xref: /libCEED/examples/petsc/qfunctions/bps/bp13.h (revision 3c11f1fc4579930f14e261f40b0038a1553ab9e9)
1*3c11f1fcSJeremy L Thompson // Copyright (c) 2017-2025, Lawrence Livermore National Security, LLC and other CEED contributors.
2*3c11f1fcSJeremy L Thompson // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3*3c11f1fcSJeremy L Thompson //
4*3c11f1fcSJeremy L Thompson // SPDX-License-Identifier: BSD-2-Clause
5*3c11f1fcSJeremy L Thompson //
6*3c11f1fcSJeremy L Thompson // This file is part of CEED:  http://github.com/ceed
7*3c11f1fcSJeremy L Thompson 
8*3c11f1fcSJeremy L Thompson /// @file
9*3c11f1fcSJeremy L Thompson /// libCEED QFunctions for diffusion operator example using PETSc
10*3c11f1fcSJeremy L Thompson 
11*3c11f1fcSJeremy L Thompson #include <ceed/types.h>
12*3c11f1fcSJeremy L Thompson #ifndef CEED_RUNNING_JIT_PASS
13*3c11f1fcSJeremy L Thompson #include <math.h>
14*3c11f1fcSJeremy L Thompson #endif
15*3c11f1fcSJeremy L Thompson 
16*3c11f1fcSJeremy L Thompson // -----------------------------------------------------------------------------
17*3c11f1fcSJeremy L Thompson // This QFunction sets up the rhs and true solution for the problem
18*3c11f1fcSJeremy L Thompson // -----------------------------------------------------------------------------
19*3c11f1fcSJeremy L Thompson CEED_QFUNCTION(SetupMassDiffRhs)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
20*3c11f1fcSJeremy L Thompson #ifndef M_PI
21*3c11f1fcSJeremy L Thompson #define M_PI 3.14159265358979323846
22*3c11f1fcSJeremy L Thompson #endif
23*3c11f1fcSJeremy L Thompson   const CeedScalar *x = in[0], *w = in[1];
24*3c11f1fcSJeremy L Thompson   CeedScalar       *true_soln = out[0], *rhs = out[1];
25*3c11f1fcSJeremy L Thompson 
26*3c11f1fcSJeremy L Thompson   // Quadrature Point Loop
27*3c11f1fcSJeremy L Thompson   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
28*3c11f1fcSJeremy L Thompson     const CeedScalar c[3] = {0, 1., 2.};
29*3c11f1fcSJeremy L Thompson     const CeedScalar k[3] = {1., 2., 3.};
30*3c11f1fcSJeremy L Thompson 
31*3c11f1fcSJeremy L Thompson     true_soln[i] = sin(M_PI * (c[0] + k[0] * x[i + Q * 0])) * sin(M_PI * (c[1] + k[1] * x[i + Q * 1])) * sin(M_PI * (c[2] + k[2] * x[i + Q * 2]));
32*3c11f1fcSJeremy L Thompson 
33*3c11f1fcSJeremy L Thompson     rhs[i] = w[i + Q * 0] * (M_PI * M_PI * (k[0] * k[0] + k[1] * k[1] + k[2] * k[2]) + 1.0) * true_soln[i];
34*3c11f1fcSJeremy L Thompson   }  // End of Quadrature Point Loop
35*3c11f1fcSJeremy L Thompson   return 0;
36*3c11f1fcSJeremy L Thompson }
37*3c11f1fcSJeremy L Thompson 
38*3c11f1fcSJeremy L Thompson // -----------------------------------------------------------------------------
39*3c11f1fcSJeremy L Thompson // This QFunction applies the mass + diffusion operator for a scalar field.
40*3c11f1fcSJeremy L Thompson //
41*3c11f1fcSJeremy L Thompson // Inputs:
42*3c11f1fcSJeremy L Thompson //   u       - Input vector at quadrature points
43*3c11f1fcSJeremy L Thompson //   ug      - Input vector gradient at quadrature points
44*3c11f1fcSJeremy L Thompson //   q_data  - Geometric factors
45*3c11f1fcSJeremy L Thompson //
46*3c11f1fcSJeremy L Thompson // Output:
47*3c11f1fcSJeremy L Thompson //   v      - Output vector (test functions) at quadrature points
48*3c11f1fcSJeremy L Thompson //   vg     - Output vector (test functions) gradient at quadrature points
49*3c11f1fcSJeremy L Thompson // -----------------------------------------------------------------------------
50*3c11f1fcSJeremy L Thompson CEED_QFUNCTION(MassDiff)(void *ctx, CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) {
51*3c11f1fcSJeremy L Thompson   const CeedScalar *u = in[0], *ug = in[1], *q_data = in[2];
52*3c11f1fcSJeremy L Thompson   CeedScalar       *v = out[0], *vg = out[1];
53*3c11f1fcSJeremy L Thompson 
54*3c11f1fcSJeremy L Thompson   // Quadrature Point Loop
55*3c11f1fcSJeremy L Thompson   CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) {
56*3c11f1fcSJeremy L Thompson     // Read spatial derivatives of u
57*3c11f1fcSJeremy L Thompson     const CeedScalar du[3] = {ug[i + Q * 0], ug[i + Q * 1], ug[i + Q * 2]};
58*3c11f1fcSJeremy L Thompson     // Read q_data (dXdxdXdx_T symmetric matrix)
59*3c11f1fcSJeremy L Thompson     const CeedScalar dXdxdXdx_T[3][3] = {
60*3c11f1fcSJeremy L Thompson         {q_data[i + 1 * Q], q_data[i + 2 * Q], q_data[i + 3 * Q]},
61*3c11f1fcSJeremy L Thompson         {q_data[i + 2 * Q], q_data[i + 4 * Q], q_data[i + 5 * Q]},
62*3c11f1fcSJeremy L Thompson         {q_data[i + 3 * Q], q_data[i + 5 * Q], q_data[i + 6 * Q]}
63*3c11f1fcSJeremy L Thompson     };
64*3c11f1fcSJeremy L Thompson 
65*3c11f1fcSJeremy L Thompson     // Mass
66*3c11f1fcSJeremy L Thompson     v[i] = q_data[i + 0 * Q] * u[i];
67*3c11f1fcSJeremy L Thompson     // Diff
68*3c11f1fcSJeremy L Thompson     for (int j = 0; j < 3; j++) {  // j = direction of vg
69*3c11f1fcSJeremy L Thompson       vg[i + j * Q] = (du[0] * dXdxdXdx_T[0][j] + du[1] * dXdxdXdx_T[1][j] + du[2] * dXdxdXdx_T[2][j]);
70*3c11f1fcSJeremy L Thompson     }
71*3c11f1fcSJeremy L Thompson   }  // End of Quadrature Point Loop
72*3c11f1fcSJeremy L Thompson   return 0;
73*3c11f1fcSJeremy L Thompson }
74*3c11f1fcSJeremy L Thompson // -----------------------------------------------------------------------------
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