19ba83ac0SJeremy L Thompson // Copyright (c) 2017-2026, Lawrence Livermore National Security, LLC and other CEED contributors.
2a0154adeSJed Brown // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3a0154adeSJed Brown //
4a0154adeSJed Brown // SPDX-License-Identifier: BSD-2-Clause
5a0154adeSJed Brown //
6a0154adeSJed Brown // This file is part of CEED: http://github.com/ceed
7a0154adeSJed Brown
8a0154adeSJed Brown /**
9a0154adeSJed Brown @brief Ceed QFunction for building the geometric data for the 2D Poisson operator
10a0154adeSJed Brown **/
11c0b5abf0SJeremy L Thompson #include <ceed/types.h>
12c9c2c079SJeremy L Thompson
Poisson2DBuild(void * ctx,const CeedInt Q,const CeedScalar * const * in,CeedScalar * const * out)132b730f8bSJeremy L Thompson CEED_QFUNCTION(Poisson2DBuild)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
14a0154adeSJed Brown // At every quadrature point, compute w/det(J).adj(J).adj(J)^T and store
15a0154adeSJed Brown // the symmetric part of the result.
16a0154adeSJed Brown // in[0] is Jacobians with shape [2, nc=2, Q]
17a0154adeSJed Brown // in[1] is quadrature weights, size (Q)
182b730f8bSJeremy L Thompson const CeedScalar(*J)[2][CEED_Q_VLA] = (const CeedScalar(*)[2][CEED_Q_VLA])in[0], *w = in[1];
19a0154adeSJed Brown // out[0] is qdata, size (3*Q)
20a0154adeSJed Brown CeedScalar(*q_data)[CEED_Q_VLA] = (CeedScalar(*)[CEED_Q_VLA])out[0];
21a0154adeSJed Brown
22a0154adeSJed Brown // Quadrature point loop
232b730f8bSJeremy L Thompson CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
24a0154adeSJed Brown // Qdata stored in Voigt convention
25a0154adeSJed Brown // J: 0 2 q_data: 0 2 adj(J): J11 -J01
26a0154adeSJed Brown // 1 3 2 1 -J10 J00
27a0154adeSJed Brown const CeedScalar J00 = J[0][0][i];
28a0154adeSJed Brown const CeedScalar J10 = J[0][1][i];
29a0154adeSJed Brown const CeedScalar J01 = J[1][0][i];
30a0154adeSJed Brown const CeedScalar J11 = J[1][1][i];
31a0154adeSJed Brown const CeedScalar qw = w[i] / (J00 * J11 - J10 * J01);
32*6261a418SJeremy L Thompson
33a0154adeSJed Brown q_data[0][i] = qw * (J01 * J01 + J11 * J11);
34a0154adeSJed Brown q_data[1][i] = qw * (J00 * J00 + J10 * J10);
35a0154adeSJed Brown q_data[2][i] = -qw * (J00 * J01 + J10 * J11);
36a0154adeSJed Brown } // End of Quadrature Point Loop
37a0154adeSJed Brown return CEED_ERROR_SUCCESS;
38a0154adeSJed Brown }
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