xref: /libCEED/tests/t541-operator.h (revision 3d8e882215d238700cdceb37404f76ca7fa24eaa)
1*3d8e8822SJeremy L Thompson // Copyright (c) 2017-2022, Lawrence Livermore National Security, LLC and other CEED contributors.
2*3d8e8822SJeremy L Thompson // All Rights Reserved. See the top-level LICENSE and NOTICE files for details.
315ed3f7dSjeremylt //
4*3d8e8822SJeremy L Thompson // SPDX-License-Identifier: BSD-2-Clause
515ed3f7dSjeremylt //
6*3d8e8822SJeremy L Thompson // This file is part of CEED:  http://github.com/ceed
715ed3f7dSjeremylt 
815ed3f7dSjeremylt CEED_QFUNCTION(setup_diff)(void *ctx, const CeedInt Q,
915ed3f7dSjeremylt                            const CeedScalar *const *in,
1015ed3f7dSjeremylt                            CeedScalar *const *out) {
1115ed3f7dSjeremylt   // in[0] is Jacobians with shape [2, nc=2, Q]
1215ed3f7dSjeremylt   // in[1] is quadrature weights, size (Q)
1315ed3f7dSjeremylt   const CeedScalar *J = in[0], *w = in[1];
1415ed3f7dSjeremylt 
1515ed3f7dSjeremylt   // out[0] is qdata, size (Q)
1615ed3f7dSjeremylt   CeedScalar *q_data = out[0];
1715ed3f7dSjeremylt 
1815ed3f7dSjeremylt   // Quadrature point loop
1915ed3f7dSjeremylt   CeedPragmaSIMD
2015ed3f7dSjeremylt   for (CeedInt i=0; i<Q; i++) {
2115ed3f7dSjeremylt     // Qdata stored in Voigt convention
2215ed3f7dSjeremylt     // J: 0 2   q_data: 0 2   adj(J):  J22 -J12
2315ed3f7dSjeremylt     //    1 3           2 1           -J21  J11
2415ed3f7dSjeremylt     const CeedScalar J11 = J[i+Q*0];
2515ed3f7dSjeremylt     const CeedScalar J21 = J[i+Q*1];
2615ed3f7dSjeremylt     const CeedScalar J12 = J[i+Q*2];
2715ed3f7dSjeremylt     const CeedScalar J22 = J[i+Q*3];
2815ed3f7dSjeremylt     const CeedScalar qw = w[i] / (J11*J22 - J21*J12);
2915ed3f7dSjeremylt     q_data[i+Q*0] =   qw * (J12*J12 + J22*J22);
3015ed3f7dSjeremylt     q_data[i+Q*1] =   qw * (J11*J11 + J21*J21);
3115ed3f7dSjeremylt     q_data[i+Q*2] = - qw * (J11*J12 + J21*J22);
3215ed3f7dSjeremylt   } // End of Quadrature Point Loop
3315ed3f7dSjeremylt   return 0;
3415ed3f7dSjeremylt }
3515ed3f7dSjeremylt 
3615ed3f7dSjeremylt CEED_QFUNCTION(apply)(void *ctx, const CeedInt Q, const CeedScalar *const *in,
3715ed3f7dSjeremylt                       CeedScalar *const *out) {
3815ed3f7dSjeremylt   // in[0] is gradient u, shape [2, nc=1, Q]
3915ed3f7dSjeremylt   // in[1] is quadrature data, size (3*Q)
4015ed3f7dSjeremylt   const CeedScalar *ug = in[0], *q_data = in[1];
4115ed3f7dSjeremylt 
4215ed3f7dSjeremylt   // out[0] is output to multiply against gradient v, shape [2, nc=1, Q]
4315ed3f7dSjeremylt   CeedScalar *vg = out[0];
4415ed3f7dSjeremylt 
4515ed3f7dSjeremylt   // Quadrature point loop
4615ed3f7dSjeremylt   CeedPragmaSIMD
4715ed3f7dSjeremylt   for (CeedInt i=0; i<Q; i++) {
4815ed3f7dSjeremylt     // Read spatial derivatives of u
4915ed3f7dSjeremylt     const CeedScalar du[2]        =  {ug[i+Q*0],
5015ed3f7dSjeremylt                                       ug[i+Q*1]
5115ed3f7dSjeremylt                                      };
5215ed3f7dSjeremylt 
5315ed3f7dSjeremylt     // Read qdata (dXdxdXdxT symmetric matrix)
5415ed3f7dSjeremylt     // Stored in Voigt convention
5515ed3f7dSjeremylt     // 0 2
5615ed3f7dSjeremylt     // 2 1
5715ed3f7dSjeremylt     // *INDENT-OFF*
5815ed3f7dSjeremylt     const CeedScalar dXdxdXdxT[2][2] = {{q_data[i+0*Q],
5915ed3f7dSjeremylt                                          q_data[i+2*Q]},
6015ed3f7dSjeremylt                                         {q_data[i+2*Q],
6115ed3f7dSjeremylt                                          q_data[i+1*Q]}
6215ed3f7dSjeremylt                                        };
6315ed3f7dSjeremylt     // *INDENT-ON*
6415ed3f7dSjeremylt 
6515ed3f7dSjeremylt     // Apply Poisson operator
6615ed3f7dSjeremylt     // j = direction of vg
6715ed3f7dSjeremylt     for (int j=0; j<2; j++)
6815ed3f7dSjeremylt       vg[i+j*Q] = (du[0] * dXdxdXdxT[0][j] +
6915ed3f7dSjeremylt                    du[1] * dXdxdXdxT[1][j]);
7015ed3f7dSjeremylt   } // End of Quadrature Point Loop
7115ed3f7dSjeremylt   return 0;
7215ed3f7dSjeremylt }
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