1 // Copyright (c) 2017-2024, 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 /// @file 9 /// libCEED QFunctions for mass operator example using PETSc 10 11 #include <ceed.h> 12 #include <math.h> 13 14 // ----------------------------------------------------------------------------- 15 // This QFunction sets up the geometric factors required to apply the mass operator 16 // 17 // The quadrature data is stored in the array q_data. 18 // 19 // We require the determinant of the Jacobian to properly compute integrals of the form: int( u v ) 20 // 21 // Qdata: det_J * w 22 // 23 // ----------------------------------------------------------------------------- 24 CEED_QFUNCTION(SetupMassGeo)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 25 // Inputs 26 const CeedScalar(*J)[3][CEED_Q_VLA] = (const CeedScalar(*)[3][CEED_Q_VLA])in[1]; 27 const CeedScalar(*w) = in[2]; // Note: *X = in[0] 28 // Outputs 29 CeedScalar *q_data = out[0]; 30 31 const CeedInt dim = 3; 32 // Quadrature Point Loop 33 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 34 // Setup 35 CeedScalar A[3][3]; 36 for (CeedInt j = 0; j < dim; j++) { 37 for (CeedInt k = 0; k < dim; k++) { 38 // Equivalent code with no mod operations: 39 // A[k][j] = J[k+1][j+1]*J[k+2][j+2] - J[k+1][j+2]*J[k+2][j+1] 40 A[k][j] = J[(k + 1) % dim][(j + 1) % dim][i] * J[(k + 2) % dim][(j + 2) % dim][i] - 41 J[(k + 1) % dim][(j + 2) % dim][i] * J[(k + 2) % dim][(j + 1) % dim][i]; 42 } 43 } 44 const CeedScalar detJ = J[0][0][i] * A[0][0] + J[0][1][i] * A[0][1] + J[0][2][i] * A[0][2]; 45 q_data[i] = detJ * w[i]; 46 } // End of Quadrature Point Loop 47 return 0; 48 } 49 50 // ----------------------------------------------------------------------------- 51 // This QFunction sets up the rhs and true solution for the problem 52 // ----------------------------------------------------------------------------- 53 CEED_QFUNCTION(SetupMassRhs)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 54 const CeedScalar *x = in[0], *w = in[1]; 55 CeedScalar *true_soln = out[0], *rhs = out[1]; 56 57 // Quadrature Point Loop 58 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) { 59 true_soln[i] = sqrt(x[i] * x[i] + x[i + Q] * x[i + Q] + x[i + 2 * Q] * x[i + 2 * Q]); 60 rhs[i] = w[i] * true_soln[i]; 61 } // End of Quadrature Point Loop 62 return 0; 63 } 64 65 // ----------------------------------------------------------------------------- 66 // This QFunction applies the mass operator for a scalar field. 67 // 68 // Inputs: 69 // u - Input vector at quadrature points 70 // q_data - Geometric factors 71 // 72 // Output: 73 // v - Output vector (test functions) at quadrature points 74 // ----------------------------------------------------------------------------- 75 CEED_QFUNCTION(Mass)(void *ctx, const CeedInt Q, const CeedScalar *const *in, CeedScalar *const *out) { 76 const CeedScalar *u = in[0], *q_data = in[1]; 77 CeedScalar *v = out[0]; 78 79 // Quadrature Point Loop 80 CeedPragmaSIMD for (CeedInt i = 0; i < Q; i++) v[i] = q_data[i] * u[i]; 81 82 return 0; 83 } 84 // ----------------------------------------------------------------------------- 85