xref: /libCEED/interface/ceed-basis.c (revision e79b91d9f61753a734e6e21c778d772fcdbcc265)
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   CeedSize u_length = 0, v_length;
806   CeedInt dim, num_comp, num_nodes, num_qpts;
807   ierr = CeedBasisGetDimension(basis, &dim); CeedChk(ierr);
808   ierr = CeedBasisGetNumComponents(basis, &num_comp); CeedChk(ierr);
809   ierr = CeedBasisGetNumNodes(basis, &num_nodes); CeedChk(ierr);
810   ierr = CeedBasisGetNumQuadraturePoints(basis, &num_qpts); CeedChk(ierr);
811   ierr = CeedVectorGetLength(v, &v_length); CeedChk(ierr);
812   if (u) {
813     ierr = CeedVectorGetLength(u, &u_length); CeedChk(ierr);
814   }
815 
816   if (!basis->Apply)
817     // LCOV_EXCL_START
818     return CeedError(basis->ceed, CEED_ERROR_UNSUPPORTED,
819                      "Backend does not support BasisApply");
820   // LCOV_EXCL_STOP
821 
822   // Check compatibility of topological and geometrical dimensions
823   if ((t_mode == CEED_TRANSPOSE && (v_length%num_nodes != 0 ||
824                                     u_length%num_qpts != 0)) ||
825       (t_mode == CEED_NOTRANSPOSE && (u_length%num_nodes != 0 ||
826                                       v_length%num_qpts != 0)))
827     // LCOV_EXCL_START
828     return CeedError(basis->ceed, CEED_ERROR_DIMENSION,
829                      "Length of input/output vectors "
830                      "incompatible with basis dimensions");
831   // LCOV_EXCL_STOP
832 
833   // Check vector lengths to prevent out of bounds issues
834   bool bad_dims = false;
835   switch (eval_mode) {
836   case CEED_EVAL_NONE:
837   case CEED_EVAL_INTERP: bad_dims =
838       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
839                                      v_length < num_elem*num_comp*num_nodes)) ||
840        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
841                                        u_length < num_elem*num_comp*num_nodes)));
842     break;
843   case CEED_EVAL_GRAD: bad_dims =
844       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts*dim ||
845                                      v_length < num_elem*num_comp*num_nodes)) ||
846        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp*dim ||
847                                        u_length < num_elem*num_comp*num_nodes)));
848     break;
849   case CEED_EVAL_WEIGHT:
850     bad_dims = v_length < num_elem*num_qpts;
851     break;
852   // LCOV_EXCL_START
853   case CEED_EVAL_DIV: bad_dims =
854       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
855                                      v_length < num_elem*num_comp*num_nodes)) ||
856        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
857                                        u_length < num_elem*num_comp*num_nodes)));
858     break;
859   case CEED_EVAL_CURL: bad_dims =
860       ((t_mode == CEED_TRANSPOSE && (u_length < num_elem*num_comp*num_qpts ||
861                                      v_length < num_elem*num_comp*num_nodes)) ||
862        (t_mode == CEED_NOTRANSPOSE && (v_length < num_elem*num_qpts*num_comp ||
863                                        u_length < num_elem*num_comp*num_nodes)));
864     break;
865     // LCOV_EXCL_STOP
866   }
867   if (bad_dims)
868     // LCOV_EXCL_START
869     return CeedError(basis->ceed, CEED_ERROR_DIMENSION,
870                      "Input/output vectors too short for basis and evaluation mode");
871   // LCOV_EXCL_STOP
872 
873   ierr = basis->Apply(basis, num_elem, t_mode, eval_mode, u, v); CeedChk(ierr);
874   return CEED_ERROR_SUCCESS;
875 }
876 
877 /**
878   @brief Get Ceed associated with a CeedBasis
879 
880   @param basis      CeedBasis
881   @param[out] ceed  Variable to store Ceed
882 
883   @return An error code: 0 - success, otherwise - failure
884 
885   @ref Advanced
886 **/
887 int CeedBasisGetCeed(CeedBasis basis, Ceed *ceed) {
888   *ceed = basis->ceed;
889   return CEED_ERROR_SUCCESS;
890 }
891 
892 /**
893   @brief Get dimension for given CeedBasis
894 
895   @param basis     CeedBasis
896   @param[out] dim  Variable to store dimension of basis
897 
898   @return An error code: 0 - success, otherwise - failure
899 
900   @ref Advanced
901 **/
902 int CeedBasisGetDimension(CeedBasis basis, CeedInt *dim) {
903   *dim = basis->dim;
904   return CEED_ERROR_SUCCESS;
905 }
906 
907 /**
908   @brief Get topology for given CeedBasis
909 
910   @param basis      CeedBasis
911   @param[out] topo  Variable to store topology of basis
912 
913   @return An error code: 0 - success, otherwise - failure
914 
915   @ref Advanced
916 **/
917 int CeedBasisGetTopology(CeedBasis basis, CeedElemTopology *topo) {
918   *topo = basis->topo;
919   return CEED_ERROR_SUCCESS;
920 }
921 
922 /**
923   @brief Get number of Q-vector components for given CeedBasis
924 
925   @param basis          CeedBasis
926   @param[out] Q_comp  Variable to store number of Q-vector components of basis
927 
928   @return An error code: 0 - success, otherwise - failure
929 
930   @ref Advanced
931 **/
932 int CeedBasisGetNumQuadratureComponents(CeedBasis basis, CeedInt *Q_comp) {
933   *Q_comp = basis->Q_comp;
934   return CEED_ERROR_SUCCESS;
935 }
936 
937 /**
938   @brief Get number of components for given CeedBasis
939 
940   @param basis          CeedBasis
941   @param[out] num_comp  Variable to store number of components of basis
942 
943   @return An error code: 0 - success, otherwise - failure
944 
945   @ref Advanced
946 **/
947 int CeedBasisGetNumComponents(CeedBasis basis, CeedInt *num_comp) {
948   *num_comp = basis->num_comp;
949   return CEED_ERROR_SUCCESS;
950 }
951 
952 /**
953   @brief Get total number of nodes (in dim dimensions) of a CeedBasis
954 
955   @param basis   CeedBasis
956   @param[out] P  Variable to store number of nodes
957 
958   @return An error code: 0 - success, otherwise - failure
959 
960   @ref Utility
961 **/
962 int CeedBasisGetNumNodes(CeedBasis basis, CeedInt *P) {
963   *P = basis->P;
964   return CEED_ERROR_SUCCESS;
965 }
966 
967 /**
968   @brief Get total number of nodes (in 1 dimension) of a CeedBasis
969 
970   @param basis     CeedBasis
971   @param[out] P_1d  Variable to store number of nodes
972 
973   @return An error code: 0 - success, otherwise - failure
974 
975   @ref Advanced
976 **/
977 int CeedBasisGetNumNodes1D(CeedBasis basis, CeedInt *P_1d) {
978   if (!basis->tensor_basis)
979     // LCOV_EXCL_START
980     return CeedError(basis->ceed, CEED_ERROR_MINOR,
981                      "Cannot supply P_1d for non-tensor basis");
982   // LCOV_EXCL_STOP
983 
984   *P_1d = basis->P_1d;
985   return CEED_ERROR_SUCCESS;
986 }
987 
988 /**
989   @brief Get total number of quadrature points (in dim dimensions) of a CeedBasis
990 
991   @param basis   CeedBasis
992   @param[out] Q  Variable to store number of quadrature points
993 
994   @return An error code: 0 - success, otherwise - failure
995 
996   @ref Utility
997 **/
998 int CeedBasisGetNumQuadraturePoints(CeedBasis basis, CeedInt *Q) {
999   *Q = basis->Q;
1000   return CEED_ERROR_SUCCESS;
1001 }
1002 
1003 /**
1004   @brief Get total number of quadrature points (in 1 dimension) of a CeedBasis
1005 
1006   @param basis      CeedBasis
1007   @param[out] Q_1d  Variable to store number of quadrature points
1008 
1009   @return An error code: 0 - success, otherwise - failure
1010 
1011   @ref Advanced
1012 **/
1013 int CeedBasisGetNumQuadraturePoints1D(CeedBasis basis, CeedInt *Q_1d) {
1014   if (!basis->tensor_basis)
1015     // LCOV_EXCL_START
1016     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1017                      "Cannot supply Q_1d for non-tensor basis");
1018   // LCOV_EXCL_STOP
1019 
1020   *Q_1d = basis->Q_1d;
1021   return CEED_ERROR_SUCCESS;
1022 }
1023 
1024 /**
1025   @brief Get reference coordinates of quadrature points (in dim dimensions)
1026          of a CeedBasis
1027 
1028   @param basis       CeedBasis
1029   @param[out] q_ref  Variable to store reference coordinates of quadrature points
1030 
1031   @return An error code: 0 - success, otherwise - failure
1032 
1033   @ref Advanced
1034 **/
1035 int CeedBasisGetQRef(CeedBasis basis, const CeedScalar **q_ref) {
1036   *q_ref = basis->q_ref_1d;
1037   return CEED_ERROR_SUCCESS;
1038 }
1039 
1040 /**
1041   @brief Get quadrature weights of quadrature points (in dim dimensions)
1042          of a CeedBasis
1043 
1044   @param basis          CeedBasis
1045   @param[out] q_weight  Variable to store quadrature weights
1046 
1047   @return An error code: 0 - success, otherwise - failure
1048 
1049   @ref Advanced
1050 **/
1051 int CeedBasisGetQWeights(CeedBasis basis, const CeedScalar **q_weight) {
1052   *q_weight = basis->q_weight_1d;
1053   return CEED_ERROR_SUCCESS;
1054 }
1055 
1056 /**
1057   @brief Get interpolation matrix of a CeedBasis
1058 
1059   @param basis        CeedBasis
1060   @param[out] interp  Variable to store interpolation matrix
1061 
1062   @return An error code: 0 - success, otherwise - failure
1063 
1064   @ref Advanced
1065 **/
1066 int CeedBasisGetInterp(CeedBasis basis, const CeedScalar **interp) {
1067   if (!basis->interp && basis->tensor_basis) {
1068     // Allocate
1069     int ierr;
1070     ierr = CeedMalloc(basis->Q*basis->P, &basis->interp); CeedChk(ierr);
1071 
1072     // Initialize
1073     for (CeedInt i=0; i<basis->Q*basis->P; i++)
1074       basis->interp[i] = 1.0;
1075 
1076     // Calculate
1077     for (CeedInt d=0; d<basis->dim; d++)
1078       for (CeedInt qpt=0; qpt<basis->Q; qpt++)
1079         for (CeedInt node=0; node<basis->P; node++) {
1080           CeedInt p = (node / CeedIntPow(basis->P_1d, d)) % basis->P_1d;
1081           CeedInt q = (qpt / CeedIntPow(basis->Q_1d, d)) % basis->Q_1d;
1082           basis->interp[qpt*(basis->P)+node] *= basis->interp_1d[q*basis->P_1d+p];
1083         }
1084   }
1085   *interp = basis->interp;
1086   return CEED_ERROR_SUCCESS;
1087 }
1088 
1089 /**
1090   @brief Get 1D interpolation matrix of a tensor product CeedBasis
1091 
1092   @param basis           CeedBasis
1093   @param[out] interp_1d  Variable to store interpolation matrix
1094 
1095   @return An error code: 0 - success, otherwise - failure
1096 
1097   @ref Backend
1098 **/
1099 int CeedBasisGetInterp1D(CeedBasis basis, const CeedScalar **interp_1d) {
1100   if (!basis->tensor_basis)
1101     // LCOV_EXCL_START
1102     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1103                      "CeedBasis is not a tensor product basis.");
1104   // LCOV_EXCL_STOP
1105 
1106   *interp_1d = basis->interp_1d;
1107   return CEED_ERROR_SUCCESS;
1108 }
1109 
1110 /**
1111   @brief Get gradient matrix of a CeedBasis
1112 
1113   @param basis      CeedBasis
1114   @param[out] grad  Variable to store gradient matrix
1115 
1116   @return An error code: 0 - success, otherwise - failure
1117 
1118   @ref Advanced
1119 **/
1120 int CeedBasisGetGrad(CeedBasis basis, const CeedScalar **grad) {
1121   if (!basis->grad && basis->tensor_basis) {
1122     // Allocate
1123     int ierr;
1124     ierr = CeedMalloc(basis->dim*basis->Q*basis->P, &basis->grad);
1125     CeedChk(ierr);
1126 
1127     // Initialize
1128     for (CeedInt i=0; i<basis->dim*basis->Q*basis->P; i++)
1129       basis->grad[i] = 1.0;
1130 
1131     // Calculate
1132     for (CeedInt d=0; d<basis->dim; d++)
1133       for (CeedInt i=0; i<basis->dim; i++)
1134         for (CeedInt qpt=0; qpt<basis->Q; qpt++)
1135           for (CeedInt node=0; node<basis->P; node++) {
1136             CeedInt p = (node / CeedIntPow(basis->P_1d, d)) % basis->P_1d;
1137             CeedInt q = (qpt / CeedIntPow(basis->Q_1d, d)) % basis->Q_1d;
1138             if (i == d)
1139               basis->grad[(i*basis->Q+qpt)*(basis->P)+node] *=
1140                 basis->grad_1d[q*basis->P_1d+p];
1141             else
1142               basis->grad[(i*basis->Q+qpt)*(basis->P)+node] *=
1143                 basis->interp_1d[q*basis->P_1d+p];
1144           }
1145   }
1146   *grad = basis->grad;
1147   return CEED_ERROR_SUCCESS;
1148 }
1149 
1150 /**
1151   @brief Get 1D gradient matrix of a tensor product CeedBasis
1152 
1153   @param basis         CeedBasis
1154   @param[out] grad_1d  Variable to store gradient matrix
1155 
1156   @return An error code: 0 - success, otherwise - failure
1157 
1158   @ref Advanced
1159 **/
1160 int CeedBasisGetGrad1D(CeedBasis basis, const CeedScalar **grad_1d) {
1161   if (!basis->tensor_basis)
1162     // LCOV_EXCL_START
1163     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1164                      "CeedBasis is not a tensor product basis.");
1165   // LCOV_EXCL_STOP
1166 
1167   *grad_1d = basis->grad_1d;
1168   return CEED_ERROR_SUCCESS;
1169 }
1170 
1171 /**
1172   @brief Get divergence matrix of a CeedBasis
1173 
1174   @param basis     CeedBasis
1175   @param[out] div  Variable to store divergence matrix
1176 
1177   @return An error code: 0 - success, otherwise - failure
1178 
1179   @ref Advanced
1180 **/
1181 int CeedBasisGetDiv(CeedBasis basis, const CeedScalar **div) {
1182   if (!basis->div)
1183     // LCOV_EXCL_START
1184     return CeedError(basis->ceed, CEED_ERROR_MINOR,
1185                      "CeedBasis does not have divergence matrix.");
1186   // LCOV_EXCL_STOP
1187 
1188   *div = basis->div;
1189   return CEED_ERROR_SUCCESS;
1190 }
1191 
1192 /**
1193   @brief Destroy a CeedBasis
1194 
1195   @param basis CeedBasis to destroy
1196 
1197   @return An error code: 0 - success, otherwise - failure
1198 
1199   @ref User
1200 **/
1201 int CeedBasisDestroy(CeedBasis *basis) {
1202   int ierr;
1203 
1204   if (!*basis || --(*basis)->ref_count > 0) return CEED_ERROR_SUCCESS;
1205   if ((*basis)->Destroy) {
1206     ierr = (*basis)->Destroy(*basis); CeedChk(ierr);
1207   }
1208   if ((*basis)->contract) {
1209     ierr = CeedTensorContractDestroy(&(*basis)->contract); CeedChk(ierr);
1210   }
1211   ierr = CeedFree(&(*basis)->interp); CeedChk(ierr);
1212   ierr = CeedFree(&(*basis)->interp_1d); CeedChk(ierr);
1213   ierr = CeedFree(&(*basis)->grad); CeedChk(ierr);
1214   ierr = CeedFree(&(*basis)->div); CeedChk(ierr);
1215   ierr = CeedFree(&(*basis)->grad_1d); CeedChk(ierr);
1216   ierr = CeedFree(&(*basis)->q_ref_1d); CeedChk(ierr);
1217   ierr = CeedFree(&(*basis)->q_weight_1d); CeedChk(ierr);
1218   ierr = CeedDestroy(&(*basis)->ceed); CeedChk(ierr);
1219   ierr = CeedFree(basis); CeedChk(ierr);
1220   return CEED_ERROR_SUCCESS;
1221 }
1222 
1223 /**
1224   @brief Construct a Gauss-Legendre quadrature
1225 
1226   @param Q                 Number of quadrature points (integrates polynomials of
1227                              degree 2*Q-1 exactly)
1228   @param[out] q_ref_1d     Array of length Q to hold the abscissa on [-1, 1]
1229   @param[out] q_weight_1d  Array of length Q to hold the weights
1230 
1231   @return An error code: 0 - success, otherwise - failure
1232 
1233   @ref Utility
1234 **/
1235 int CeedGaussQuadrature(CeedInt Q, CeedScalar *q_ref_1d,
1236                         CeedScalar *q_weight_1d) {
1237   // Allocate
1238   CeedScalar P0, P1, P2, dP2, xi, wi, PI = 4.0*atan(1.0);
1239   // Build q_ref_1d, q_weight_1d
1240   for (int i = 0; i <= Q/2; i++) {
1241     // Guess
1242     xi = cos(PI*(CeedScalar)(2*i+1)/((CeedScalar)(2*Q)));
1243     // Pn(xi)
1244     P0 = 1.0;
1245     P1 = xi;
1246     P2 = 0.0;
1247     for (int j = 2; j <= Q; j++) {
1248       P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1249       P0 = P1;
1250       P1 = P2;
1251     }
1252     // First Newton Step
1253     dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1254     xi = xi-P2/dP2;
1255     // Newton to convergence
1256     for (int k=0; k<100 && fabs(P2)>10*CEED_EPSILON; k++) {
1257       P0 = 1.0;
1258       P1 = xi;
1259       for (int j = 2; j <= Q; j++) {
1260         P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1261         P0 = P1;
1262         P1 = P2;
1263       }
1264       dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1265       xi = xi-P2/dP2;
1266     }
1267     // Save xi, wi
1268     wi = 2.0/((1.0-xi*xi)*dP2*dP2);
1269     q_weight_1d[i] = wi;
1270     q_weight_1d[Q-1-i] = wi;
1271     q_ref_1d[i] = -xi;
1272     q_ref_1d[Q-1-i]= xi;
1273   }
1274   return CEED_ERROR_SUCCESS;
1275 }
1276 
1277 /**
1278   @brief Construct a Gauss-Legendre-Lobatto quadrature
1279 
1280   @param Q                 Number of quadrature points (integrates polynomials of
1281                              degree 2*Q-3 exactly)
1282   @param[out] q_ref_1d     Array of length Q to hold the abscissa on [-1, 1]
1283   @param[out] q_weight_1d  Array of length Q to hold the weights
1284 
1285   @return An error code: 0 - success, otherwise - failure
1286 
1287   @ref Utility
1288 **/
1289 int CeedLobattoQuadrature(CeedInt Q, CeedScalar *q_ref_1d,
1290                           CeedScalar *q_weight_1d) {
1291   // Allocate
1292   CeedScalar P0, P1, P2, dP2, d2P2, xi, wi, PI = 4.0*atan(1.0);
1293   // Build q_ref_1d, q_weight_1d
1294   // Set endpoints
1295   if (Q < 2)
1296     // LCOV_EXCL_START
1297     return CeedError(NULL, CEED_ERROR_DIMENSION,
1298                      "Cannot create Lobatto quadrature with Q=%d < 2 points", Q);
1299   // LCOV_EXCL_STOP
1300   wi = 2.0/((CeedScalar)(Q*(Q-1)));
1301   if (q_weight_1d) {
1302     q_weight_1d[0] = wi;
1303     q_weight_1d[Q-1] = wi;
1304   }
1305   q_ref_1d[0] = -1.0;
1306   q_ref_1d[Q-1] = 1.0;
1307   // Interior
1308   for (int i = 1; i <= (Q-1)/2; i++) {
1309     // Guess
1310     xi = cos(PI*(CeedScalar)(i)/(CeedScalar)(Q-1));
1311     // Pn(xi)
1312     P0 = 1.0;
1313     P1 = xi;
1314     P2 = 0.0;
1315     for (int j = 2; j < Q; j++) {
1316       P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1317       P0 = P1;
1318       P1 = P2;
1319     }
1320     // First Newton step
1321     dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1322     d2P2 = (2*xi*dP2 - (CeedScalar)(Q*(Q-1))*P2)/(1.0-xi*xi);
1323     xi = xi-dP2/d2P2;
1324     // Newton to convergence
1325     for (int k=0; k<100 && fabs(dP2)>10*CEED_EPSILON; k++) {
1326       P0 = 1.0;
1327       P1 = xi;
1328       for (int j = 2; j < Q; j++) {
1329         P2 = (((CeedScalar)(2*j-1))*xi*P1-((CeedScalar)(j-1))*P0)/((CeedScalar)(j));
1330         P0 = P1;
1331         P1 = P2;
1332       }
1333       dP2 = (xi*P2 - P0)*(CeedScalar)Q/(xi*xi-1.0);
1334       d2P2 = (2*xi*dP2 - (CeedScalar)(Q*(Q-1))*P2)/(1.0-xi*xi);
1335       xi = xi-dP2/d2P2;
1336     }
1337     // Save xi, wi
1338     wi = 2.0/(((CeedScalar)(Q*(Q-1)))*P2*P2);
1339     if (q_weight_1d) {
1340       q_weight_1d[i] = wi;
1341       q_weight_1d[Q-1-i] = wi;
1342     }
1343     q_ref_1d[i] = -xi;
1344     q_ref_1d[Q-1-i]= xi;
1345   }
1346   return CEED_ERROR_SUCCESS;
1347 }
1348 
1349 /**
1350   @brief Return QR Factorization of a matrix
1351 
1352   @param ceed         A Ceed context for error handling
1353   @param[in,out] mat  Row-major matrix to be factorized in place
1354   @param[in,out] tau  Vector of length m of scaling factors
1355   @param m            Number of rows
1356   @param n            Number of columns
1357 
1358   @return An error code: 0 - success, otherwise - failure
1359 
1360   @ref Utility
1361 **/
1362 int CeedQRFactorization(Ceed ceed, CeedScalar *mat, CeedScalar *tau,
1363                         CeedInt m, CeedInt n) {
1364   CeedScalar v[m];
1365 
1366   // Check m >= n
1367   if (n > m)
1368     // LCOV_EXCL_START
1369     return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
1370                      "Cannot compute QR factorization with n > m");
1371   // LCOV_EXCL_STOP
1372 
1373   for (CeedInt i=0; i<n; i++) {
1374     if (i >= m-1) { // last row of matrix, no reflection needed
1375       tau[i] = 0.;
1376       break;
1377     }
1378     // Calculate Householder vector, magnitude
1379     CeedScalar sigma = 0.0;
1380     v[i] = mat[i+n*i];
1381     for (CeedInt j=i+1; j<m; j++) {
1382       v[j] = mat[i+n*j];
1383       sigma += v[j] * v[j];
1384     }
1385     CeedScalar norm = sqrt(v[i]*v[i] + sigma); // norm of v[i:m]
1386     CeedScalar R_ii = -copysign(norm, v[i]);
1387     v[i] -= R_ii;
1388     // norm of v[i:m] after modification above and scaling below
1389     //   norm = sqrt(v[i]*v[i] + sigma) / v[i];
1390     //   tau = 2 / (norm*norm)
1391     tau[i] = 2 * v[i]*v[i] / (v[i]*v[i] + sigma);
1392     for (CeedInt j=i+1; j<m; j++)
1393       v[j] /= v[i];
1394 
1395     // Apply Householder reflector to lower right panel
1396     CeedHouseholderReflect(&mat[i*n+i+1], &v[i], tau[i], m-i, n-i-1, n, 1);
1397     // Save v
1398     mat[i+n*i] = R_ii;
1399     for (CeedInt j=i+1; j<m; j++)
1400       mat[i+n*j] = v[j];
1401   }
1402   return CEED_ERROR_SUCCESS;
1403 }
1404 
1405 /**
1406   @brief Return symmetric Schur decomposition of the symmetric matrix mat via
1407            symmetric QR factorization
1408 
1409   @param ceed         A Ceed context for error handling
1410   @param[in,out] mat  Row-major matrix to be factorized in place
1411   @param[out] lambda  Vector of length n of eigenvalues
1412   @param n            Number of rows/columns
1413 
1414   @return An error code: 0 - success, otherwise - failure
1415 
1416   @ref Utility
1417 **/
1418 CeedPragmaOptimizeOff
1419 int CeedSymmetricSchurDecomposition(Ceed ceed, CeedScalar *mat,
1420                                     CeedScalar *lambda, CeedInt n) {
1421   // Check bounds for clang-tidy
1422   if (n<2)
1423     // LCOV_EXCL_START
1424     return CeedError(ceed, CEED_ERROR_UNSUPPORTED,
1425                      "Cannot compute symmetric Schur decomposition of scalars");
1426   // LCOV_EXCL_STOP
1427 
1428   CeedScalar v[n-1], tau[n-1], mat_T[n*n];
1429 
1430   // Copy mat to mat_T and set mat to I
1431   memcpy(mat_T, mat, n*n*sizeof(mat[0]));
1432   for (CeedInt i=0; i<n; i++)
1433     for (CeedInt j=0; j<n; j++)
1434       mat[j+n*i] = (i==j) ? 1 : 0;
1435 
1436   // Reduce to tridiagonal
1437   for (CeedInt i=0; i<n-1; i++) {
1438     // Calculate Householder vector, magnitude
1439     CeedScalar sigma = 0.0;
1440     v[i] = mat_T[i+n*(i+1)];
1441     for (CeedInt j=i+1; j<n-1; j++) {
1442       v[j] = mat_T[i+n*(j+1)];
1443       sigma += v[j] * v[j];
1444     }
1445     CeedScalar norm = sqrt(v[i]*v[i] + sigma); // norm of v[i:n-1]
1446     CeedScalar R_ii = -copysign(norm, v[i]);
1447     v[i] -= R_ii;
1448     // norm of v[i:m] after modification above and scaling below
1449     //   norm = sqrt(v[i]*v[i] + sigma) / v[i];
1450     //   tau = 2 / (norm*norm)
1451     tau[i] = i == n - 2 ? 2 : 2 * v[i]*v[i] / (v[i]*v[i] + sigma);
1452     for (CeedInt j=i+1; j<n-1; j++)
1453       v[j] /= v[i];
1454 
1455     // Update sub and super diagonal
1456     for (CeedInt j=i+2; j<n; j++) {
1457       mat_T[i+n*j] = 0; mat_T[j+n*i] = 0;
1458     }
1459     // Apply symmetric Householder reflector to lower right panel
1460     CeedHouseholderReflect(&mat_T[(i+1)+n*(i+1)], &v[i], tau[i],
1461                            n-(i+1), n-(i+1), n, 1);
1462     CeedHouseholderReflect(&mat_T[(i+1)+n*(i+1)], &v[i], tau[i],
1463                            n-(i+1), n-(i+1), 1, n);
1464 
1465     // Save v
1466     mat_T[i+n*(i+1)] = R_ii;
1467     mat_T[(i+1)+n*i] = R_ii;
1468     for (CeedInt j=i+1; j<n-1; j++) {
1469       mat_T[i+n*(j+1)] = v[j];
1470     }
1471   }
1472   // Backwards accumulation of Q
1473   for (CeedInt i=n-2; i>=0; i--) {
1474     if (tau[i] > 0.0) {
1475       v[i] = 1;
1476       for (CeedInt j=i+1; j<n-1; j++) {
1477         v[j] = mat_T[i+n*(j+1)];
1478         mat_T[i+n*(j+1)] = 0;
1479       }
1480       CeedHouseholderReflect(&mat[(i+1)+n*(i+1)], &v[i], tau[i],
1481                              n-(i+1), n-(i+1), n, 1);
1482     }
1483   }
1484 
1485   // Reduce sub and super diagonal
1486   CeedInt p = 0, q = 0, itr = 0, max_itr = n*n*n*n;
1487   CeedScalar tol = CEED_EPSILON;
1488 
1489   while (itr < max_itr) {
1490     // Update p, q, size of reduced portions of diagonal
1491     p = 0; q = 0;
1492     for (CeedInt i=n-2; i>=0; i--) {
1493       if (fabs(mat_T[i+n*(i+1)]) < tol)
1494         q += 1;
1495       else
1496         break;
1497     }
1498     for (CeedInt i=0; i<n-q-1; i++) {
1499       if (fabs(mat_T[i+n*(i+1)]) < tol)
1500         p += 1;
1501       else
1502         break;
1503     }
1504     if (q == n-1) break; // Finished reducing
1505 
1506     // Reduce tridiagonal portion
1507     CeedScalar t_nn = mat_T[(n-1-q)+n*(n-1-q)],
1508                t_nnm1 = mat_T[(n-2-q)+n*(n-1-q)];
1509     CeedScalar d = (mat_T[(n-2-q)+n*(n-2-q)] - t_nn)/2;
1510     CeedScalar mu = t_nn - t_nnm1*t_nnm1 /
1511                     (d + copysign(sqrt(d*d + t_nnm1*t_nnm1), d));
1512     CeedScalar x = mat_T[p+n*p] - mu;
1513     CeedScalar z = mat_T[p+n*(p+1)];
1514     for (CeedInt k=p; k<n-q-1; k++) {
1515       // Compute Givens rotation
1516       CeedScalar c = 1, s = 0;
1517       if (fabs(z) > tol) {
1518         if (fabs(z) > fabs(x)) {
1519           CeedScalar tau = -x/z;
1520           s = 1/sqrt(1+tau*tau), c = s*tau;
1521         } else {
1522           CeedScalar tau = -z/x;
1523           c = 1/sqrt(1+tau*tau), s = c*tau;
1524         }
1525       }
1526 
1527       // Apply Givens rotation to T
1528       CeedGivensRotation(mat_T, c, s, CEED_NOTRANSPOSE, k, k+1, n, n);
1529       CeedGivensRotation(mat_T, c, s, CEED_TRANSPOSE, k, k+1, n, n);
1530 
1531       // Apply Givens rotation to Q
1532       CeedGivensRotation(mat, c, s, CEED_NOTRANSPOSE, k, k+1, n, n);
1533 
1534       // Update x, z
1535       if (k < n-q-2) {
1536         x = mat_T[k+n*(k+1)];
1537         z = mat_T[k+n*(k+2)];
1538       }
1539     }
1540     itr++;
1541   }
1542 
1543   // Save eigenvalues
1544   for (CeedInt i=0; i<n; i++)
1545     lambda[i] = mat_T[i+n*i];
1546 
1547   // Check convergence
1548   if (itr == max_itr && q < n-1)
1549     // LCOV_EXCL_START
1550     return CeedError(ceed, CEED_ERROR_MINOR,
1551                      "Symmetric QR failed to converge");
1552   // LCOV_EXCL_STOP
1553   return CEED_ERROR_SUCCESS;
1554 }
1555 CeedPragmaOptimizeOn
1556 
1557 /**
1558   @brief Return Simultaneous Diagonalization of two matrices. This solves the
1559            generalized eigenvalue problem A x = lambda B x, where A and B
1560            are symmetric and B is positive definite. We generate the matrix X
1561            and vector Lambda such that X^T A X = Lambda and X^T B X = I. This
1562            is equivalent to the LAPACK routine 'sygv' with TYPE = 1.
1563 
1564   @param ceed         A Ceed context for error handling
1565   @param[in] mat_A    Row-major matrix to be factorized with eigenvalues
1566   @param[in] mat_B    Row-major matrix to be factorized to identity
1567   @param[out] mat_X   Row-major orthogonal matrix
1568   @param[out] lambda  Vector of length n of generalized eigenvalues
1569   @param n            Number of rows/columns
1570 
1571   @return An error code: 0 - success, otherwise - failure
1572 
1573   @ref Utility
1574 **/
1575 CeedPragmaOptimizeOff
1576 int CeedSimultaneousDiagonalization(Ceed ceed, CeedScalar *mat_A,
1577                                     CeedScalar *mat_B, CeedScalar *mat_X,
1578                                     CeedScalar *lambda, CeedInt n) {
1579   int ierr;
1580   CeedScalar *mat_C, *mat_G, *vec_D;
1581   ierr = CeedCalloc(n*n, &mat_C); CeedChk(ierr);
1582   ierr = CeedCalloc(n*n, &mat_G); CeedChk(ierr);
1583   ierr = CeedCalloc(n, &vec_D); CeedChk(ierr);
1584 
1585   // Compute B = G D G^T
1586   memcpy(mat_G, mat_B, n*n*sizeof(mat_B[0]));
1587   ierr = CeedSymmetricSchurDecomposition(ceed, mat_G, vec_D, n); CeedChk(ierr);
1588 
1589   // Sort eigenvalues
1590   for (CeedInt i=n-1; i>=0; i--)
1591     for (CeedInt j=0; j<i; j++) {
1592       if (fabs(vec_D[j]) > fabs(vec_D[j+1])) {
1593         CeedScalar temp;
1594         temp = vec_D[j]; vec_D[j] = vec_D[j+1]; vec_D[j+1] = temp;
1595         for (CeedInt k=0; k<n; k++) {
1596           temp = mat_G[k*n+j]; mat_G[k*n+j] = mat_G[k*n+j+1]; mat_G[k*n+j+1] = temp;
1597         }
1598       }
1599     }
1600 
1601   // Compute C = (G D^1/2)^-1 A (G D^1/2)^-T
1602   //           = D^-1/2 G^T A G D^-1/2
1603   // -- D = D^-1/2
1604   for (CeedInt i=0; i<n; i++)
1605     vec_D[i] = 1./sqrt(vec_D[i]);
1606   // -- G = G D^-1/2
1607   // -- C = D^-1/2 G^T
1608   for (CeedInt i=0; i<n; i++)
1609     for (CeedInt j=0; j<n; j++) {
1610       mat_G[i*n+j] *= vec_D[j];
1611       mat_C[j*n+i]  = mat_G[i*n+j];
1612     }
1613   // -- X = (D^-1/2 G^T) A
1614   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_C,
1615                             (const CeedScalar *)mat_A, mat_X, n, n, n);
1616   CeedChk(ierr);
1617   // -- C = (D^-1/2 G^T A) (G D^-1/2)
1618   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_X,
1619                             (const CeedScalar *)mat_G, mat_C, n, n, n);
1620   CeedChk(ierr);
1621 
1622   // Compute Q^T C Q = lambda
1623   ierr = CeedSymmetricSchurDecomposition(ceed, mat_C, lambda, n); CeedChk(ierr);
1624 
1625   // Sort eigenvalues
1626   for (CeedInt i=n-1; i>=0; i--)
1627     for (CeedInt j=0; j<i; j++) {
1628       if (fabs(lambda[j]) > fabs(lambda[j+1])) {
1629         CeedScalar temp;
1630         temp = lambda[j]; lambda[j] = lambda[j+1]; lambda[j+1] = temp;
1631         for (CeedInt k=0; k<n; k++) {
1632           temp = mat_C[k*n+j]; mat_C[k*n+j] = mat_C[k*n+j+1]; mat_C[k*n+j+1] = temp;
1633         }
1634       }
1635     }
1636 
1637   // Set X = (G D^1/2)^-T Q
1638   //       = G D^-1/2 Q
1639   ierr = CeedMatrixMultiply(ceed, (const CeedScalar *)mat_G,
1640                             (const CeedScalar *)mat_C, mat_X, n, n, n);
1641   CeedChk(ierr);
1642 
1643   // Cleanup
1644   ierr = CeedFree(&mat_C); CeedChk(ierr);
1645   ierr = CeedFree(&mat_G); CeedChk(ierr);
1646   ierr = CeedFree(&vec_D); CeedChk(ierr);
1647   return CEED_ERROR_SUCCESS;
1648 }
1649 CeedPragmaOptimizeOn
1650 
1651 /// @}
1652