); 219 220 if (meshtype == 0) { /* DA */ 221 PetscCall(PetscSNPrintf(fname, PETSC_MAX_PATH_LEN - 1, "step%.4" PetscInt_FMT "_dmda.vts", tk)); 222 PetscCall(PetscViewerFileSetName(viewer, fname)); 223 PetscCall(VecView(pfields[0], viewer)); 224 } 225 if (meshtype == 1) { /* PLEX */ 226 PetscCall(PetscSNPrintf(fname, PETSC_MAX_PATH_LEN - 1, "step%.4" PetscInt_FMT "_dmplex.vtk", tk)); 227 PetscCall(PetscViewerFileSetName(viewer, fname)); 228 PetscCall(DMView(celldm, viewer)); 229 PetscCall(VecView(pfields[0], viewer)); 230 } 231 PetscCall(PetscViewerDestroy(&viewer)); 232 } 233 } 234 PetscCall(VecDestroy(&pfields[0])); 235 PetscCall(DMDestroy(&celldm)); 236 PetscCall(DMDestroy(&swarm)); 237 PetscFunctionReturn(PETSC_SUCCESS); 238 } 239 240 int main(int argc, char **args) 241 { 242 PetscInt ppcell = 1; 243 PetscInt meshtype = 0; 244 245 PetscFunctionBeginUser; 246 PetscCall(PetscInitialize(&argc, &args, (char *)0, help)); 247 PetscCall(PetscOptionsGetInt(NULL, NULL, "-ppcell", &ppcell, NULL)); 248 PetscCall(PetscOptionsGetInt(NULL, NULL, "-meshtype", &meshtype, NULL)); 249 PetscCheck(meshtype <= 1, PETSC_COMM_WORLD, PETSC_ERR_USER, "-meshtype <value> must be 0 or 1"); 250 251 PetscCall(pic_advect(ppcell, meshtype)); 252 253 PetscCall(PetscFinalize()); 254 return 0; 255 } 256