xref: /libCEED/examples/petsc/qfunctions/bps/bp4sphere.h (revision e0dd07dce7a2b4fea74ab4e50be8fbfb4c0a8e14)
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 bp4sphere_h
21 #define bp4sphere_h
22 #include <ceed.h>
23 
24 #ifndef __CUDACC__
25 #  include <math.h>
26 #endif
27 
28 // *****************************************************************************
29 // This QFunction sets up the rhs and true solution for the problem
30 // *****************************************************************************
31 
32 // -----------------------------------------------------------------------------
33 CEED_QFUNCTION(SetupDiffRhs3)(void *ctx, const CeedInt Q,
34                              const CeedScalar *const *in,
35                              CeedScalar *const *out) {
36   // Inputs
37   const CeedScalar *X = in[0], *qdata = in[1];
38   // Outputs
39   CeedScalar *true_soln = out[0], *rhs = out[1];
40 
41   // Context
42   const CeedScalar *context = (const CeedScalar*)ctx;
43   const CeedScalar R        = context[0];
44 
45   // Quadrature Point Loop
46   CeedPragmaSIMD
47   for (CeedInt i=0; i<Q; i++) {
48     // Read global Cartesian coordinates
49     CeedScalar x = X[i+Q*0], y = X[i+Q*1], z = X[i+Q*2];
50     // Normalize quadrature point coordinates to sphere
51     CeedScalar rad = sqrt(x*x + y*y + z*z);
52     x *= R / rad;
53     y *= R / rad;
54     z *= R / rad;
55     // Compute latitude and longitude
56     const CeedScalar theta  = asin(z / R); // latitude
57     const CeedScalar lambda = atan2(y, x); // longitude
58 
59     // Use absolute value of latitute for true solution
60     // Component 1
61     true_soln[i+0*Q] = sin(lambda) * cos(theta);
62     // Component 2
63     true_soln[i+1*Q] = 2 * true_soln[i+0*Q];
64     // Component 3
65     true_soln[i+2*Q] = 3 * true_soln[i+0*Q];
66 
67     // Component 1
68     rhs[i+0*Q] = qdata[i+Q*0] * 2 * sin(lambda)*cos(theta) / (R*R);
69     // Component 2
70     rhs[i+1*Q] = 2 * rhs[i+0*Q];
71     // Component 3
72     rhs[i+2*Q] = 3 * rhs[i+0*Q];
73   } // End of Quadrature Point Loop
74 
75   return 0;
76 }
77 
78 // *****************************************************************************
79 // This QFunction applies the diffusion operator for a vector field of 3 components.
80 //
81 // Inputs:
82 //   ug     - Input vector Jacobian at quadrature points
83 //   qdata  - Geometric factors
84 //
85 // Output:
86 //   vJ     - Output vector (test functions) Jacobian at quadrature points
87 //
88 // *****************************************************************************
89 
90 // -----------------------------------------------------------------------------
91 CEED_QFUNCTION(Diff3)(void *ctx, const CeedInt Q,
92                       const CeedScalar *const *in, CeedScalar *const *out) {
93   const CeedScalar *ug = in[0], *qdata = in[1];
94   CeedScalar *vJ = out[0];
95 
96   // Quadrature Point Loop
97   CeedPragmaSIMD
98   for (CeedInt i=0; i<Q; i++) {
99     // Read spatial derivatives of u
100     const CeedScalar uJ[3][2]        = {{ug[i+(0+0*3)*Q],
101                                          ug[i+(0+1*3)*Q]},
102                                         {ug[i+(1+0*3)*Q],
103                                          ug[i+(1+1*3)*Q]},
104                                         {ug[i+(2+0*3)*Q],
105                                          ug[i+(2+1*3)*Q]}
106                                        };
107     // Read qdata
108     const CeedScalar wJ              =   qdata[i+Q*0];
109     // -- Grad-to-Grad qdata
110     // ---- dXdx_j,k * dXdx_k,j
111     const CeedScalar dXdxdXdxT[2][2] = {{qdata[i+Q*1],
112                                          qdata[i+Q*3]},
113                                         {qdata[i+Q*3],
114                                          qdata[i+Q*2]}
115                                        };
116 
117     for (int k=0; k<3; k++) // k = component
118       for (int j=0; j<2; j++) // j = direction of vg
119         vJ[i+(k+j*3)*Q] = wJ * (uJ[k][0] * dXdxdXdxT[0][j] +
120                                 uJ[k][1] * dXdxdXdxT[1][j]);
121 
122   } // End of Quadrature Point Loop
123 
124   return 0;
125 }
126 // -----------------------------------------------------------------------------
127 
128 #endif // bp4sphere_h
129