xref: /libCEED/interface/ceed-basis.c (revision f5066b3615781dbcd74af2f846f96d7648d0187d)
1 // Copyright (c) 2017, Lawrence Livermore National Security, LLC. Produced at
2 // the Lawrence Livermore National Laboratory. LLNL-CODE-734707. All Rights
3 // reserved. See files LICENSE and NOTICE for details.
4 //
5 // This file is part of CEED, a collection of benchmarks, miniapps, software
6 // libraries and APIs for efficient high-order finite element and spectral
7 // element discretizations for exascale applications. For more information and
8 // source code availability see http://github.com/ceed.
9 //
10 // The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11 // a collaborative effort of two U.S. Department of Energy organizations (Office
12 // of Science and the National Nuclear Security Administration) responsible for
13 // the planning and preparation of a capable exascale ecosystem, including
14 // software, applications, hardware, advanced system engineering and early
15 // testbed platforms, in support of the nation's exascale computing imperative.
16 
17 #include <ceed/ceed.h>
18 #include <ceed/backend.h>
19 #include <ceed-impl.h>
20 #include <math.h>
21 #include <stdbool.h>
22 #include <stdio.h>
23 #include <string.h>
24 
25 /// @file
26 /// Implementation of CeedBasis interfaces
27 
28 /// @cond DOXYGEN_SKIP
29 static struct CeedBasis_private ceed_basis_collocated;
30 /// @endcond
31 
32 /// @addtogroup CeedBasisUser
33 /// @{
34 
35 /// Indicate that the quadrature points are collocated with the nodes
36 const CeedBasis CEED_BASIS_COLLOCATED = &ceed_basis_collocated;
37 
38 /// @}
39 
40 /// ----------------------------------------------------------------------------
41 /// CeedBasis Library Internal Functions
42 /// ----------------------------------------------------------------------------
43 /// @addtogroup CeedBasisDeveloper
44 /// @{
45 
46 /**
47   @brief Compute Householder reflection
48 
49     Computes A = (I - b v v^T) A
50     where A is an mxn matrix indexed as A[i*row + j*col]
51 
52   @param[in,out] A  Matrix to apply Householder reflection to, in place
53   @param v          Householder vector
54   @param b          Scaling factor
55   @param m          Number of rows in A
56   @param n          Number of columns in A
57   @param row        Row stride
58   @param col        Col stride
59 
60   @return An error code: 0 - success, otherwise - failure
61 
62   @ref Developer
63 **/
64 static int CeedHouseholderReflect(CeedScalar *A, const CeedScalar *v,
65                                   CeedScalar b, CeedInt m, CeedInt n,
66                                   CeedInt row, CeedInt col) {
67   for (CeedInt j=0; j<n; j++) {
68     CeedScalar w = A[0*row + j*col];
69     for (CeedInt i=1; i<m; i++)
70       w += v[i] * A[i*row + j*col];
71     A[0*row + j*col] -= b * w;
72     for (CeedInt i=1; i<m; i++)
73       A[i*row + j*col] -= b * w * v[i];
74   }
75   return CEED_ERROR_SUCCESS;
76 }
77 
78 /**
79   @brief Apply Householder Q matrix
80 
81     Compute A = Q A where Q is mxm and A is mxn.
82 
83   @param[in,out] A  Matrix to apply Householder Q to, in place
84   @param Q          Householder Q matrix
85   @param tau        Householder scaling factors
86   @param t_mode     Transpose mode for application
87   @param m          Number of rows in A
88   @param n          Number of columns in A
89   @param k          Number of elementary reflectors in Q, k<m
90   @param row        Row stride in A
91   @param col        Col stride in A
92 
93   @return An error code: 0 - success, otherwise - failure
94 
95   @ref Developer
96 **/
97 int CeedHouseholderApplyQ(CeedScalar *A, const CeedScalar *Q,
98                           const CeedScalar *tau, CeedTransposeMode t_mode,
99                           CeedInt m, CeedInt n, CeedInt k,
100                           CeedInt row, CeedInt col) {
101   int ierr;
102   CeedScalar *v;
103   ierr = CeedMalloc(m, &v); CeedChk(ierr);
104   for (CeedInt ii=0; ii<k; ii++) {
105     CeedInt i = t_mode == CEED_TRANSPOSE ? ii : k-1-ii;
106     for (CeedInt j=i+1; j<m; j++)
107       v[j] = Q[j*k+i];
108     // Apply Householder reflector (I - tau v v^T) collo_grad_1d^T
109     ierr = CeedHouseholderReflect(&A[i*row], &v[i], tau[i], m-i, n, row, col);
110     CeedChk(ierr);
111   }
112   ierr = CeedFree(&v); CeedChk(ierr);
113   return CEED_ERROR_SUCCESS;
114 }
115 
116 /**
117   @brief Compute Givens rotation
118 
119     Computes A = G A (or G^T A in transpose mode)
120     where A is an mxn matrix indexed as A[i*n + j*m]
121 
122   @param[in,out] A  Row major matrix to apply Givens rotation to, in place
123   @param c          Cosine factor
124   @param s          Sine factor
125   @param t_mode     @ref CEED_NOTRANSPOSE to rotate the basis counter-clockwise,
126                     which has the effect of rotating columns of A clockwise;
127                     @ref CEED_TRANSPOSE for the opposite rotation
128   @param i          First row/column to apply rotation
129   @param k          Second row/column to apply rotation
130   @param m          Number of rows in A
131   @param n          Number of columns in A
132 
133   @return An error code: 0 - success, otherwise - failure
134 
135   @ref Developer
136 **/
137 static int CeedGivensRotation(CeedScalar *A, CeedScalar c, CeedScalar s,
138                               CeedTransposeMode t_mode, CeedInt i, CeedInt k,
139                               CeedInt m, CeedInt n) {
140   CeedInt stride_j = 1, stride_ik = m, num_its = n;
141   if (t_mode == CEED_NOTRANSPOSE) {
142     stride_j = n; stride_ik = 1; num_its = m;
143   }
144 
145   // Apply rotation
146   for (CeedInt j=0; j<num_its; j++) {
147     CeedScalar tau1 = A[i*stride_ik+j*stride_j], tau2 = A[k*stride_ik+j*stride_j];
148     A[i*stride_ik+j*stride_j] = c*tau1 - s*tau2;
149     A[k*stride_ik+j*stride_j] = s*tau1 + c*tau2;
150   }
151   return CEED_ERROR_SUCCESS;
152 }
153 
154 /**
155   @brief View an array stored in a CeedBasis
156 
157   @param[in] name      Name of array
158   @param[in] fp_fmt    Printing format
159   @param[in] m         Number of rows in array
160   @param[in] n         Number of columns in array
161   @param[in] a         Array to be viewed
162   @param[in] stream    Stream to view to, e.g., stdout
163 
164   @return An error code: 0 - success, otherwise - failure
165 
166   @ref Developer
167 **/
168 static int CeedScalarView(const char *name, const char *fp_fmt, CeedInt m,
169                           CeedInt n, const CeedScalar *a, FILE *stream) {
170   for (int i=0; i<m; i++) {
171     if (m > 1)
172       fprintf(stream, "%12s[%d]:", name, i);
173     else
174       fprintf(stream, "%12s:", name);
175     for (int j=0; j<n; j++)
176       fprintf(stream, fp_fmt, fabs(a[i*n+j]) > 1E-14 ? a[i*n+j] : 0);
177     fputs("\n", stream);
178   }
179   return CEED_ERROR_SUCCESS;
180 }
181 
182 /// @}
183 
184 /// ----------------------------------------------------------------------------
185 /// Ceed Backend API
186 /// ----------------------------------------------------------------------------
187 /// @addtogroup CeedBasisBackend
188 /// @{
189 
190 /**
191   @brief Return collocated grad matrix
192 
193   @param basis               CeedBasis
194   @param[out] collo_grad_1d  Row-major (Q_1d * Q_1d) matrix expressing derivatives of
195                                basis functions at quadrature points
196 
197   @return An error code: 0 - success, otherwise - failure
198 
199   @ref Backend
200 **/
201 int CeedBasisGetCollocatedGrad(CeedBasis basis, CeedScalar *collo_grad_1d) {
202   int i, j, k;
203   Ceed ceed;
204   CeedInt ierr, P_1d=(basis)->P_1d, Q_1d=(basis)->Q_1d;
205   CeedScalar *interp_1d, *grad_1d, *tau;
206 
207   ierr = CeedMalloc(Q_1d*P_1d, &interp_1d); CeedChk(ierr);
208   ierr = CeedMalloc(Q_1d*P_1d, &grad_1d); CeedChk(ierr);
209   ierr = CeedMalloc(Q_1d, &tau); CeedChk(ierr);
210   memcpy(interp_1d, (basis)->interp_1d, Q_1d*P_1d*sizeof(basis)->interp_1d[0]);
211   memcpy(grad_1d, (basis)->grad_1d, Q_1d*P_1d*sizeof(basis)->interp_1d[0]);
212 
213   // QR Factorization, interp_1d = Q R
214   ierr = CeedBasisGetCeed(basis, &ceed); CeedChk(ierr);
215   ierr = CeedQRFactorization(ceed, interp_1d, tau, Q_1d, P_1d); CeedChk(ierr);
216   // Note: This function is for backend use, so all errors are terminal
217   //   and we do not need to clean up memory on failure.
218 
219   // Apply Rinv, collo_grad_1d = grad_1d Rinv
220   for (i=0; i<Q_1d; i++) { // Row i
221     collo_grad_1d[Q_1d*i] = grad_1d[P_1d*i]/interp_1d[0];
222     for (j=1; j<P_1d; j++) { // Column j
223       collo_grad_1d[j+Q_1d*i] = grad_1d[j+P_1d*i];
224       for (k=0; k<j; k++)
225         collo_grad_1d[j+Q_1d*i] -= interp_1d[j+P_1d*k]*collo_grad_1d[k+Q_1d*i];
226       collo_grad_1d[j+Q_1d*i] /= interp_1d[j+P_1d*j];
227     }
228     for (j=P_1d; j<Q_1d; j++)
229       collo_grad_1d[j+Q_1d*i] = 0;
230   }
231 
232   // Apply Qtranspose, collo_grad = collo_grad Q_transpose
233   ierr = CeedHouseholderApplyQ(collo_grad_1d, interp_1d, tau, CEED_NOTRANSPOSE,
234                                Q_1d, Q_1d, P_1d, 1, Q_1d); CeedChk(ierr);
235 
236   ierr = CeedFree(&interp_1d); CeedChk(ierr);
237   ierr = CeedFree(&grad_1d); CeedChk(ierr);
238   ierr = CeedFree(&tau); CeedChk(ierr);
239   return CEED_ERROR_SUCCESS;
240 }
241 
242 /**
243   @brief Get tensor status for given CeedBasis
244 
245   @param basis           CeedBasis
246   @param[out] is_tensor  Variable to store tensor status
247 
248   @return An error code: 0 - success, otherwise - failure
249 
250   @ref Backend
251 **/
252 int CeedBasisIsTensor(CeedBasis basis, bool *is_tensor) {
253   *is_tensor = basis->tensor_basis;
254   return CEED_ERROR_SUCCESS;
255 }
256 
257 /**
258   @brief Get backend data of a CeedBasis
259 
260   @param basis      CeedBasis
261   @param[out] data  Variable to store data
262 
263   @return An error code: 0 - success, otherwise - failure
264 
265   @ref Backend
266 **/
267 int CeedBasisGetData(CeedBasis basis, void *data) {
268   *(void **)data = basis->data;
269   return CEED_ERROR_SUCCESS;
270 }
271 
272 /**
273   @brief Set backend data of a CeedBasis
274 
275   @param[out] basis  CeedBasis
276   @param data        Data to set
277 
278   @return An error code: 0 - success, otherwise - failure
279 
280   @ref Backend
281 **/
282 int CeedBasisSetData(CeedBasis basis, void *data) {
283   basis->data = data;
284   return CEED_ERROR_SUCCESS;
285 }
286 
287 /**
288   @brief Increment the reference counter for a CeedBasis
289 
290   @param basis  Basis to increment the reference counter
291 
292   @return An error code: 0 - success, otherwise - failure
293 
294   @ref Backend
295 **/
296 int CeedBasisReference(CeedBasis basis) {
297   basis->ref_count++;
298   return CEED_ERROR_SUCCESS;
299 }
300 
301 /**
302   @brief Get dimension for given CeedElemTopology
303 
304   @param topo      CeedElemTopology
305   @param[out] dim  Variable to store dimension of topology
306 
307   @return An error code: 0 - success, otherwise - failure
308 
309   @ref Backend
310 **/
311 int CeedBasisGetTopologyDimension(CeedElemTopology topo, CeedInt *dim) {
312   *dim = (CeedInt) topo >> 16;
313   return CEED_ERROR_SUCCESS;
314 }
315 
316 /**
317   @brief Get CeedTensorContract of a CeedBasis
318 
319   @param basis          CeedBasis
320   @param[out] contract  Variable to store CeedTensorContract
321 
322   @return An error code: 0 - success, otherwise - failure
323 
324   @ref Backend
325 **/
326 int CeedBasisGetTensorContract(CeedBasis basis, CeedTensorContract *contract) {
327   *contract = basis->contract;
328   return CEED_ERROR_SUCCESS;
329 }
330 
331 /**
332   @brief Set CeedTensorContract of a CeedBasis
333 
334   @param[out] basis  CeedBasis
335   @param contract    CeedTensorContract to set
336 
337   @return An error code: 0 - success, otherwise - failure
338 
339   @ref Backend
340 **/
341 int CeedBasisSetTensorContract(CeedBasis basis, CeedTensorContract contract) {
342   int ierr;
343   basis->contract = contract;
344   ierr = CeedTensorContractReference(contract); CeedChk(ierr);
345   return CEED_ERROR_SUCCESS;
346 }
347 
348 /**
349   @brief Return a reference implementation of matrix multiplication C = A B.
350            Note, this is a reference implementation for CPU CeedScalar pointers
351            that is not intended for high performance.
352 
353   @param ceed        A Ceed context for error handling
354   @param[in] mat_A   Row-major matrix A
355   @param[in] mat_B   Row-major matrix B
356   @param[out] mat_C  Row-major output matrix C
357   @param m           Number of rows of C
358   @param n           Number of columns of C
359   @param kk          Number of columns of A/rows of B
360 
361   @return An error code: 0 - success, otherwise - failure
362 
363   @ref Utility
364 **/
365 int CeedMatrixMultiply(Ceed ceed, const CeedScalar *mat_A,
366                        const CeedScalar *mat_B, CeedScalar *mat_C, CeedInt m,
367                        CeedInt n, CeedInt kk) {
368   for (CeedInt i=0; i<m; i++)
369     for (CeedInt j=0; j<n; j++) {
370       CeedScalar sum = 0;
371       for (CeedInt k=0; k<kk; k++)
372         sum += mat_A[k+i*kk]*mat_B[j+k*n];
373       mat_C[j+i*n] = sum;
374     }
375   return CEED_ERROR_SUCCESS;
376 }
377 
378 /// @}
379 
380 /// ----------------------------------------------------------------------------
381 /// CeedBasis Public API
382 /// ----------------------------------------------------------------------------
383 /// @addtogroup CeedBasisUser
384 /// @{
385 
386 /**
387   @brief Create a tensor-product basis for H^1 discretizations
388 
389   @param ceed        A Ceed object where the CeedBasis will be created
390   @param dim         Topological dimension
391   @param num_comp    Number of field components (1 for scalar fields)
392   @param P_1d        Number of nodes in one dimension
393   @param Q_1d        Number of quadrature points in one dimension
394   @param interp_1d   Row-major (Q_1d * P_1d) matrix expressing the values of nodal
395                        basis functions at quadrature points
396   @param grad_1d     Row-major (Q_1d * P_1d) matrix expressing derivatives of nodal
397                        basis functions at quadrature points
398   @param q_ref_1d    Array of length Q_1d holding the locations of quadrature points
399                        on the 1D reference element [-1, 1]
400   @param q_weight_1d Array of length Q_1d holding the quadrature weights on the
401                        reference element
402   @param[out] basis  Address of the variable where the newly created
403                        CeedBasis will be stored.
404 
405   @return An error code: 0 - success, otherwise - failure
406 
407   @ref User
408 **/
409 int CeedBasisCreateTensorH1(Ceed ceed, CeedInt dim, CeedInt num_comp,
410                             CeedInt P_1d, CeedInt Q_1d,
411                             const CeedScalar *interp_1d,
412                             const CeedScalar *grad_1d, const CeedScalar *q_ref_1d,
413                             const CeedScalar *q_weight_1d, CeedBasis *basis) {
414   int ierr;
415 
416   if (!ceed->BasisCreateTensorH1) {
417     Ceed delegate;
418     ierr = CeedGetObjectDelegate(ceed, &delegate, "Basis"); CeedChk(ierr);
419 
420     if (!delegate)
421       // LCOV_EXCL_START
422       return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
423                        "Backend does not support BasisCreateTensorH1");
424     // LCOV_EXCL_STOP
425 
426     ierr = CeedBasisCreateTensorH1(delegate, dim, num_comp, P_1d,
427                                    Q_1d, interp_1d, grad_1d, q_ref_1d,
428                                    q_weight_1d, basis); CeedChk(ierr);
429     return CEED_ERROR_SUCCESS;
430   }
431 
432   if (dim<1)
433     // LCOV_EXCL_START
434     return CeedError(ceed, CEED_ERROR_DIMENSION,
435                      "Basis dimension must be a positive value");
436   // LCOV_EXCL_STOP
437   CeedElemTopology topo = dim == 1 ? CEED_TOPOLOGY_LINE
438                           : dim == 2 ? CEED_TOPOLOGY_QUAD
439                           : CEED_TOPOLOGY_HEX;
440 
441   ierr = CeedCalloc(1, basis); CeedChk(ierr);
442   (*basis)->ceed = ceed;
443   ierr = CeedReference(ceed); CeedChk(ierr);
444   (*basis)->ref_count = 1;
445   (*basis)->tensor_basis = 1;
446   (*basis)->dim = dim;
447   (*basis)->topo = topo;
448   (*basis)->num_comp = num_comp;
449   (*basis)->P_1d = P_1d;
450   (*basis)->Q_1d = Q_1d;
451   (*basis)->P = CeedIntPow(P_1d, dim);
452   (*basis)->Q = CeedIntPow(Q_1d, dim);
453   (*basis)->Q_comp = 1;
454   (*basis)->basis_space = 1; // 1 for H^1 space
455   ierr = CeedCalloc(Q_1d, &(*basis)->q_ref_1d); CeedChk(ierr);
456   ierr = CeedCalloc(Q_1d, &(*basis)->q_weight_1d); CeedChk(ierr);
457   if (q_ref_1d) memcpy((*basis)->q_ref_1d, q_ref_1d, Q_1d*sizeof(q_ref_1d[0]));
458   if (q_weight_1d) memcpy((*basis)->q_weight_1d, q_weight_1d,
459                             Q_1d*sizeof(q_weight_1d[0]));
460   ierr = CeedCalloc(Q_1d*P_1d, &(*basis)->interp_1d); CeedChk(ierr);
461   ierr = CeedCalloc(Q_1d*P_1d, &(*basis)->grad_1d); CeedChk(ierr);
462   if (interp_1d) memcpy((*basis)->interp_1d, interp_1d,
463                           Q_1d*P_1d*sizeof(interp_1d[0]));
464   if (grad_1d) memcpy((*basis)->grad_1d, grad_1d, Q_1d*P_1d*sizeof(grad_1d[0]));
465   ierr = ceed->BasisCreateTensorH1(dim, P_1d, Q_1d, interp_1d, grad_1d, q_ref_1d,
466                                    q_weight_1d, *basis); CeedChk(ierr);
467   return CEED_ERROR_SUCCESS;
468 }
469 
470 /**
471   @brief Create a tensor-product Lagrange basis
472 
473   @param ceed        A Ceed object where the CeedBasis will be created
474   @param dim         Topological dimension of element
475   @param num_comp      Number of field components (1 for scalar fields)
476   @param P           Number of Gauss-Lobatto nodes in one dimension.  The
477                        polynomial degree of the resulting Q_k element is k=P-1.
478   @param Q           Number of quadrature points in one dimension.
479   @param quad_mode   Distribution of the Q quadrature points (affects order of
480                        accuracy for the quadrature)
481   @param[out] basis  Address of the variable where the newly created
482                        CeedBasis will be stored.
483 
484   @return An error code: 0 - success, otherwise - failure
485 
486   @ref User
487 **/
488 int CeedBasisCreateTensorH1Lagrange(Ceed ceed, CeedInt dim, CeedInt num_comp,
489                                     CeedInt P, CeedInt Q, CeedQuadMode quad_mode,
490                                     CeedBasis *basis) {
491   // Allocate
492   int ierr, ierr2, i, j, k;
493   CeedScalar c1, c2, c3, c4, dx, *nodes, *interp_1d, *grad_1d, *q_ref_1d,
494              *q_weight_1d;
495 
496   if (dim<1)
497     // LCOV_EXCL_START
498     return CeedError(ceed, CEED_ERROR_DIMENSION,
499                      "Basis dimension must be a positive value");
500   // LCOV_EXCL_STOP
501 
502   // Get Nodes and Weights
503   ierr = CeedCalloc(P*Q, &interp_1d); CeedChk(ierr);
504   ierr = CeedCalloc(P*Q, &grad_1d); CeedChk(ierr);
505   ierr = CeedCalloc(P, &nodes); CeedChk(ierr);
506   ierr = CeedCalloc(Q, &q_ref_1d); CeedChk(ierr);
507   ierr = CeedCalloc(Q, &q_weight_1d); CeedChk(ierr);
508   ierr = CeedLobattoQuadrature(P, nodes, NULL);
509   if (ierr) { goto cleanup; } CeedChk(ierr);
510   switch (quad_mode) {
511   case CEED_GAUSS:
512     ierr = CeedGaussQuadrature(Q, q_ref_1d, q_weight_1d);
513     break;
514   case CEED_GAUSS_LOBATTO:
515     ierr = CeedLobattoQuadrature(Q, q_ref_1d, q_weight_1d);
516     break;
517   }
518   if (ierr) { goto cleanup; } CeedChk(ierr);
519 
520   // Build B, D matrix
521   // Fornberg, 1998
522   for (i = 0; i  < Q; i++) {
523     c1 = 1.0;
524     c3 = nodes[0] - q_ref_1d[i];
525     interp_1d[i*P+0] = 1.0;
526     for (j = 1; j < P; j++) {
527       c2 = 1.0;
528       c4 = c3;
529       c3 = nodes[j] - q_ref_1d[i];
530       for (k = 0; k < j; k++) {
531         dx = nodes[j] - nodes[k];
532         c2 *= dx;
533         if (k == j - 1) {
534           grad_1d[i*P + j] = c1*(interp_1d[i*P + k] - c4*grad_1d[i*P + k]) / c2;
535           interp_1d[i*P + j] = - c1*c4*interp_1d[i*P + k] / c2;
536         }
537         grad_1d[i*P + k] = (c3*grad_1d[i*P + k] - interp_1d[i*P + k]) / dx;
538         interp_1d[i*P + k] = c3*interp_1d[i*P + k] / dx;
539       }
540       c1 = c2;
541     }
542   }
543   // Pass to CeedBasisCreateTensorH1
544   ierr = CeedBasisCreateTensorH1(ceed, dim, num_comp, P, Q, interp_1d, grad_1d,
545                                  q_ref_1d, q_weight_1d, basis); CeedChk(ierr);
546 cleanup:
547   ierr2 = CeedFree(&interp_1d); CeedChk(ierr2);
548   ierr2 = CeedFree(&grad_1d); CeedChk(ierr2);
549   ierr2 = CeedFree(&nodes); CeedChk(ierr2);
550   ierr2 = CeedFree(&q_ref_1d); CeedChk(ierr2);
551   ierr2 = CeedFree(&q_weight_1d); CeedChk(ierr2);
552   CeedChk(ierr);
553   return CEED_ERROR_SUCCESS;
554 }
555 
556 /**
557   @brief Create a non tensor-product basis for H^1 discretizations
558 
559   @param ceed        A Ceed object where the CeedBasis will be created
560   @param topo        Topology of element, e.g. hypercube, simplex, ect
561   @param num_comp    Number of field components (1 for scalar fields)
562   @param num_nodes   Total number of nodes
563   @param num_qpts    Total number of quadrature points
564   @param interp      Row-major (num_qpts * num_nodes) matrix expressing the values of
565                        nodal basis functions at quadrature points
566   @param grad        Row-major (num_qpts * dim * num_nodes) matrix expressing
567                        derivatives of nodal basis functions at quadrature points
568   @param q_ref       Array of length num_qpts holding the locations of quadrature
569                        points on the reference element
570   @param q_weight    Array of length num_qpts holding the quadrature weights on the
571                        reference element
572   @param[out] basis  Address of the variable where the newly created
573                        CeedBasis will be stored.
574 
575   @return An error code: 0 - success, otherwise - failure
576 
577   @ref User
578 **/
579 int CeedBasisCreateH1(Ceed ceed, CeedElemTopology topo, CeedInt num_comp,
580                       CeedInt num_nodes, CeedInt num_qpts, const CeedScalar *interp,
581                       const CeedScalar *grad, const CeedScalar *q_ref,
582                       const CeedScalar *q_weight, CeedBasis *basis) {
583   int ierr;
584   CeedInt P = num_nodes, Q = num_qpts, dim = 0;
585 
586   if (!ceed->BasisCreateH1) {
587     Ceed delegate;
588     ierr = CeedGetObjectDelegate(ceed, &delegate, "Basis"); CeedChk(ierr);
589 
590     if (!delegate)
591       // LCOV_EXCL_START
592       return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
593                        "Backend does not support BasisCreateH1");
594     // LCOV_EXCL_STOP
595 
596     ierr = CeedBasisCreateH1(delegate, topo, num_comp, num_nodes,
597                              num_qpts, interp, grad, q_ref,
598                              q_weight, basis); CeedChk(ierr);
599     return CEED_ERROR_SUCCESS;
600   }
601 
602   ierr = CeedCalloc(1, basis); CeedChk(ierr);
603 
604   ierr = CeedBasisGetTopologyDimension(topo, &dim); CeedChk(ierr);
605 
606   (*basis)->ceed = ceed;
607   ierr = CeedReference(ceed); CeedChk(ierr);
608   (*basis)->ref_count = 1;
609   (*basis)->tensor_basis = 0;
610   (*basis)->dim = dim;
611   (*basis)->topo = topo;
612   (*basis)->num_comp = num_comp;
613   (*basis)->P = P;
614   (*basis)->Q = Q;
615   (*basis)->Q_comp = 1;
616   (*basis)->basis_space = 1; // 1 for H^1 space
617   ierr = CeedCalloc(Q*dim, &(*basis)->q_ref_1d); CeedChk(ierr);
618   ierr = CeedCalloc(Q, &(*basis)->q_weight_1d); CeedChk(ierr);
619   if (q_ref) memcpy((*basis)->q_ref_1d, q_ref, Q*dim*sizeof(q_ref[0]));
620   if(q_weight) memcpy((*basis)->q_weight_1d, q_weight, Q*sizeof(q_weight[0]));
621   ierr = CeedCalloc(Q*P, &(*basis)->interp); CeedChk(ierr);
622   ierr = CeedCalloc(dim*Q*P, &(*basis)->grad); CeedChk(ierr);
623   if(interp) memcpy((*basis)->interp, interp, Q*P*sizeof(interp[0]));
624   if(grad) memcpy((*basis)->grad, grad, dim*Q*P*sizeof(grad[0]));
625   ierr = ceed->BasisCreateH1(topo, dim, P, Q, interp, grad, q_ref,
626                              q_weight, *basis); CeedChk(ierr);
627   return CEED_ERROR_SUCCESS;
628 }
629 
630 /**
631   @brief Create a non tensor-product basis for H(div) discretizations
632 
633   @param ceed        A Ceed object where the CeedBasis will be created
634   @param topo        Topology of element (`CEED_TOPOLOGY_QUAD`, `CEED_TOPOLOGY_PRISM`, etc.),
635                      dimension of which is used in some array sizes below
636   @param num_comp    Number of components (usually 1 for vectors in H(div) bases)
637   @param num_nodes   Total number of nodes (dofs per element)
638   @param num_qpts    Total number of quadrature points
639   @param interp      Row-major (dim*num_qpts * num_nodes) matrix expressing the values of
640                        nodal basis functions at quadrature points
641   @param div        Row-major (num_qpts * num_nodes) matrix expressing
642                        divergence of nodal basis functions at quadrature points
643   @param q_ref       Array of length num_qpts holding the locations of quadrature
644                        points on the reference element
645   @param q_weight    Array of length num_qpts holding the quadrature weights on the
646                        reference element
647   @param[out] basis  Address of the variable where the newly created
648                        CeedBasis will be stored.
649 
650   @return An error code: 0 - success, otherwise - failure
651 
652   @ref User
653 **/
654 int CeedBasisCreateHdiv(Ceed ceed, CeedElemTopology topo, CeedInt num_comp,
655                         CeedInt num_nodes, CeedInt num_qpts, const CeedScalar *interp,
656                         const CeedScalar *div, const CeedScalar *q_ref,
657                         const CeedScalar *q_weight, CeedBasis *basis) {
658   int ierr;
659   CeedInt Q = num_qpts, P = num_nodes, dim = 0;
660   ierr = CeedBasisGetTopologyDimension(topo, &dim); CeedChk(ierr);
661   if (!ceed->BasisCreateHdiv) {
662     Ceed delegate;
663     ierr = CeedGetObjectDelegate(ceed, &delegate, "Basis"); CeedChk(ierr);
664 
665     if (!delegate)
666       // LCOV_EXCL_START
667       return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
668                        "Backend does not implement BasisCreateHdiv");
669     // LCOV_EXCL_STOP
670 
671     ierr = CeedBasisCreateHdiv(delegate, topo, num_comp, num_nodes,
672                                num_qpts, interp, div, q_ref,
673                                q_weight, basis); CeedChk(ierr);
674     return CEED_ERROR_SUCCESS;
675   }
676 
677   ierr = CeedCalloc(1, basis); CeedChk(ierr);
678 
679   (*basis)->ceed = ceed;
680   ierr = CeedReference(ceed); CeedChk(ierr);
681   (*basis)->ref_count = 1;
682   (*basis)->tensor_basis = 0;
683   (*basis)->dim = dim;
684   (*basis)->topo = topo;
685   (*basis)->num_comp = num_comp;
686   (*basis)->P = P;
687   (*basis)->Q = Q;
688   (*basis)->Q_comp = dim;
689   (*basis)->basis_space = 2; // 2 for H(div) space
690   ierr = CeedMalloc(Q*dim, &(*basis)->q_ref_1d); CeedChk(ierr);
691   ierr = CeedMalloc(Q, &(*basis)->q_weight_1d); CeedChk(ierr);
692   if (q_ref) memcpy((*basis)->q_ref_1d, q_ref, Q*dim*sizeof(q_ref[0]));
693   if (q_weight) memcpy((*basis)->q_weight_1d, q_weight, Q*sizeof(q_weight[0]));
694   ierr = CeedMalloc(dim*Q*P, &(*basis)->interp); CeedChk(ierr);
695   ierr = CeedMalloc(Q*P, &(*basis)->div); CeedChk(ierr);
696   if (interp) memcpy((*basis)->interp, interp, dim*Q*P*sizeof(interp[0]));
697   if (div) memcpy((*basis)->div, div, Q*P*sizeof(div[0]));
698   ierr = ceed->BasisCreateHdiv(topo, dim, P, Q, interp, div, q_ref,
699                                q_weight, *basis); CeedChk(ierr);
700   return CEED_ERROR_SUCCESS;
701 }
702 
703 /**
704   @brief Copy the pointer to a CeedBasis. Both pointers should
705            be destroyed with `CeedBasisDestroy()`;
706            Note: If `*basis_copy` is non-NULL, then it is assumed that
707            `*basis_copy` is a pointer to a CeedBasis. This CeedBasis
708            will be destroyed if `*basis_copy` is the only
709            reference to this CeedBasis.
710 
711   @param basis            CeedBasis to copy reference to
712   @param[out] basis_copy  Variable to store copied reference
713 
714   @return An error code: 0 - success, otherwise - failure
715 
716   @ref User
717 **/
718 int CeedBasisReferenceCopy(CeedBasis basis, CeedBasis *basis_copy) {
719   int ierr;
720 
721   ierr = CeedBasisReference(basis); CeedChk(ierr);
722   ierr = CeedBasisDestroy(basis_copy); CeedChk(ierr);
723   *basis_copy = basis;
724   return CEED_ERROR_SUCCESS;
725 }
726 
727 /**
728   @brief View a CeedBasis
729 
730   @param basis   CeedBasis to view
731   @param stream  Stream to view to, e.g., stdout
732 
733   @return An error code: 0 - success, otherwise - failure
734 
735   @ref User
736 **/
737 int CeedBasisView(CeedBasis basis, FILE *stream) {
738   int ierr;
739   CeedFESpace FE_space = basis->basis_space;
740   CeedElemTopology topo = basis->topo;
741   // Print FE space and element topology of the basis
742   if (basis->tensor_basis) {
743     fprintf(stream, "CeedBasis (%s on a %s element): dim=%d P=%d Q=%d\n",
744             CeedFESpaces[FE_space], CeedElemTopologies[topo],
745             basis->dim, basis->P_1d, basis->Q_1d);
746   } else {
747     fprintf(stream, "CeedBasis (%s on a %s element): dim=%d P=%d Q=%d\n",
748             CeedFESpaces[FE_space], CeedElemTopologies[topo],
749             basis->dim, basis->P, basis->Q);
750   }
751   // Print quadrature data, interpolation/gradient/divergene/curl of the basis
752   if (basis->tensor_basis) { // tensor basis
753     ierr = CeedScalarView("qref1d", "\t% 12.8f", 1, basis->Q_1d, basis->q_ref_1d,
754                           stream); CeedChk(ierr);
755     ierr = CeedScalarView("qweight1d", "\t% 12.8f", 1, basis->Q_1d,
756                           basis->q_weight_1d, stream); CeedChk(ierr);
757     ierr = CeedScalarView("interp1d", "\t% 12.8f", basis->Q_1d, basis->P_1d,
758                           basis->interp_1d, stream); CeedChk(ierr);
759     ierr = CeedScalarView("grad1d", "\t% 12.8f", basis->Q_1d, basis->P_1d,
760                           basis->grad_1d, stream); CeedChk(ierr);
761   } else { // non-tensor basis
762     ierr = CeedScalarView("qref", "\t% 12.8f", 1, basis->Q*basis->dim,
763                           basis->q_ref_1d,
764                           stream); CeedChk(ierr);
765     ierr = CeedScalarView("qweight", "\t% 12.8f", 1, basis->Q, basis->q_weight_1d,
766                           stream); CeedChk(ierr);
767     ierr = CeedScalarView("interp", "\t% 12.8f", basis->Q_comp*basis->Q, basis->P,
768                           basis->interp, stream); CeedChk(ierr);
769     if (basis->grad) {
770       ierr = CeedScalarView("grad", "\t% 12.8f", basis->dim*basis->Q, basis->P,
771                             basis->grad, stream); CeedChk(ierr);
772     }
773     if (basis->div) {
774       ierr = CeedScalarView("div", "\t% 12.8f", basis->Q, basis->P,
775                             basis->div, stream); CeedChk(ierr);
776     }
777   }
778   return CEED_ERROR_SUCCESS;
779 }
780 
781 /**
782   @brief Apply basis evaluation from nodes to quadrature points or vice versa
783 
784   @param basis     CeedBasis to evaluate
785   @param num_elem  The number of elements to apply the basis evaluation to;
786                      the backend will specify the ordering in
787                      CeedElemRestrictionCreateBlocked()
788   @param t_mode    \ref CEED_NOTRANSPOSE to evaluate from nodes to quadrature
789                      points, \ref CEED_TRANSPOSE to apply the transpose, mapping
790                      from quadrature points to nodes
791   @param eval_mode \ref CEED_EVAL_NONE to use values directly,
792                      \ref CEED_EVAL_INTERP to use interpolated values,
793                      \ref CEED_EVAL_GRAD to use gradients,
794                      \ref CEED_EVAL_WEIGHT to use quadrature weights.
795   @param[in] u     Input CeedVector
796   @param[out] v    Output CeedVector
797 
798   @return An error code: 0 - success, otherwise - failure
799 
800   @ref User
801 **/
802 int CeedBasisApply(CeedBasis basis, CeedInt num_elem, CeedTransposeMode t_mode,
803                    CeedEvalMode eval_mode, CeedVector u, CeedVector v) {
804   int ierr;
805   CeedInt u_length = 0, v_length, dim, num_comp, num_nodes, num_qpts;
806   ierr = CeedBasisGetDimension(basis, &dim); CeedChk(ierr);
807   ierr = CeedBasisGetNumComponents(basis, &num_comp); CeedChk(ierr);
808   ierr = CeedBasisGetNumNodes(basis, &num_nodes); CeedChk(ierr);
809   ierr = CeedBasisGetNumQuadraturePoints(basis, &num_qpts); CeedChk(ierr);
810   ierr = CeedVectorGetLength(v, &v_length); CeedChk(ierr);
811   if (u) {
812     ierr = CeedVectorGetLength(u, &u_length); CeedChk(ierr);
813   }
814 
815   if (!basis->Apply)
816     // LCOV_EXCL_START
817     return CeedError(basis->ceed, CEED_ERROR_UNSUPPORTED,
818                      "Backend does not support BasisApply");
819   // LCOV_EXCL_STOP
820 
821   // Check compatibility of topological and geometrical dimensions
822   if ((t_mode == CEED_TRANSPOSE && (v_length%num_nodes != 0 ||
823                                     u_length%num_qpts != 0)) ||
824       (t_mode == CEED_NOTRANSPOSE && (u_length%num_nodes != 0 ||
825                                       v_length%num_qpts != 0)))
826     // LCOV_EXCL_START
827     return CeedError(basis->ceed, CEED_ERROR_DIMENSION,
828                      "Length of input/output vectors "
829                      "incompatible with basis dimensions");
830   // LCOV_EXCL_STOP
831 
832   // Check vector lengths to prevent out of bounds issues
833   bool bad_dims = false;
834   switch (eval_mode) {
835   case CEED_EVAL_NONE:
836   case CEED_EVAL_INTERP: bad_dims =
837       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
838                                      v_length < num_elem*num_comp*num_nodes)) ||
839        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
840                                        u_length < num_elem*num_comp*num_nodes)));
841     break;
842   case CEED_EVAL_GRAD: bad_dims =
843       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts*dim ||
844                                      v_length < num_elem*num_comp*num_nodes)) ||
845        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp*dim ||
846                                        u_length < num_elem*num_comp*num_nodes)));
847     break;
848   case CEED_EVAL_WEIGHT:
849     bad_dims = v_length < num_elem*num_qpts;
850     break;
851   // LCOV_EXCL_START
852   case CEED_EVAL_DIV: bad_dims =
853       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
854                                      v_length < num_elem*num_comp*num_nodes)) ||
855        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
856                                        u_length < num_elem*num_comp*num_nodes)));
857     break;
858   case CEED_EVAL_CURL: bad_dims =
859       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
860                                      v_length < num_elem*num_comp*num_nodes)) ||
861        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
862                                        u_length < num_elem*num_comp*num_nodes)));
863     break;
864     // LCOV_EXCL_STOP
865   }
866   if (bad_dims)
867     // LCOV_EXCL_START
868     return CeedError(basis->ceed, CEED_ERROR_DIMENSION,
869                      "Input/output vectors too short for basis and evaluation mode");
870   // LCOV_EXCL_STOP
871 
872   ierr = basis->Apply(basis, num_elem, t_mode, eval_mode, u, v); CeedChk(ierr);
873   return CEED_ERROR_SUCCESS;
874 }
875 
876 /**
877   @brief Get Ceed associated with a CeedBasis
878 
879   @param basis      CeedBasis
880   @param[out] ceed  Variable to store Ceed
881 
882   @return An error code: 0 - success, otherwise - failure
883 
884   @ref Advanced
885 **/
886 int CeedBasisGetCeed(CeedBasis basis, Ceed *ceed) {
887   *ceed = basis->ceed;
888   return CEED_ERROR_SUCCESS;
889 }
890 
891 /**
892   @brief Get dimension for given CeedBasis
893 
894   @param basis     CeedBasis
895   @param[out] dim  Variable to store dimension of basis
896 
897   @return An error code: 0 - success, otherwise - failure
898 
899   @ref Advanced
900 **/
901 int CeedBasisGetDimension(CeedBasis basis, CeedInt *dim) {
902   *dim = basis->dim;
903   return CEED_ERROR_SUCCESS;
904 }
905 
906 /**
907   @brief Get topology for given CeedBasis
908 
909   @param basis      CeedBasis
910   @param[out] topo  Variable to store topology of basis
911 
912   @return An error code: 0 - success, otherwise - failure
913 
914   @ref Advanced
915 **/
916 int CeedBasisGetTopology(CeedBasis basis, CeedElemTopology *topo) {
917   *topo = basis->topo;
918   return CEED_ERROR_SUCCESS;
919 }
920 
921 /**
922   @brief Get number of Q-vector components for given CeedBasis
923 
924   @param basis          CeedBasis
925   @param[out] Q_comp  Variable to store number of Q-vector components of basis
926 
927   @return An error code: 0 - success, otherwise - failure
928 
929   @ref Advanced
930 **/
931 int CeedBasisGetNumQuadratureComponents(CeedBasis basis, CeedInt *Q_comp) {
932   *Q_comp = basis->Q_comp;
933   return CEED_ERROR_SUCCESS;
934 }
935 
936 /**
937   @brief Get number of components for given CeedBasis
938 
939   @param basis          CeedBasis
940   @param[out] num_comp  Variable to store number of components of basis
941 
942   @return An error code: 0 - success, otherwise - failure
943 
944   @ref Advanced
945 **/
946 int CeedBasisGetNumComponents(CeedBasis basis, CeedInt *num_comp) {
947   *num_comp = basis->num_comp;
948   return CEED_ERROR_SUCCESS;
949 }
950 
951 /**
952   @brief Get total number of nodes (in dim dimensions) of a CeedBasis
953 
954   @param basis   CeedBasis
955   @param[out] P  Variable to store number of nodes
956 
957   @return An error code: 0 - success, otherwise - failure
958 
959   @ref Utility
960 **/
961 int CeedBasisGetNumNodes(CeedBasis basis, CeedInt *P) {
962   *P = basis->P;
963   return CEED_ERROR_SUCCESS;
964 }
965 
966 /**
967   @brief Get total number of nodes (in 1 dimension) of a CeedBasis
968 
969   @param basis     CeedBasis
970   @param[out] P_1d  Variable to store number of nodes
971 
972   @return An error code: 0 - success, otherwise - failure
973 
974   @ref Advanced
975 **/
976 int CeedBasisGetNumNodes1D(CeedBasis basis, CeedInt *P_1d) {
977   if (!basis->tensor_basis)
978     // LCOV_EXCL_START
979     return CeedError(basis->ceed, CEED_ERROR_MINOR,
980                      "Cannot supply P_1d for non-tensor basis");
981   // LCOV_EXCL_STOP
982 
983   *P_1d = basis->P_1d;
984   return CEED_ERROR_SUCCESS;
985 }
986 
987 /**
988   @brief Get total number of quadrature points (in dim dimensions) of a CeedBasis
989 
990   @param basis   CeedBasis
991   @param[out] Q  Variable to store number of quadrature points
992 
993   @return An error code: 0 - success, otherwise - failure
994 
995   @ref Utility
996 **/
997 int CeedBasisGetNumQuadraturePoints(CeedBasis basis, CeedInt *Q) {
998   *Q = basis->Q;
999   return CEED_ERROR_SUCCESS;
1000 }
1001 
1002 /**
1003   @brief Get total number of quadrature points (in 1 dimension) of a CeedBasis
1004 
1005   @param basis      CeedBasis
1006   @param[out] Q_1d  Variable to store number of quadrature points
1007 
1008   @return An error code: 0 - success, otherwise - failure
1009 
1010   @ref Advanced
1011 **/
1012 int CeedBasisGetNumQuadraturePoints1D(CeedBasis basis, CeedInt *Q_1d) {
1013   if (!basis->tensor_basis)
1014     // LCOV_EXCL_START
1015     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1016                      "Cannot supply Q_1d for non-tensor basis");
1017   // LCOV_EXCL_STOP
1018 
1019   *Q_1d = basis->Q_1d;
1020   return CEED_ERROR_SUCCESS;
1021 }
1022 
1023 /**
1024   @brief Get reference coordinates of quadrature points (in dim dimensions)
1025          of a CeedBasis
1026 
1027   @param basis       CeedBasis
1028   @param[out] q_ref  Variable to store reference coordinates of quadrature points
1029 
1030   @return An error code: 0 - success, otherwise - failure
1031 
1032   @ref Advanced
1033 **/
1034 int CeedBasisGetQRef(CeedBasis basis, const CeedScalar **q_ref) {
1035   *q_ref = basis->q_ref_1d;
1036   return CEED_ERROR_SUCCESS;
1037 }
1038 
1039 /**
1040   @brief Get quadrature weights of quadrature points (in dim dimensions)
1041          of a CeedBasis
1042 
1043   @param basis          CeedBasis
1044   @param[out] q_weight  Variable to store quadrature weights
1045 
1046   @return An error code: 0 - success, otherwise - failure
1047 
1048   @ref Advanced
1049 **/
1050 int CeedBasisGetQWeights(CeedBasis basis, const CeedScalar **q_weight) {
1051   *q_weight = basis->q_weight_1d;
1052   return CEED_ERROR_SUCCESS;
1053 }
1054 
1055 /**
1056   @brief Get interpolation matrix of a CeedBasis
1057 
1058   @param basis        CeedBasis
1059   @param[out] interp  Variable to store interpolation matrix
1060 
1061   @return An error code: 0 - success, otherwise - failure
1062 
1063   @ref Advanced
1064 **/
1065 int CeedBasisGetInterp(CeedBasis basis, const CeedScalar **interp) {
1066   if (!basis->interp && basis->tensor_basis) {
1067     // Allocate
1068     int ierr;
1069     ierr = CeedMalloc(basis->Q*basis->P, &basis->interp); CeedChk(ierr);
1070 
1071     // Initialize
1072     for (CeedInt i=0; i<basis->Q*basis->P; i++)
1073       basis->interp[i] = 1.0;
1074 
1075     // Calculate
1076     for (CeedInt d=0; d<basis->dim; d++)
1077       for (CeedInt qpt=0; qpt<basis->Q; qpt++)
1078         for (CeedInt node=0; node<basis->P; node++) {
1079           CeedInt p = (node / CeedIntPow(basis->P_1d, d)) % basis->P_1d;
1080           CeedInt q = (qpt / CeedIntPow(basis->Q_1d, d)) % basis->Q_1d;
1081           basis->interp[qpt*(basis->P)+node] *= basis->interp_1d[q*basis->P_1d+p];
1082         }
1083   }
1084   *interp = basis->interp;
1085   return CEED_ERROR_SUCCESS;
1086 }
1087 
1088 /**
1089   @brief Get 1D interpolation matrix of a tensor product CeedBasis
1090 
1091   @param basis           CeedBasis
1092   @param[out] interp_1d  Variable to store interpolation matrix
1093 
1094   @return An error code: 0 - success, otherwise - failure
1095 
1096   @ref Backend
1097 **/
1098 int CeedBasisGetInterp1D(CeedBasis basis, const CeedScalar **interp_1d) {
1099   if (!basis->tensor_basis)
1100     // LCOV_EXCL_START
1101     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1102                      "CeedBasis is not a tensor product basis.");
1103   // LCOV_EXCL_STOP
1104 
1105   *interp_1d = basis->interp_1d;
1106   return CEED_ERROR_SUCCESS;
1107 }
1108 
1109 /**
1110   @brief Get gradient matrix of a CeedBasis
1111 
1112   @param basis      CeedBasis
1113   @param[out] grad  Variable to store gradient matrix
1114 
1115   @return An error code: 0 - success, otherwise - failure
1116 
1117   @ref Advanced
1118 **/
1119 int CeedBasisGetGrad(CeedBasis basis, const CeedScalar **grad) {
1120   if (!basis->grad && basis->tensor_basis) {
1121     // Allocate
1122     int ierr;
1123     ierr = CeedMalloc(basis->dim*basis->Q*basis->P, &basis->grad);
1124     CeedChk(ierr);
1125 
1126     // Initialize
1127     for (CeedInt i=0; i<basis->dim*basis->Q*basis->P; i++)
1128       basis->grad[i] = 1.0;
1129 
1130     // Calculate
1131     for (CeedInt d=0; d<basis->dim; d++)
1132       for (CeedInt i=0; i<basis->dim; i++)
1133         for (CeedInt qpt=0; qpt<basis->Q; qpt++)
1134           for (CeedInt node=0; node<basis->P; node++) {
1135             CeedInt p = (node / CeedIntPow(basis->P_1d, d)) % basis->P_1d;
1136             CeedInt q = (qpt / CeedIntPow(basis->Q_1d, d)) % basis->Q_1d;
1137             if (i == d)
1138               basis->grad[(i*basis->Q+qpt)*(basis->P)+node] *=
1139                 basis->grad_1d[q*basis->P_1d+p];
1140             else
1141               basis->grad[(i*basis->Q+qpt)*(basis->P)+node] *=
1142                 basis->interp_1d[q*basis->P_1d+p];
1143           }
1144   }
1145   *grad = basis->grad;
1146   return CEED_ERROR_SUCCESS;
1147 }
1148 
1149 /**
1150   @brief Get 1D gradient matrix of a tensor product CeedBasis
1151 
1152   @param basis         CeedBasis
1153   @param[out] grad_1d  Variable to store gradient matrix
1154 
1155   @return An error code: 0 - success, otherwise - failure
1156 
1157   @ref Advanced
1158 **/
1159 int CeedBasisGetGrad1D(CeedBasis basis, const CeedScalar **grad_1d) {
1160   if (!basis->tensor_basis)
1161     // LCOV_EXCL_START
1162     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1163                      "CeedBasis is not a tensor product basis.");
1164   // LCOV_EXCL_STOP
1165 
1166   *grad_1d = basis->grad_1d;
1167   return CEED_ERROR_SUCCESS;
1168 }
1169 
1170 /**
1171   @brief Get divergence matrix of a CeedBasis
1172 
1173   @param basis     CeedBasis
1174   @param[out] div  Variable to store divergence matrix
1175 
1176   @return An error code: 0 - success, otherwise - failure
1177 
1178   @ref Advanced
1179 **/
1180 int CeedBasisGetDiv(CeedBasis basis, const CeedScalar **div) {
1181   if (!basis->div)
1182     // LCOV_EXCL_START
1183     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1184                      "CeedBasis does not have divergence matrix.");
1185   // LCOV_EXCL_STOP
1186 
1187   *div = basis->div;
1188   return CEED_ERROR_SUCCESS;
1189 }
1190 
1191 /**
1192   @brief Destroy a CeedBasis
1193 
1194   @param basis CeedBasis to destroy
1195 
1196   @return An error code: 0 - success, otherwise - failure
1197 
1198   @ref User
1199 **/
1200 int CeedBasisDestroy(CeedBasis *basis) {
1201   int ierr;
1202 
1203   if (!*basis || --(*basis)->ref_count > 0) return CEED_ERROR_SUCCESS;
1204   if ((*basis)->Destroy) {
1205     ierr = (*basis)->Destroy(*basis); CeedChk(ierr);
1206   }
1207   if ((*basis)->contract) {
1208     ierr = CeedTensorContractDestroy(&(*basis)->contract); CeedChk(ierr);
1209   }
1210   ierr = CeedFree(&(*basis)->interp); CeedChk(ierr);
1211   ierr = CeedFree(&(*basis)->interp_1d); CeedChk(ierr);
1212   ierr = CeedFree(&(*basis)->grad); CeedChk(ierr);
1213   ierr = CeedFree(&(*basis)->div); CeedChk(ierr);
1214   ierr = CeedFree(&(*basis)->grad_1d); CeedChk(ierr);
1215   ierr = CeedFree(&(*basis)->q_ref_1d); CeedChk(ierr);
1216   ierr = CeedFree(&(*basis)->q_weight_1d); CeedChk(ierr);
1217   ierr = CeedDestroy(&(*basis)->ceed); CeedChk(ierr);
1218   ierr = CeedFree(basis); CeedChk(ierr);
1219   return CEED_ERROR_SUCCESS;
1220 }
1221 
1222 /**
1223   @brief Construct a Gauss-Legendre quadrature
1224 
1225   @param Q                 Number of quadrature points (integrates polynomials of
1226                              degree 2*Q-1 exactly)
1227   @param[out] q_ref_1d     Array of length Q to hold the abscissa on [-1, 1]
1228   @param[out] q_weight_1d  Array of length Q to hold the weights
1229 
1230   @return An error code: 0 - success, otherwise - failure
1231 
1232   @ref Utility
1233 **/
1234 int CeedGaussQuadrature(CeedInt Q, CeedScalar *q_ref_1d,
1235                         CeedScalar *q_weight_1d) {
1236   // Allocate
1237   CeedScalar P0, P1, P2, dP2, xi, wi, PI = 4.0*atan(1.0);
1238   // Build q_ref_1d, q_weight_1d
1239   for (int i = 0; i <= Q/2; i++) {
1240     // Guess
1241     xi = cos(PI*(CeedScalar)(2*i+1)/((CeedScalar)(2*Q)));
1242     // Pn(xi)
1243     P0 = 1.0;
1244     P1 = xi;
1245     P2 = 0.0;
1246     for (int j = 2; j <= Q; j++) {
1247       P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1248       P0 = P1;
1249       P1 = P2;
1250     }
1251     // First Newton Step
1252     dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1253     xi = xi-P2/dP2;
1254     // Newton to convergence
1255     for (int k=0; k<100 && fabs(P2)>10*CEED_EPSILON; k++) {
1256       P0 = 1.0;
1257       P1 = xi;
1258       for (int j = 2; j <= Q; j++) {
1259         P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1260         P0 = P1;
1261         P1 = P2;
1262       }
1263       dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1264       xi = xi-P2/dP2;
1265     }
1266     // Save xi, wi
1267     wi = 2.0/((1.0-xi*xi)*dP2*dP2);
1268     q_weight_1d[i] = wi;
1269     q_weight_1d[Q-1-i] = wi;
1270     q_ref_1d[i] = -xi;
1271     q_ref_1d[Q-1-i]= xi;
1272   }
1273   return CEED_ERROR_SUCCESS;
1274 }
1275 
1276 /**
1277   @brief Construct a Gauss-Legendre-Lobatto quadrature
1278 
1279   @param Q                 Number of quadrature points (integrates polynomials of
1280                              degree 2*Q-3 exactly)
1281   @param[out] q_ref_1d     Array of length Q to hold the abscissa on [-1, 1]
1282   @param[out] q_weight_1d  Array of length Q to hold the weights
1283 
1284   @return An error code: 0 - success, otherwise - failure
1285 
1286   @ref Utility
1287 **/
1288 int CeedLobattoQuadrature(CeedInt Q, CeedScalar *q_ref_1d,
1289                           CeedScalar *q_weight_1d) {
1290   // Allocate
1291   CeedScalar P0, P1, P2, dP2, d2P2, xi, wi, PI = 4.0*atan(1.0);
1292   // Build q_ref_1d, q_weight_1d
1293   // Set endpoints
1294   if (Q < 2)
1295     // LCOV_EXCL_START
1296     return CeedError(NULL, CEED_ERROR_DIMENSION,
1297                      "Cannot create Lobatto quadrature with Q=%d < 2 points", Q);
1298   // LCOV_EXCL_STOP
1299   wi = 2.0/((CeedScalar)(Q*(Q-1)));
1300   if (q_weight_1d) {
1301     q_weight_1d[0] = wi;
1302     q_weight_1d[Q-1] = wi;
1303   }
1304   q_ref_1d[0] = -1.0;
1305   q_ref_1d[Q-1] = 1.0;
1306   // Interior
1307   for (int i = 1; i <= (Q-1)/2; i++) {
1308     // Guess
1309     xi = cos(PI*(CeedScalar)(i)/(CeedScalar)(Q-1));
1310     // Pn(xi)
1311     P0 = 1.0;
1312     P1 = xi;
1313     P2 = 0.0;
1314     for (int j = 2; j < Q; j++) {
1315       P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1316       P0 = P1;
1317       P1 = P2;
1318     }
1319     // First Newton step
1320     dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1321     d2P2 = (2*xi*dP2 - (CeedScalar)(Q*(Q-1))*P2)/(1.0-xi*xi);
1322     xi = xi-dP2/d2P2;
1323     // Newton to convergence
1324     for (int k=0; k<100 && fabs(dP2)>10*CEED_EPSILON; k++) {
1325       P0 = 1.0;
1326       P1 = xi;
1327       for (int j = 2; j < Q; j++) {
1328         P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1329         P0 = P1;
1330         P1 = P2;
1331       }
1332       dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1333       d2P2 = (2*xi*dP2 - (CeedScalar)(Q*(Q-1))*P2)/(1.0-xi*xi);
1334       xi = xi-dP2/d2P2;
1335     }
1336     // Save xi, wi
1337     wi = 2.0/(((CeedScalar)(Q*(Q-1)))*P2*P2);
1338     if (q_weight_1d) {
1339       q_weight_1d[i] = wi;
1340       q_weight_1d[Q-1-i] = wi;
1341     }
1342     q_ref_1d[i] = -xi;
1343     q_ref_1d[Q-1-i]= xi;
1344   }
1345   return CEED_ERROR_SUCCESS;
1346 }
1347 
1348 /**
1349   @brief Return QR Factorization of a matrix
1350 
1351   @param ceed         A Ceed context for error handling
1352   @param[in,out] mat  Row-major matrix to be factorized in place
1353   @param[in,out] tau  Vector of length m of scaling factors
1354   @param m            Number of rows
1355   @param n            Number of columns
1356 
1357   @return An error code: 0 - success, otherwise - failure
1358 
1359   @ref Utility
1360 **/
1361 int CeedQRFactorization(Ceed ceed, CeedScalar *mat, CeedScalar *tau,
1362                         CeedInt m, CeedInt n) {
1363   CeedScalar v[m];
1364 
1365   // Check m >= n
1366   if (n > m)
1367     // LCOV_EXCL_START
1368     return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
1369                      "Cannot compute QR factorization with n > m");
1370   // LCOV_EXCL_STOP
1371 
1372   for (CeedInt i=0; i<n; i++) {
1373     if (i >= m-1) { // last row of matrix, no reflection needed
1374       tau[i] = 0.;
1375       break;
1376     }
1377     // Calculate Householder vector, magnitude
1378     CeedScalar sigma = 0.0;
1379     v[i] = mat[i+n*i];
1380     for (CeedInt j=i+1; j<m; j++) {
1381       v[j] = mat[i+n*j];
1382       sigma += v[j] * v[j];
1383     }
1384     CeedScalar norm = sqrt(v[i]*v[i] + sigma); // norm of v[i:m]
1385     CeedScalar R_ii = -copysign(norm, v[i]);
1386     v[i] -= R_ii;
1387     // norm of v[i:m] after modification above and scaling below
1388     //   norm = sqrt(v[i]*v[i] + sigma) / v[i];
1389     //   tau = 2 / (norm*norm)
1390     tau[i] = 2 * v[i]*v[i] / (v[i]*v[i] + sigma);
1391     for (CeedInt j=i+1; j<m; j++)
1392       v[j] /= v[i];
1393 
1394     // Apply Householder reflector to lower right panel
1395     CeedHouseholderReflect(&mat[i*n+i+1], &v[i], tau[i], m-i, n-i-1, n, 1);
1396     // Save v
1397     mat[i+n*i] = R_ii;
1398     for (CeedInt j=i+1; j<m; j++)
1399       mat[i+n*j] = v[j];
1400   }
1401   return CEED_ERROR_SUCCESS;
1402 }
1403 
1404 /**
1405   @brief Return symmetric Schur decomposition of the symmetric matrix mat via
1406            symmetric QR factorization
1407 
1408   @param ceed         A Ceed context for error handling
1409   @param[in,out] mat  Row-major matrix to be factorized in place
1410   @param[out] lambda  Vector of length n of eigenvalues
1411   @param n            Number of rows/columns
1412 
1413   @return An error code: 0 - success, otherwise - failure
1414 
1415   @ref Utility
1416 **/
1417 CeedPragmaOptimizeOff
1418 int CeedSymmetricSchurDecomposition(Ceed ceed, CeedScalar *mat,
1419                                     CeedScalar *lambda, CeedInt n) {
1420   // Check bounds for clang-tidy
1421   if (n<2)
1422     // LCOV_EXCL_START
1423     return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
1424                      "Cannot compute symmetric Schur decomposition of scalars");
1425   // LCOV_EXCL_STOP
1426 
1427   CeedScalar v[n-1], tau[n-1], mat_T[n*n];
1428 
1429   // Copy mat to mat_T and set mat to I
1430   memcpy(mat_T, mat, n*n*sizeof(mat[0]));
1431   for (CeedInt i=0; i<n; i++)
1432     for (CeedInt j=0; j<n; j++)
1433       mat[j+n*i] = (i==j) ? 1 : 0;
1434 
1435   // Reduce to tridiagonal
1436   for (CeedInt i=0; i<n-1; i++) {
1437     // Calculate Householder vector, magnitude
1438     CeedScalar sigma = 0.0;
1439     v[i] = mat_T[i+n*(i+1)];
1440     for (CeedInt j=i+1; j<n-1; j++) {
1441       v[j] = mat_T[i+n*(j+1)];
1442       sigma += v[j] * v[j];
1443     }
1444     CeedScalar norm = sqrt(v[i]*v[i] + sigma); // norm of v[i:n-1]
1445     CeedScalar R_ii = -copysign(norm, v[i]);
1446     v[i] -= R_ii;
1447     // norm of v[i:m] after modification above and scaling below
1448     //   norm = sqrt(v[i]*v[i] + sigma) / v[i];
1449     //   tau = 2 / (norm*norm)
1450     tau[i] = i == n - 2 ? 2 : 2 * v[i]*v[i] / (v[i]*v[i] + sigma);
1451     for (CeedInt j=i+1; j<n-1; j++)
1452       v[j] /= v[i];
1453 
1454     // Update sub and super diagonal
1455     for (CeedInt j=i+2; j<n; j++) {
1456       mat_T[i+n*j] = 0; mat_T[j+n*i] = 0;
1457     }
1458     // Apply symmetric Householder reflector to lower right panel
1459     CeedHouseholderReflect(&mat_T[(i+1)+n*(i+1)], &v[i], tau[i],
1460                            n-(i+1), n-(i+1), n, 1);
1461     CeedHouseholderReflect(&mat_T[(i+1)+n*(i+1)], &v[i], tau[i],
1462                            n-(i+1), n-(i+1), 1, n);
1463 
1464     // Save v
1465     mat_T[i+n*(i+1)] = R_ii;
1466     mat_T[(i+1)+n*i] = R_ii;
1467     for (CeedInt j=i+1; j<n-1; j++) {
1468       mat_T[i+n*(j+1)] = v[j];
1469     }
1470   }
1471   // Backwards accumulation of Q
1472   for (CeedInt i=n-2; i>=0; i--) {
1473     if (tau[i] > 0.0) {
1474       v[i] = 1;
1475       for (CeedInt j=i+1; j<n-1; j++) {
1476         v[j] = mat_T[i+n*(j+1)];
1477         mat_T[i+n*(j+1)] = 0;
1478       }
1479       CeedHouseholderReflect(&mat[(i+1)+n*(i+1)], &v[i], tau[i],
1480                              n-(i+1), n-(i+1), n, 1);
1481     }
1482   }
1483 
1484   // Reduce sub and super diagonal
1485   CeedInt p = 0, q = 0, itr = 0, max_itr = n*n*n*n;
1486   CeedScalar tol = CEED_EPSILON;
1487 
1488   while (itr < max_itr) {
1489     // Update p, q, size of reduced portions of diagonal
1490     p = 0; q = 0;
1491     for (CeedInt i=n-2; i>=0; i--) {
1492       if (fabs(mat_T[i+n*(i+1)]) < tol)
1493         q += 1;
1494       else
1495         break;
1496     }
1497     for (CeedInt i=0; i<n-q-1; i++) {
1498       if (fabs(mat_T[i+n*(i+1)]) < tol)
1499         p += 1;
1500       else
1501         break;
1502     }
1503     if (q == n-1) break; // Finished reducing
1504 
1505     // Reduce tridiagonal portion
1506     CeedScalar t_nn = mat_T[(n-1-q)+n*(n-1-q)],
1507                t_nnm1 = mat_T[(n-2-q)+n*(n-1-q)];
1508     CeedScalar d = (mat_T[(n-2-q)+n*(n-2-q)] - t_nn)/2;
1509     CeedScalar mu = t_nn - t_nnm1*t_nnm1 /
1510                     (d + copysign(sqrt(d*d + t_nnm1*t_nnm1), d));
1511     CeedScalar x = mat_T[p+n*p] - mu;
1512     CeedScalar z = mat_T[p+n*(p+1)];
1513     for (CeedInt k=p; k<n-q-1; k++) {
1514       // Compute Givens rotation
1515       CeedScalar c = 1, s = 0;
1516       if (fabs(z) > tol) {
1517         if (fabs(z) > fabs(x)) {
1518           CeedScalar tau = -x/z;
1519           s = 1/sqrt(1+tau*tau), c = s*tau;
1520         } else {
1521           CeedScalar tau = -z/x;
1522           c = 1/sqrt(1+tau*tau), s = c*tau;
1523         }
1524       }
1525 
1526       // Apply Givens rotation to T
1527       CeedGivensRotation(mat_T, c, s, CEED_NOTRANSPOSE, k, k+1, n, n);
1528       CeedGivensRotation(mat_T, c, s, CEED_TRANSPOSE, k, k+1, n, n);
1529 
1530       // Apply Givens rotation to Q
1531       CeedGivensRotation(mat, c, s, CEED_NOTRANSPOSE, k, k+1, n, n);
1532 
1533       // Update x, z
1534       if (k < n-q-2) {
1535         x = mat_T[k+n*(k+1)];
1536         z = mat_T[k+n*(k+2)];
1537       }
1538     }
1539     itr++;
1540   }
1541 
1542   // Save eigenvalues
1543   for (CeedInt i=0; i<n; i++)
1544     lambda[i] = mat_T[i+n*i];
1545 
1546   // Check convergence
1547   if (itr == max_itr && q < n-1)
1548     // LCOV_EXCL_START
1549     return CeedError(ceed, CEED_ERROR_MINOR,
1550                      "Symmetric QR failed to converge");
1551   // LCOV_EXCL_STOP
1552   return CEED_ERROR_SUCCESS;
1553 }
1554 CeedPragmaOptimizeOn
1555 
1556 /**
1557   @brief Return Simultaneous Diagonalization of two matrices. This solves the
1558            generalized eigenvalue problem A x = lambda B x, where A and B
1559            are symmetric and B is positive definite. We generate the matrix X
1560            and vector Lambda such that X^T A X = Lambda and X^T B X = I. This
1561            is equivalent to the LAPACK routine 'sygv' with TYPE = 1.
1562 
1563   @param ceed         A Ceed context for error handling
1564   @param[in] mat_A    Row-major matrix to be factorized with eigenvalues
1565   @param[in] mat_B    Row-major matrix to be factorized to identity
1566   @param[out] mat_X   Row-major orthogonal matrix
1567   @param[out] lambda  Vector of length n of generalized eigenvalues
1568   @param n            Number of rows/columns
1569 
1570   @return An error code: 0 - success, otherwise - failure
1571 
1572   @ref Utility
1573 **/
1574 CeedPragmaOptimizeOff
1575 int CeedSimultaneousDiagonalization(Ceed ceed, CeedScalar *mat_A,
1576                                     CeedScalar *mat_B, CeedScalar *mat_X,
1577                                     CeedScalar *lambda, CeedInt n) {
1578   int ierr;
1579   CeedScalar *mat_C, *mat_G, *vec_D;
1580   ierr = CeedCalloc(n*n, &mat_C); CeedChk(ierr);
1581   ierr = CeedCalloc(n*n, &mat_G); CeedChk(ierr);
1582   ierr = CeedCalloc(n, &vec_D); CeedChk(ierr);
1583 
1584   // Compute B = G D G^T
1585   memcpy(mat_G, mat_B, n*n*sizeof(mat_B[0]));
1586   ierr = CeedSymmetricSchurDecomposition(ceed, mat_G, vec_D, n); CeedChk(ierr);
1587 
1588   // Sort eigenvalues
1589   for (CeedInt i=n-1; i>=0; i--)
1590     for (CeedInt j=0; j<i; j++) {
1591       if (fabs(vec_D[j]) > fabs(vec_D[j+1])) {
1592         CeedScalar temp;
1593         temp = vec_D[j]; vec_D[j] = vec_D[j+1]; vec_D[j+1] = temp;
1594         for (CeedInt k=0; k<n; k++) {
1595           temp = mat_G[k*n+j]; mat_G[k*n+j] = mat_G[k*n+j+1]; mat_G[k*n+j+1] = temp;
1596         }
1597       }
1598     }
1599 
1600   // Compute C = (G D^1/2)^-1 A (G D^1/2)^-T
1601   //           = D^-1/2 G^T A G D^-1/2
1602   // -- D = D^-1/2
1603   for (CeedInt i=0; i<n; i++)
1604     vec_D[i] = 1./sqrt(vec_D[i]);
1605   // -- G = G D^-1/2
1606   // -- C = D^-1/2 G^T
1607   for (CeedInt i=0; i<n; i++)
1608     for (CeedInt j=0; j<n; j++) {
1609       mat_G[i*n+j] *= vec_D[j];
1610       mat_C[j*n+i]  = mat_G[i*n+j];
1611     }
1612   // -- X = (D^-1/2 G^T) A
1613   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_C,
1614                             (const CeedScalar *)mat_A, mat_X, n, n, n);
1615   CeedChk(ierr);
1616   // -- C = (D^-1/2 G^T A) (G D^-1/2)
1617   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_X,
1618                             (const CeedScalar *)mat_G, mat_C, n, n, n);
1619   CeedChk(ierr);
1620 
1621   // Compute Q^T C Q = lambda
1622   ierr = CeedSymmetricSchurDecomposition(ceed, mat_C, lambda, n); CeedChk(ierr);
1623 
1624   // Sort eigenvalues
1625   for (CeedInt i=n-1; i>=0; i--)
1626     for (CeedInt j=0; j<i; j++) {
1627       if (fabs(lambda[j]) > fabs(lambda[j+1])) {
1628         CeedScalar temp;
1629         temp = lambda[j]; lambda[j] = lambda[j+1]; lambda[j+1] = temp;
1630         for (CeedInt k=0; k<n; k++) {
1631           temp = mat_C[k*n+j]; mat_C[k*n+j] = mat_C[k*n+j+1]; mat_C[k*n+j+1] = temp;
1632         }
1633       }
1634     }
1635 
1636   // Set X = (G D^1/2)^-T Q
1637   //       = G D^-1/2 Q
1638   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_G,
1639                             (const CeedScalar *)mat_C, mat_X, n, n, n);
1640   CeedChk(ierr);
1641 
1642   // Cleanup
1643   ierr = CeedFree(&mat_C); CeedChk(ierr);
1644   ierr = CeedFree(&mat_G); CeedChk(ierr);
1645   ierr = CeedFree(&vec_D); CeedChk(ierr);
1646   return CEED_ERROR_SUCCESS;
1647 }
1648 CeedPragmaOptimizeOn
1649 
1650 /// @}
1651