xref: /libCEED/tests/t531-operator.h (revision cd4035ff32b1ddface7e7603292a8647e8b8628f) !
1 // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2 // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
3 //
4 // SPDX-License-Identifier: BSD-2-Clause
5 //
6 // This file is part of CEED:  http://github.com/ceed
7 
8 #include <ceed.h>
9 
10 CEED_QFUNCTION(setup)(void *ctx, const CeedInt Q,
11                       const CeedScalar *const *in,
12                       CeedScalar *const *out) {
13   // At every quadrature point, compute qw/det(J).adj(J).adj(J)^T and store
14   // the symmetric part of the result.
15 
16   // in[0] is Jacobians with shape [2, nc=2, Q]
17   // in[1] is quadrature weights, size (Q)
18   const CeedScalar *J = in[0], *qw = in[1];
19 
20   // out[0] is qdata, size (Q)
21   CeedScalar *qd = out[0];
22 
23   // Quadrature point loop
24   for (CeedInt i=0; i<Q; i++) {
25     // J: 0 2   qd: 0 2   adj(J):  J22 -J12
26     //    1 3       2 1           -J21  J11
27     const CeedScalar J11 = J[i+Q*0];
28     const CeedScalar J21 = J[i+Q*1];
29     const CeedScalar J12 = J[i+Q*2];
30     const CeedScalar J22 = J[i+Q*3];
31     const CeedScalar w = qw[i] / (J11*J22 - J21*J12);
32     qd[i+Q*0] =   w * (J12*J12 + J22*J22);
33     qd[i+Q*2] =   w * (J11*J11 + J21*J21);
34     qd[i+Q*1] = - w * (J11*J12 + J21*J22);
35   }
36 
37   return 0;
38 }
39 
40 CEED_QFUNCTION(diff)(void *ctx, const CeedInt Q, const CeedScalar *const *in,
41                      CeedScalar *const *out) {
42   // in[0] is gradient u, shape [2, nc=1, Q]
43   // in[1] is quadrature data, size (3*Q)
44   const CeedScalar *du = in[0], *qd = in[1];
45 
46   // out[0] is output to multiply against gradient v, shape [2, nc=1, Q]
47   CeedScalar *dv = out[0];
48 
49   // Quadrature point loop
50   for (CeedInt i=0; i<Q; i++) {
51     const CeedScalar du0 = du[i+Q*0];
52     const CeedScalar du1 = du[i+Q*1];
53     dv[i+Q*0] = qd[i+Q*0]*du0 + qd[i+Q*2]*du1;
54     dv[i+Q*1] = qd[i+Q*2]*du0 + qd[i+Q*1]*du1;
55   }
56 
57   return 0;
58 }
59 
60 CEED_QFUNCTION(diff_lin)(void *ctx, const CeedInt Q,
61                          const CeedScalar *const *in, CeedScalar *const *out) {
62   // in[0] is gradient u, shape [2, nc=1, Q]
63   // in[1] is quadrature data, size (4*Q)
64   const CeedScalar *du = in[0], *qd = in[1];
65 
66   // out[0] is output to multiply against gradient v, shape [2, nc=1, Q]
67   CeedScalar *dv = out[0];
68 
69   // Quadrature point loop
70   for (CeedInt i=0; i<Q; i++) {
71     const CeedScalar du0 = du[i+Q*0];
72     const CeedScalar du1 = du[i+Q*1];
73     // Linearized Qdata is provided column-major
74     //  0 2
75     //  1 3
76     dv[i+Q*0] = qd[i+Q*0]*du0 + qd[i+Q*2]*du1;
77     dv[i+Q*1] = qd[i+Q*1]*du0 + qd[i+Q*3]*du1;
78   }
79 
80   return 0;
81 }
82