xref: /petsc/src/dm/impls/plex/tests/ex42.c (revision 69f65dfb176f3d3e756fc44d2300fd6791726976)
1 static const char help[] = "Simple libCEED test to calculate surface area using 1^T M 1";
2 
3 /*
4   This is a recreation of libCeed Example 2: https://libceed.readthedocs.io/en/latest/examples/ceed/
5 */
6 
7 #include <petscdmceed.h>
8 #include <petscdmplexceed.h>
9 #include <petscfeceed.h>
10 #include <petscdmplex.h>
11 #include <petscds.h>
12 
13 typedef struct {
14   PetscReal         areaExact;
15   CeedQFunctionUser setupgeo, apply;
16   const char       *setupgeofname, *applyfname;
17 } AppCtx;
18 
19 typedef struct {
20   CeedQFunction qf_apply;
21   CeedOperator  op_apply;
22   CeedVector    qdata, uceed, vceed;
23 } CeedData;
24 
25 static PetscErrorCode CeedDataDestroy(CeedData *data)
26 {
27   PetscFunctionBeginUser;
28   PetscCall(CeedVectorDestroy(&data->qdata));
29   PetscCall(CeedVectorDestroy(&data->uceed));
30   PetscCall(CeedVectorDestroy(&data->vceed));
31   PetscCall(CeedQFunctionDestroy(&data->qf_apply));
32   PetscCall(CeedOperatorDestroy(&data->op_apply));
33   PetscFunctionReturn(PETSC_SUCCESS);
34 }
35 
36 CEED_QFUNCTION(Mass)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out)
37 {
38   const CeedScalar *u = in[0], *qdata = in[1];
39   CeedScalar       *v = out[0];
40 
41   CeedPragmaSIMD for (CeedInt i = 0; i < Q; ++i) v[i] = qdata[i] * u[i];
42 
43   return 0;
44 }
45 
46 /*
47 // Reference (parent) 2D coordinates: X \in [-1, 1]^2
48 //
49 // Global physical coordinates given by the mesh (3D): xx \in [-l, l]^3
50 //
51 // Local physical coordinates on the manifold (2D): x \in [-l, l]^2
52 //
53 // Change of coordinates matrix computed by the library:
54 //   (physical 3D coords relative to reference 2D coords)
55 //   dxx_j/dX_i (indicial notation) [3 * 2]
56 //
57 // Change of coordinates x (physical 2D) relative to xx (phyisical 3D):
58 //   dx_i/dxx_j (indicial notation) [2 * 3]
59 //
60 // Change of coordinates x (physical 2D) relative to X (reference 2D):
61 //   (by chain rule)
62 //   dx_i/dX_j = dx_i/dxx_k * dxx_k/dX_j
63 //
64 // The quadrature data is stored in the array qdata.
65 //
66 // We require the determinant of the Jacobian to properly compute integrals of the form: int(u v)
67 //
68 // Qdata: w * det(dx_i/dX_j)
69 */
70 CEED_QFUNCTION(SetupMassGeoCube)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out)
71 {
72   const CeedScalar *J = in[1], *w = in[2];
73   CeedScalar       *qdata = out[0];
74 
75   CeedPragmaSIMD for (CeedInt i = 0; i < Q; ++i)
76   {
77     // Read dxxdX Jacobian entries, stored as [[0 3], [1 4], [2 5]]
78     const CeedScalar dxxdX[3][2] = {
79       {J[i + Q * 0], J[i + Q * 3]},
80       {J[i + Q * 1], J[i + Q * 4]},
81       {J[i + Q * 2], J[i + Q * 5]}
82     };
83     // Modulus of dxxdX column vectors
84     const CeedScalar modg1 = PetscSqrtReal(dxxdX[0][0] * dxxdX[0][0] + dxxdX[1][0] * dxxdX[1][0] + dxxdX[2][0] * dxxdX[2][0]);
85     const CeedScalar modg2 = PetscSqrtReal(dxxdX[0][1] * dxxdX[0][1] + dxxdX[1][1] * dxxdX[1][1] + dxxdX[2][1] * dxxdX[2][1]);
86     // Use normalized column vectors of dxxdX as rows of dxdxx
87     const CeedScalar dxdxx[2][3] = {
88       {dxxdX[0][0] / modg1, dxxdX[1][0] / modg1, dxxdX[2][0] / modg1},
89       {dxxdX[0][1] / modg2, dxxdX[1][1] / modg2, dxxdX[2][1] / modg2}
90     };
91 
92     CeedScalar dxdX[2][2];
93     for (int j = 0; j < 2; ++j)
94       for (int k = 0; k < 2; ++k) {
95         dxdX[j][k] = 0;
96         for (int l = 0; l < 3; ++l) dxdX[j][k] += dxdxx[j][l] * dxxdX[l][k];
97       }
98     qdata[i + Q * 0] = (dxdX[0][0] * dxdX[1][1] - dxdX[1][0] * dxdX[0][1]) * w[i]; /* det J * weight */
99   }
100   return 0;
101 }
102 
103 /*
104 // Reference (parent) 2D coordinates: X \in [-1, 1]^2
105 //
106 // Global 3D physical coordinates given by the mesh: xx \in [-R, R]^3
107 //   with R radius of the sphere
108 //
109 // Local 3D physical coordinates on the 2D manifold: x \in [-l, l]^3
110 //   with l half edge of the cube inscribed in the sphere
111 //
112 // Change of coordinates matrix computed by the library:
113 //   (physical 3D coords relative to reference 2D coords)
114 //   dxx_j/dX_i (indicial notation) [3 * 2]
115 //
116 // Change of coordinates x (on the 2D manifold) relative to xx (phyisical 3D):
117 //   dx_i/dxx_j (indicial notation) [3 * 3]
118 //
119 // Change of coordinates x (on the 2D manifold) relative to X (reference 2D):
120 //   (by chain rule)
121 //   dx_i/dX_j = dx_i/dxx_k * dxx_k/dX_j [3 * 2]
122 //
123 // modJ is given by the magnitude of the cross product of the columns of dx_i/dX_j
124 //
125 // The quadrature data is stored in the array qdata.
126 //
127 // We require the determinant of the Jacobian to properly compute integrals of
128 //   the form: int(u v)
129 //
130 // Qdata: modJ * w
131 */
132 CEED_QFUNCTION(SetupMassGeoSphere)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out)
133 {
134   const CeedScalar *X = in[0], *J = in[1], *w = in[2];
135   CeedScalar       *qdata = out[0];
136 
137   CeedPragmaSIMD for (CeedInt i = 0; i < Q; ++i)
138   {
139     const CeedScalar xx[3][1] = {{X[i + 0 * Q]}, {X[i + 1 * Q]}, {X[i + 2 * Q]}};
140     // Read dxxdX Jacobian entries, stored as [[0 3], [1 4], [2 5]]
141     const CeedScalar dxxdX[3][2] = {
142       {J[i + Q * 0], J[i + Q * 3]},
143       {J[i + Q * 1], J[i + Q * 4]},
144       {J[i + Q * 2], J[i + Q * 5]}
145     };
146     // Setup
147     const CeedScalar modxxsq = xx[0][0] * xx[0][0] + xx[1][0] * xx[1][0] + xx[2][0] * xx[2][0];
148     CeedScalar       xxsq[3][3];
149     for (int j = 0; j < 3; ++j)
150       for (int k = 0; k < 3; ++k) {
151         xxsq[j][k] = 0.;
152         for (int l = 0; l < 1; ++l) xxsq[j][k] += xx[j][l] * xx[k][l] / (sqrt(modxxsq) * modxxsq);
153       }
154 
155     const CeedScalar dxdxx[3][3] = {
156       {1. / sqrt(modxxsq) - xxsq[0][0], -xxsq[0][1],                     -xxsq[0][2]                    },
157       {-xxsq[1][0],                     1. / sqrt(modxxsq) - xxsq[1][1], -xxsq[1][2]                    },
158       {-xxsq[2][0],                     -xxsq[2][1],                     1. / sqrt(modxxsq) - xxsq[2][2]}
159     };
160 
161     CeedScalar dxdX[3][2];
162     for (int j = 0; j < 3; ++j)
163       for (int k = 0; k < 2; ++k) {
164         dxdX[j][k] = 0.;
165         for (int l = 0; l < 3; ++l) dxdX[j][k] += dxdxx[j][l] * dxxdX[l][k];
166       }
167     // J is given by the cross product of the columns of dxdX
168     const CeedScalar J[3][1] = {{dxdX[1][0] * dxdX[2][1] - dxdX[2][0] * dxdX[1][1]}, {dxdX[2][0] * dxdX[0][1] - dxdX[0][0] * dxdX[2][1]}, {dxdX[0][0] * dxdX[1][1] - dxdX[1][0] * dxdX[0][1]}};
169     // Use the magnitude of J as our detJ (volume scaling factor)
170     const CeedScalar modJ = sqrt(J[0][0] * J[0][0] + J[1][0] * J[1][0] + J[2][0] * J[2][0]);
171     qdata[i + Q * 0]      = modJ * w[i];
172   }
173   return 0;
174 }
175 
176 static PetscErrorCode ProcessOptions(MPI_Comm comm, AppCtx *ctx)
177 {
178   DMPlexShape shape = DM_SHAPE_UNKNOWN;
179 
180   PetscFunctionBeginUser;
181   PetscOptionsBegin(comm, "", "libCEED Test Options", "DMPLEX");
182   PetscOptionsEnd();
183   PetscCall(PetscOptionsGetEnum(NULL, NULL, "-dm_plex_shape", DMPlexShapes, (PetscEnum *)&shape, NULL));
184   ctx->setupgeo      = NULL;
185   ctx->setupgeofname = NULL;
186   ctx->apply         = Mass;
187   ctx->applyfname    = Mass_loc;
188   ctx->areaExact     = 0.0;
189   switch (shape) {
190   case DM_SHAPE_BOX_SURFACE:
191     ctx->setupgeo      = SetupMassGeoCube;
192     ctx->setupgeofname = SetupMassGeoCube_loc;
193     ctx->areaExact     = 6.0;
194     break;
195   case DM_SHAPE_SPHERE:
196     ctx->setupgeo      = SetupMassGeoSphere;
197     ctx->setupgeofname = SetupMassGeoSphere_loc;
198     ctx->areaExact     = 4.0 * M_PI;
199     break;
200   default:
201     break;
202   }
203   PetscFunctionReturn(PETSC_SUCCESS);
204 }
205 
206 static PetscErrorCode CreateMesh(MPI_Comm comm, AppCtx *ctx, DM *dm)
207 {
208   PetscFunctionBegin;
209   PetscCall(DMCreate(comm, dm));
210   PetscCall(DMSetType(*dm, DMPLEX));
211   PetscCall(DMSetFromOptions(*dm));
212   PetscCall(DMViewFromOptions(*dm, NULL, "-dm_view"));
213 #ifdef PETSC_HAVE_LIBCEED
214   {
215     Ceed        ceed;
216     const char *usedresource;
217 
218     PetscCall(DMGetCeed(*dm, &ceed));
219     PetscCall(CeedGetResource(ceed, &usedresource));
220     PetscCall(PetscPrintf(PetscObjectComm((PetscObject)*dm), "libCEED Backend: %s\n", usedresource));
221   }
222 #endif
223   PetscFunctionReturn(PETSC_SUCCESS);
224 }
225 
226 static PetscErrorCode SetupDiscretization(DM dm)
227 {
228   DM        cdm;
229   PetscFE   fe, cfe;
230   PetscInt  dim, cnc;
231   PetscBool simplex;
232 
233   PetscFunctionBeginUser;
234   PetscCall(DMGetDimension(dm, &dim));
235   PetscCall(DMPlexIsSimplex(dm, &simplex));
236   PetscCall(PetscFECreateDefault(PETSC_COMM_SELF, dim, 1, simplex, NULL, PETSC_DETERMINE, &fe));
237   PetscCall(PetscFESetName(fe, "indicator"));
238   PetscCall(DMAddField(dm, NULL, (PetscObject)fe));
239   PetscCall(PetscFEDestroy(&fe));
240   PetscCall(DMCreateDS(dm));
241   PetscCall(DMPlexSetClosurePermutationTensor(dm, PETSC_DETERMINE, NULL));
242   PetscCall(DMGetCoordinateDim(dm, &cnc));
243   PetscCall(PetscFECreateDefault(PETSC_COMM_SELF, dim, cnc, simplex, NULL, PETSC_DETERMINE, &cfe));
244   PetscCall(DMProjectCoordinates(dm, cfe));
245   PetscCall(PetscFEDestroy(&cfe));
246   PetscCall(DMGetCoordinateDM(dm, &cdm));
247   PetscCall(DMPlexSetClosurePermutationTensor(cdm, PETSC_DETERMINE, NULL));
248   PetscFunctionReturn(PETSC_SUCCESS);
249 }
250 
251 static PetscErrorCode LibCeedSetupByDegree(DM dm, AppCtx *ctx, CeedData *data)
252 {
253   PetscDS             ds;
254   PetscFE             fe, cfe;
255   Ceed                ceed;
256   CeedElemRestriction Erestrictx, Erestrictu, Erestrictq;
257   CeedQFunction       qf_setupgeo;
258   CeedOperator        op_setupgeo;
259   CeedVector          xcoord;
260   CeedBasis           basisu, basisx;
261   CeedInt             Nqdata = 1;
262   CeedInt             nqpts, nqptsx;
263   DM                  cdm;
264   Vec                 coords;
265   const PetscScalar  *coordArray;
266   PetscInt            dim, cdim, cStart, cEnd, Ncell;
267 
268   PetscFunctionBeginUser;
269   PetscCall(DMGetCeed(dm, &ceed));
270   PetscCall(DMGetDimension(dm, &dim));
271   PetscCall(DMGetCoordinateDim(dm, &cdim));
272   PetscCall(DMPlexGetHeightStratum(dm, 0, &cStart, &cEnd));
273   Ncell = cEnd - cStart;
274   // CEED bases
275   PetscCall(DMGetDS(dm, &ds));
276   PetscCall(PetscDSGetDiscretization(ds, 0, (PetscObject *)&fe));
277   PetscCall(PetscFEGetCeedBasis(fe, &basisu));
278   PetscCall(DMGetCoordinateDM(dm, &cdm));
279   PetscCall(DMGetDS(cdm, &ds));
280   PetscCall(PetscDSGetDiscretization(ds, 0, (PetscObject *)&cfe));
281   PetscCall(PetscFEGetCeedBasis(cfe, &basisx));
282 
283   PetscCall(DMPlexGetCeedRestriction(cdm, NULL, 0, 0, 0, &Erestrictx));
284   PetscCall(DMPlexGetCeedRestriction(dm, NULL, 0, 0, 0, &Erestrictu));
285   PetscCall(CeedBasisGetNumQuadraturePoints(basisu, &nqpts));
286   PetscCall(CeedBasisGetNumQuadraturePoints(basisx, &nqptsx));
287   PetscCheck(nqptsx == nqpts, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Number of qpoints for u %" PetscInt_FMT " != %" PetscInt_FMT " Number of qpoints for x", nqpts, nqptsx);
288   PetscCall(CeedElemRestrictionCreateStrided(ceed, Ncell, nqpts, Nqdata, Nqdata * Ncell * nqpts, CEED_STRIDES_BACKEND, &Erestrictq));
289 
290   PetscCall(DMGetCoordinatesLocal(dm, &coords));
291   PetscCall(VecGetArrayRead(coords, &coordArray));
292   PetscCall(CeedElemRestrictionCreateVector(Erestrictx, &xcoord, NULL));
293   PetscCall(CeedVectorSetArray(xcoord, CEED_MEM_HOST, CEED_COPY_VALUES, (PetscScalar *)coordArray));
294   PetscCall(VecRestoreArrayRead(coords, &coordArray));
295 
296   // Create the vectors that will be needed in setup and apply
297   PetscCall(CeedElemRestrictionCreateVector(Erestrictu, &data->uceed, NULL));
298   PetscCall(CeedElemRestrictionCreateVector(Erestrictu, &data->vceed, NULL));
299   PetscCall(CeedElemRestrictionCreateVector(Erestrictq, &data->qdata, NULL));
300 
301   // Create the Q-function that builds the operator (i.e. computes its quadrature data) and set its context data
302   PetscCall(CeedQFunctionCreateInterior(ceed, 1, ctx->setupgeo, ctx->setupgeofname, &qf_setupgeo));
303   PetscCall(CeedQFunctionAddInput(qf_setupgeo, "x", cdim, CEED_EVAL_INTERP));
304   PetscCall(CeedQFunctionAddInput(qf_setupgeo, "dx", cdim * dim, CEED_EVAL_GRAD));
305   PetscCall(CeedQFunctionAddInput(qf_setupgeo, "weight", 1, CEED_EVAL_WEIGHT));
306   PetscCall(CeedQFunctionAddOutput(qf_setupgeo, "qdata", Nqdata, CEED_EVAL_NONE));
307 
308   // Set up the mass operator
309   PetscCall(CeedQFunctionCreateInterior(ceed, 1, ctx->apply, ctx->applyfname, &data->qf_apply));
310   PetscCall(CeedQFunctionAddInput(data->qf_apply, "u", 1, CEED_EVAL_INTERP));
311   PetscCall(CeedQFunctionAddInput(data->qf_apply, "qdata", Nqdata, CEED_EVAL_NONE));
312   PetscCall(CeedQFunctionAddOutput(data->qf_apply, "v", 1, CEED_EVAL_INTERP));
313 
314   // Create the operator that builds the quadrature data for the operator
315   PetscCall(CeedOperatorCreate(ceed, qf_setupgeo, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE, &op_setupgeo));
316   PetscCall(CeedOperatorSetField(op_setupgeo, "x", Erestrictx, basisx, CEED_VECTOR_ACTIVE));
317   PetscCall(CeedOperatorSetField(op_setupgeo, "dx", Erestrictx, basisx, CEED_VECTOR_ACTIVE));
318   PetscCall(CeedOperatorSetField(op_setupgeo, "weight", CEED_ELEMRESTRICTION_NONE, basisx, CEED_VECTOR_NONE));
319   PetscCall(CeedOperatorSetField(op_setupgeo, "qdata", Erestrictq, CEED_BASIS_COLLOCATED, CEED_VECTOR_ACTIVE));
320 
321   // Create the mass operator
322   PetscCall(CeedOperatorCreate(ceed, data->qf_apply, CEED_QFUNCTION_NONE, CEED_QFUNCTION_NONE, &data->op_apply));
323   PetscCall(CeedOperatorSetField(data->op_apply, "u", Erestrictu, basisu, CEED_VECTOR_ACTIVE));
324   PetscCall(CeedOperatorSetField(data->op_apply, "qdata", Erestrictq, CEED_BASIS_COLLOCATED, data->qdata));
325   PetscCall(CeedOperatorSetField(data->op_apply, "v", Erestrictu, basisu, CEED_VECTOR_ACTIVE));
326 
327   // Setup qdata
328   PetscCall(CeedOperatorApply(op_setupgeo, xcoord, data->qdata, CEED_REQUEST_IMMEDIATE));
329 
330   PetscCall(CeedElemRestrictionDestroy(&Erestrictq));
331   PetscCall(CeedQFunctionDestroy(&qf_setupgeo));
332   PetscCall(CeedOperatorDestroy(&op_setupgeo));
333   PetscCall(CeedVectorDestroy(&xcoord));
334   PetscFunctionReturn(PETSC_SUCCESS);
335 }
336 
337 int main(int argc, char **argv)
338 {
339   MPI_Comm     comm;
340   DM           dm;
341   AppCtx       ctx;
342   Vec          U, Uloc, V, Vloc;
343   PetscScalar *v;
344   PetscScalar  area;
345   CeedData     ceeddata;
346 
347   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
348   comm = PETSC_COMM_WORLD;
349   PetscCall(ProcessOptions(comm, &ctx));
350   PetscCall(CreateMesh(comm, &ctx, &dm));
351   PetscCall(SetupDiscretization(dm));
352 
353   PetscCall(LibCeedSetupByDegree(dm, &ctx, &ceeddata));
354 
355   PetscCall(DMCreateGlobalVector(dm, &U));
356   PetscCall(DMCreateLocalVector(dm, &Uloc));
357   PetscCall(VecDuplicate(U, &V));
358   PetscCall(VecDuplicate(Uloc, &Vloc));
359 
360   /**/
361   PetscCall(VecSet(Uloc, 1.));
362   PetscCall(VecZeroEntries(V));
363   PetscCall(VecZeroEntries(Vloc));
364   PetscCall(VecGetArray(Vloc, &v));
365   PetscCall(CeedVectorSetArray(ceeddata.vceed, CEED_MEM_HOST, CEED_USE_POINTER, v));
366   PetscCall(CeedVectorSetValue(ceeddata.uceed, 1.0));
367   PetscCall(CeedOperatorApply(ceeddata.op_apply, ceeddata.uceed, ceeddata.vceed, CEED_REQUEST_IMMEDIATE));
368   PetscCall(CeedVectorTakeArray(ceeddata.vceed, CEED_MEM_HOST, NULL));
369   PetscCall(VecRestoreArray(Vloc, &v));
370   PetscCall(DMLocalToGlobalBegin(dm, Vloc, ADD_VALUES, V));
371   PetscCall(DMLocalToGlobalEnd(dm, Vloc, ADD_VALUES, V));
372 
373   PetscCall(VecSum(V, &area));
374   if (ctx.areaExact > 0.) {
375     PetscReal error = PetscAbsReal(area - ctx.areaExact);
376     PetscReal tol   = PETSC_SMALL;
377 
378     PetscCall(PetscPrintf(comm, "Exact mesh surface area    : % .*f\n", PetscAbsReal(ctx.areaExact - round(ctx.areaExact)) > 1E-15 ? 14 : 1, (double)ctx.areaExact));
379     PetscCall(PetscPrintf(comm, "Computed mesh surface area : % .*f\n", PetscAbsScalar(area - round(area)) > 1E-15 ? 14 : 1, (double)PetscRealPart(area)));
380     if (error > tol) {
381       PetscCall(PetscPrintf(comm, "Area error                 : % .14g\n", (double)error));
382     } else {
383       PetscCall(PetscPrintf(comm, "Area verifies!\n"));
384     }
385   }
386 
387   PetscCall(CeedDataDestroy(&ceeddata));
388   PetscCall(VecDestroy(&U));
389   PetscCall(VecDestroy(&Uloc));
390   PetscCall(VecDestroy(&V));
391   PetscCall(VecDestroy(&Vloc));
392   PetscCall(DMDestroy(&dm));
393   return PetscFinalize();
394 }
395 
396 /*TEST
397 
398   build:
399     requires: libceed
400 
401   testset:
402     args: -dm_plex_simplex 0 -petscspace_degree 3 -dm_view -dm_petscds_view \
403           -petscfe_default_quadrature_order 4 -cdm_default_quadrature_order 4
404     filter: sed "s /cpu/self/xsmm /cpu/self/avx "
405 
406     test:
407       suffix: cube_3
408       args: -dm_plex_shape box_surface -dm_refine 2
409 
410     test:
411       suffix: cube_3_p4
412       nsize: 4
413       args: -petscpartitioner_type simple -dm_refine_pre 1 -dm_plex_shape box_surface -dm_refine 1
414 
415     test:
416       suffix: sphere_3
417       args: -dm_plex_shape sphere -dm_refine 3
418 
419     test:
420       suffix: sphere_3_p4
421       nsize: 4
422       args: -petscpartitioner_type simple -dm_refine_pre 1 -dm_plex_shape sphere -dm_refine 2
423 
424 TEST*/
425