xref: /libCEED/examples/petsc/qfunctions/bps/bp2sphere.h (revision 4ec08b3aede85e944bebadf11512c57780813ef2)
1 // Copyright (c) 2017, Lawrence Livermore National Security, LLC. Produced at
2 // the Lawrence Livermore National Laboratory. LLNL-CODE-734707. All Rights
3 // reserved. See files LICENSE and NOTICE for details.
4 //
5 // This file is part of CEED, a collection of benchmarks, miniapps, software
6 // libraries and APIs for efficient high-order finite element and spectral
7 // element discretizations for exascale applications. For more information and
8 // source code availability see http://github.com/ceed.
9 //
10 // The CEED research is supported by the Exascale Computing Project 17-SC-20-SC,
11 // a collaborative effort of two U.S. Department of Energy organizations (Office
12 // of Science and the National Nuclear Security Administration) responsible for
13 // the planning and preparation of a capable exascale ecosystem, including
14 // software, applications, hardware, advanced system engineering and early
15 // testbed platforms, in support of the nation's exascale computing imperative.
16 
17 /// @file
18 /// libCEED QFunctions for mass operator example for a vector field on the sphere using PETSc
19 
20 #ifndef __CUDACC__
21 #  include <math.h>
22 #endif
23 
24 // *****************************************************************************
25 // This QFunction sets up the rhs and true solution for the problem
26 // *****************************************************************************
27 
28 // -----------------------------------------------------------------------------
29 CEED_QFUNCTION(SetupMassRhs3)(void *ctx, const CeedInt Q,
30                              const CeedScalar *const *in,
31                              CeedScalar *const *out) {
32   // Inputs
33   const CeedScalar *X = in[0], *qdata = in[1];
34   // Outputs
35   CeedScalar *true_soln = out[0], *rhs = out[1];
36 
37   // Context
38   const CeedScalar *context = (const CeedScalar*)ctx;
39   const CeedScalar R        = context[0];
40 
41   // Quadrature Point Loop
42   CeedPragmaSIMD
43   for (CeedInt i=0; i<Q; i++) {
44     // Compute latitude
45     const CeedScalar theta =  asin(X[i+2*Q] / R);
46 
47     // Use absolute value of latitute for true solution
48     // Component 1
49     true_soln[i+0*Q] = fabs(theta);
50     // Component 2
51     true_soln[i+1*Q] = 2 * true_soln[i+0*Q];
52     // Component 3
53     true_soln[i+2*Q] = 3 * true_soln[i+0*Q];
54 
55     // Component 1
56     rhs[i+0*Q] = qdata[i] * true_soln[i];
57     // Component 2
58     rhs[i+1*Q] = 2 * rhs[i+0*Q];
59     // Component 3
60     rhs[i+2*Q] = 3 * rhs[i+0*Q];
61   } // End of Quadrature Point Loop
62 
63   return 0;
64 }
65 
66 // *****************************************************************************
67 // This QFunction applies the mass operator for a vector field of 3 components.
68 //
69 // Inputs:
70 //   u     - Input vector at quadrature points
71 //   qdata - Geometric factors
72 //
73 // Output:
74 //   v     - Output vector (test functions) at quadrature points
75 //
76 // *****************************************************************************
77 
78 // -----------------------------------------------------------------------------
79 CEED_QFUNCTION(Mass3)(void *ctx, const CeedInt Q,
80                       const CeedScalar *const *in, CeedScalar *const *out) {
81   const CeedScalar *u = in[0], *qdata = in[1];
82   CeedScalar *v = out[0];
83 
84   // Quadrature Point Loop
85   CeedPragmaSIMD
86   for (CeedInt i=0; i<Q; i++) {
87     const CeedScalar r = qdata[i];
88     // Component 1
89     v[i+0*Q] = r * u[i+0*Q];
90     // Component 2
91     v[i+1*Q] = r * u[i+1*Q];
92     // Component 3
93     v[i+2*Q] = r * u[i+2*Q];
94   } // End of Quadrature Point Loop
95 
96   return 0;
97 }
98 // -----------------------------------------------------------------------------
99