xref: /libCEED/examples/fluids/qfunctions/utils.h (revision e26ec02599109ff3515b5118893f538030923aec)
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 #ifndef utils_h
9 #define utils_h
10 
11 #include <ceed.h>
12 #include <math.h>
13 
14 #ifndef M_PI
15 #define M_PI    3.14159265358979323846
16 #endif
17 
18 CEED_QFUNCTION_HELPER CeedScalar Max(CeedScalar a, CeedScalar b) { return a < b ? b : a; }
19 CEED_QFUNCTION_HELPER CeedScalar Min(CeedScalar a, CeedScalar b) { return a < b ? a : b; }
20 
21 CEED_QFUNCTION_HELPER CeedScalar Square(CeedScalar x) { return x*x; }
22 CEED_QFUNCTION_HELPER CeedScalar Cube(CeedScalar x) { return x*x*x; }
23 
24 // @brief Dot product of 3 element vectors
25 CEED_QFUNCTION_HELPER CeedScalar Dot3(const CeedScalar u[3],
26                                       const CeedScalar v[3]) {
27   return u[0]*v[0] + u[1]*v[1] + u[2]*v[2];
28 }
29 
30 // @brief Unpack Kelvin-Mandel notation symmetric tensor into full tensor
31 CEED_QFUNCTION_HELPER void KMUnpack(const CeedScalar v[6], CeedScalar A[3][3]) {
32   const CeedScalar weight = 1 / sqrt(2.);
33   A[0][0] = v[0];
34   A[1][1] = v[1];
35   A[2][2] = v[2];
36   A[2][1] = A[1][2] = weight * v[3];
37   A[2][0] = A[0][2] = weight * v[4];
38   A[1][0] = A[0][1] = weight * v[5];
39 }
40 
41 #endif // utils_h
42