xref: /petsc/src/dm/dt/tests/ex13.c (revision eb23ec828dce5d2018966dde62ea131297bcf5f7)
1 const char help[] = "Tests PetscDTPTrimmedEvalJet()";
2 
3 #include <petscdt.h>
4 #include <petscblaslapack.h>
5 #include <petscmat.h>
6 
7 static PetscErrorCode constructTabulationAndMass(PetscInt dim, PetscInt deg, PetscInt form, PetscInt jetDegree, PetscInt npoints,
8                                                  const PetscReal *points, const PetscReal *weights,
9                                                  PetscInt *_Nb, PetscInt *_Nf, PetscInt *_Nk,
10                                                  PetscReal **B, PetscScalar **M)
11 {
12   PetscInt       Nf; // Number of form components
13   PetscInt       Nbpt; // number of trimmed polynomials
14   PetscInt       Nk; // jet size
15   PetscReal     *p_trimmed;
16 
17   PetscFunctionBegin;
18   CHKERRQ(PetscDTBinomialInt(dim, PetscAbsInt(form), &Nf));
19   CHKERRQ(PetscDTPTrimmedSize(dim, deg, form, &Nbpt));
20   CHKERRQ(PetscDTBinomialInt(dim + jetDegree, dim, &Nk));
21   CHKERRQ(PetscMalloc1(Nbpt * Nf * Nk * npoints, &p_trimmed));
22   CHKERRQ(PetscDTPTrimmedEvalJet(dim, npoints, points, deg, form, jetDegree, p_trimmed));
23 
24   // compute the direct mass matrix
25   PetscScalar *M_trimmed;
26   CHKERRQ(PetscCalloc1(Nbpt * Nbpt, &M_trimmed));
27   for (PetscInt i = 0; i < Nbpt; i++) {
28     for (PetscInt j = 0; j < Nbpt; j++) {
29       PetscReal v = 0.;
30 
31       for (PetscInt f = 0; f < Nf; f++) {
32         const PetscReal *p_i = &p_trimmed[(i * Nf + f) * Nk * npoints];
33         const PetscReal *p_j = &p_trimmed[(j * Nf + f) * Nk * npoints];
34 
35         for (PetscInt pt = 0; pt < npoints; pt++) {
36           v += p_i[pt] * p_j[pt] * weights[pt];
37         }
38       }
39       M_trimmed[i * Nbpt + j] += v;
40     }
41   }
42   *_Nb = Nbpt;
43   *_Nf = Nf;
44   *_Nk = Nk;
45   *B = p_trimmed;
46   *M = M_trimmed;
47   PetscFunctionReturn(0);
48 }
49 
50 static PetscErrorCode test(PetscInt dim, PetscInt deg, PetscInt form, PetscInt jetDegree, PetscBool cond)
51 {
52   PetscQuadrature  q;
53   PetscInt         npoints;
54   const PetscReal *points;
55   const PetscReal *weights;
56   PetscInt         Nf; // Number of form components
57   PetscInt         Nk; // jet size
58   PetscInt         Nbpt; // number of trimmed polynomials
59   PetscReal       *p_trimmed;
60   PetscScalar     *M_trimmed;
61   PetscReal       *p_scalar;
62   PetscInt         Nbp; // number of scalar polynomials
63   PetscScalar     *Mcopy;
64   PetscScalar     *M_moments;
65   PetscReal        frob_err = 0.;
66   Mat              mat_trimmed;
67   Mat              mat_moments_T;
68   Mat              AinvB;
69   PetscInt         Nbm1;
70   Mat              Mm1;
71   PetscReal       *p_trimmed_copy;
72   PetscReal       *M_moment_real;
73   PetscErrorCode   ierr;
74 
75   PetscFunctionBegin;
76   // Construct an appropriate quadrature
77   CHKERRQ(PetscDTStroudConicalQuadrature(dim, 1, deg + 2, -1., 1., &q));
78   CHKERRQ(PetscQuadratureGetData(q, NULL, NULL, &npoints, &points, &weights));
79 
80   CHKERRQ(constructTabulationAndMass(dim, deg, form, jetDegree, npoints, points, weights, &Nbpt, &Nf, &Nk, &p_trimmed, &M_trimmed));
81 
82   CHKERRQ(PetscDTBinomialInt(dim + deg, dim, &Nbp));
83   CHKERRQ(PetscMalloc1(Nbp * Nk * npoints, &p_scalar));
84   CHKERRQ(PetscDTPKDEvalJet(dim, npoints, points, deg, jetDegree, p_scalar));
85 
86   CHKERRQ(PetscMalloc1(Nbpt * Nbpt, &Mcopy));
87   // Print the condition numbers (useful for testing out different bases internally in PetscDTPTrimmedEvalJet())
88 #if !defined(PETSC_USE_COMPLEX)
89   if (cond) {
90     PetscReal *S;
91     PetscScalar *work;
92     PetscBLASInt n = Nbpt;
93     PetscBLASInt lwork = 5 * Nbpt;
94     PetscBLASInt lierr;
95 
96     CHKERRQ(PetscMalloc1(Nbpt, &S));
97     CHKERRQ(PetscMalloc1(5*Nbpt, &work));
98     CHKERRQ(PetscArraycpy(Mcopy, M_trimmed, Nbpt * Nbpt));
99 
100     PetscStackCallBLAS("LAPACKgesvd",LAPACKgesvd_("N","N",&n,&n,Mcopy,&n,S,NULL,&n,NULL,&n,work,&lwork,&lierr));
101     PetscReal cond = S[0] / S[Nbpt - 1];
102     ierr = PetscPrintf(PETSC_COMM_WORLD, "dimension %D, degree %D, form %D: condition number %g\n", dim, deg, form, (double) cond);
103     CHKERRQ(PetscFree(work));
104     CHKERRQ(PetscFree(S));
105   }
106 #endif
107 
108   // compute the moments with the orthonormal polynomials
109   CHKERRQ(PetscCalloc1(Nbpt * Nbp * Nf, &M_moments));
110   for (PetscInt i = 0; i < Nbp; i++) {
111     for (PetscInt j = 0; j < Nbpt; j++) {
112       for (PetscInt f = 0; f < Nf; f++) {
113         PetscReal        v = 0.;
114         const PetscReal *p_i = &p_scalar[i * Nk * npoints];
115         const PetscReal *p_j = &p_trimmed[(j * Nf + f) * Nk * npoints];
116 
117         for (PetscInt pt = 0; pt < npoints; pt++) {
118           v += p_i[pt] * p_j[pt] * weights[pt];
119         }
120         M_moments[(i * Nf + f) * Nbpt + j] += v;
121       }
122     }
123   }
124 
125   // subtract M_moments^T * M_moments from M_trimmed: because the trimmed polynomials should be contained in
126   // the full polynomials, the result should be zero
127   CHKERRQ(PetscArraycpy(Mcopy, M_trimmed, Nbpt * Nbpt));
128   {
129     PetscBLASInt m = Nbpt;
130     PetscBLASInt n = Nbpt;
131     PetscBLASInt k = Nbp * Nf;
132     PetscScalar mone = -1.;
133     PetscScalar one = 1.;
134 
135     PetscStackCallBLAS("BLASgemm",BLASgemm_("N","T",&m,&n,&k,&mone,M_moments,&m,M_moments,&m,&one,Mcopy,&m));
136   }
137 
138   frob_err = 0.;
139   for (PetscInt i = 0; i < Nbpt * Nbpt; i++) frob_err += PetscRealPart(Mcopy[i]) * PetscRealPart(Mcopy[i]);
140   frob_err = PetscSqrtReal(frob_err);
141 
142   if (frob_err > PETSC_SMALL) {
143     SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dimension %D, degree %D, form %D: trimmed projection error %g", dim, deg, form, (double) frob_err);
144   }
145 
146   // P trimmed is also supposed to contain the polynomials of one degree less: construction M_moment[0:sub,:] * M_trimmed^{-1} * M_moments[0:sub,:]^T should be the identity matrix
147   CHKERRQ(MatCreateSeqDense(PETSC_COMM_SELF, Nbpt, Nbpt, M_trimmed, &mat_trimmed));
148   CHKERRQ(PetscDTBinomialInt(dim + deg - 1, dim, &Nbm1));
149   CHKERRQ(MatCreateSeqDense(PETSC_COMM_SELF, Nbpt, Nbm1 * Nf, M_moments, &mat_moments_T));
150   CHKERRQ(MatDuplicate(mat_moments_T, MAT_DO_NOT_COPY_VALUES, &AinvB));
151   CHKERRQ(MatLUFactor(mat_trimmed, NULL, NULL, NULL));
152   CHKERRQ(MatMatSolve(mat_trimmed, mat_moments_T, AinvB));
153   CHKERRQ(MatTransposeMatMult(mat_moments_T, AinvB, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &Mm1));
154   CHKERRQ(MatShift(Mm1, -1.));
155   CHKERRQ(MatNorm(Mm1, NORM_FROBENIUS, &frob_err));
156   if (frob_err > PETSC_SMALL) {
157     SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dimension %D, degree %D, form %D: trimmed reverse projection error %g", dim, deg, form, (double) frob_err);
158   }
159   CHKERRQ(MatDestroy(&Mm1));
160   CHKERRQ(MatDestroy(&AinvB));
161   CHKERRQ(MatDestroy(&mat_moments_T));
162 
163   // The Koszul differential applied to P trimmed (Lambda k+1) should be contained in P trimmed (Lambda k)
164   if (PetscAbsInt(form) < dim) {
165     PetscInt     Nf1, Nbpt1, Nk1;
166     PetscReal   *p_trimmed1;
167     PetscScalar *M_trimmed1;
168     PetscInt   (*pattern)[3];
169     PetscReal   *p_koszul;
170     PetscScalar *M_koszul;
171     PetscScalar *M_k_moment;
172     Mat          mat_koszul;
173     Mat          mat_k_moment_T;
174     Mat          AinvB;
175     Mat          prod;
176 
177     ierr = constructTabulationAndMass(dim, deg, form < 0 ? form - 1 : form + 1, 0, npoints, points, weights, &Nbpt1, &Nf1, &Nk1,
178                                       &p_trimmed1, &M_trimmed1);CHKERRQ(ierr);
179 
180     CHKERRQ(PetscMalloc1(Nf1 * (PetscAbsInt(form) + 1), &pattern));
181     CHKERRQ(PetscDTAltVInteriorPattern(dim, PetscAbsInt(form) + 1, pattern));
182 
183     // apply the Koszul operator
184     CHKERRQ(PetscCalloc1(Nbpt1 * Nf * npoints, &p_koszul));
185     for (PetscInt b = 0; b < Nbpt1; b++) {
186       for (PetscInt a = 0; a < Nf1 * (PetscAbsInt(form) + 1); a++) {
187         PetscInt         i,j,k;
188         PetscReal        sign;
189         PetscReal       *p_i;
190         const PetscReal *p_j;
191 
192         i = pattern[a][0];
193         if (form < 0) {
194           i = Nf-1-i;
195         }
196         j = pattern[a][1];
197         if (form < 0) {
198           j = Nf1-1-j;
199         }
200         k = pattern[a][2] < 0 ? -(pattern[a][2] + 1) : pattern[a][2];
201         sign = pattern[a][2] < 0 ? -1 : 1;
202         if (form < 0 && (i & 1) ^ (j & 1)) {
203           sign = -sign;
204         }
205 
206         p_i = &p_koszul[(b * Nf + i) * npoints];
207         p_j = &p_trimmed1[(b * Nf1 + j) * npoints];
208         for (PetscInt pt = 0; pt < npoints; pt++) {
209           p_i[pt] += p_j[pt] * points[pt * dim + k] * sign;
210         }
211       }
212     }
213 
214     // mass matrix of the result
215     CHKERRQ(PetscMalloc1(Nbpt1 * Nbpt1, &M_koszul));
216     for (PetscInt i = 0; i < Nbpt1; i++) {
217       for (PetscInt j = 0; j < Nbpt1; j++) {
218         PetscReal val = 0.;
219 
220         for (PetscInt v = 0; v < Nf; v++) {
221           const PetscReal *p_i = &p_koszul[(i * Nf + v) * npoints];
222           const PetscReal *p_j = &p_koszul[(j * Nf + v) * npoints];
223 
224           for (PetscInt pt = 0; pt < npoints; pt++) {
225             val += p_i[pt] * p_j[pt] * weights[pt];
226           }
227         }
228         M_koszul[i * Nbpt1 + j] = val;
229       }
230     }
231 
232     // moment matrix between the result and P trimmed
233     CHKERRQ(PetscMalloc1(Nbpt * Nbpt1, &M_k_moment));
234     for (PetscInt i = 0; i < Nbpt1; i++) {
235       for (PetscInt j = 0; j < Nbpt; j++) {
236         PetscReal val = 0.;
237 
238         for (PetscInt v = 0; v < Nf; v++) {
239           const PetscReal *p_i = &p_koszul[(i * Nf + v) * npoints];
240           const PetscReal *p_j = &p_trimmed[(j * Nf + v) * Nk * npoints];
241 
242           for (PetscInt pt = 0; pt < npoints; pt++) {
243             val += p_i[pt] * p_j[pt] * weights[pt];
244           }
245         }
246         M_k_moment[i * Nbpt + j] = val;
247       }
248     }
249 
250     // M_k_moment M_trimmed^{-1} M_k_moment^T == M_koszul
251     CHKERRQ(MatCreateSeqDense(PETSC_COMM_SELF, Nbpt1, Nbpt1, M_koszul, &mat_koszul));
252     CHKERRQ(MatCreateSeqDense(PETSC_COMM_SELF, Nbpt, Nbpt1, M_k_moment, &mat_k_moment_T));
253     CHKERRQ(MatDuplicate(mat_k_moment_T, MAT_DO_NOT_COPY_VALUES, &AinvB));
254     CHKERRQ(MatMatSolve(mat_trimmed, mat_k_moment_T, AinvB));
255     CHKERRQ(MatTransposeMatMult(mat_k_moment_T, AinvB, MAT_INITIAL_MATRIX, PETSC_DEFAULT, &prod));
256     CHKERRQ(MatAXPY(prod, -1., mat_koszul, SAME_NONZERO_PATTERN));
257     CHKERRQ(MatNorm(prod, NORM_FROBENIUS, &frob_err));
258     if (frob_err > PETSC_SMALL) {
259       SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dimension %D, degree %D, forms (%D, %D): koszul projection error %g", dim, deg, form, form < 0 ? (form-1):(form+1), (double) frob_err);
260     }
261 
262     CHKERRQ(MatDestroy(&prod));
263     CHKERRQ(MatDestroy(&AinvB));
264     CHKERRQ(MatDestroy(&mat_k_moment_T));
265     CHKERRQ(MatDestroy(&mat_koszul));
266     CHKERRQ(PetscFree(M_k_moment));
267     CHKERRQ(PetscFree(M_koszul));
268     CHKERRQ(PetscFree(p_koszul));
269     CHKERRQ(PetscFree(pattern));
270     CHKERRQ(PetscFree(p_trimmed1));
271     CHKERRQ(PetscFree(M_trimmed1));
272   }
273 
274   // M_moments has shape [Nbp][Nf][Nbpt]
275   // p_scalar has shape [Nbp][Nk][npoints]
276   // contracting on [Nbp] should be the same shape as
277   // p_trimmed, which is [Nbpt][Nf][Nk][npoints]
278   CHKERRQ(PetscCalloc1(Nbpt * Nf * Nk * npoints, &p_trimmed_copy));
279   CHKERRQ(PetscMalloc1(Nbp * Nf * Nbpt, &M_moment_real));
280   for (PetscInt i = 0; i < Nbp * Nf * Nbpt; i++) {
281     M_moment_real[i] = PetscRealPart(M_moments[i]);
282   }
283   for (PetscInt f = 0; f < Nf; f++) {
284     PetscBLASInt m = Nk * npoints;
285     PetscBLASInt n = Nbpt;
286     PetscBLASInt k = Nbp;
287     PetscBLASInt lda = Nk * npoints;
288     PetscBLASInt ldb = Nf * Nbpt;
289     PetscBLASInt ldc = Nf * Nk * npoints;
290     PetscReal    alpha = 1.0;
291     PetscReal    beta = 1.0;
292 
293     PetscStackCallBLAS("BLASREALgemm",BLASREALgemm_("N","T",&m,&n,&k,&alpha,p_scalar,&lda,&M_moment_real[f * Nbpt],&ldb,&beta,&p_trimmed_copy[f * Nk * npoints],&ldc));
294   }
295   frob_err = 0.;
296   for (PetscInt i = 0; i < Nbpt * Nf * Nk * npoints; i++) {
297     frob_err += (p_trimmed_copy[i] - p_trimmed[i]) * (p_trimmed_copy[i] - p_trimmed[i]);
298   }
299   frob_err = PetscSqrtReal(frob_err);
300 
301   if (frob_err > PETSC_SMALL) {
302     SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_PLIB, "dimension %D, degree %D, form %D: jet error %g", dim, deg, form, (double) frob_err);
303   }
304 
305   CHKERRQ(PetscFree(M_moment_real));
306   CHKERRQ(PetscFree(p_trimmed_copy));
307   CHKERRQ(MatDestroy(&mat_trimmed));
308   CHKERRQ(PetscFree(Mcopy));
309   CHKERRQ(PetscFree(M_moments));
310   CHKERRQ(PetscFree(M_trimmed));
311   CHKERRQ(PetscFree(p_trimmed));
312   CHKERRQ(PetscFree(p_scalar));
313   CHKERRQ(PetscQuadratureDestroy(&q));
314   PetscFunctionReturn(0);
315 }
316 
317 int main(int argc, char **argv)
318 {
319   PetscInt  max_dim = 3;
320   PetscInt  max_deg = 4;
321   PetscInt  k = 3;
322   PetscBool cond = PETSC_FALSE;
323 
324   PetscErrorCode ierr = PetscInitialize(&argc, &argv, NULL, help); if (ierr) return ierr;
325   ierr = PetscOptionsBegin(PETSC_COMM_WORLD,"","Options for PetscDTPTrimmedEvalJet() tests","none");CHKERRQ(ierr);
326   CHKERRQ(PetscOptionsInt("-max_dim", "Maximum dimension of the simplex",__FILE__,max_dim,&max_dim,NULL));
327   CHKERRQ(PetscOptionsInt("-max_degree", "Maximum degree of the trimmed polynomial space",__FILE__,max_deg,&max_deg,NULL));
328   CHKERRQ(PetscOptionsInt("-max_jet", "The number of derivatives to test",__FILE__,k,&k,NULL));
329   CHKERRQ(PetscOptionsBool("-cond", "Compute the condition numbers of the mass matrices of the bases",__FILE__,cond,&cond,NULL));
330   ierr = PetscOptionsEnd();CHKERRQ(ierr);
331   for (PetscInt dim = 2; dim <= max_dim; dim++) {
332     for (PetscInt deg = 1; deg <= max_deg; deg++) {
333       for (PetscInt form = -dim+1; form <= dim; form++) {
334         CHKERRQ(test(dim, deg, form, PetscMax(1, k), cond));
335       }
336     }
337   }
338   ierr = PetscFinalize();
339   return ierr;
340 }
341 
342 /*TEST
343 
344   test:
345     requires: !single
346     args:
347 
348 TEST*/
349