1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
|
/* Copyright 2020 Remi Lehe
*
* This file is part of WarpX.
*
* License: BSD-3-Clause-LBNL
*/
#ifndef WARPX_FINITE_DIFFERENCE_ALGORITHM_YEE_H_
#define WARPX_FINITE_DIFFERENCE_ALGORITHM_YEE_H_
#include <AMReX_REAL.H>
#include <AMReX_Array4.H>
#include <AMReX_Gpu.H>
struct YeeAlgorithm {
static void InitializeStencilCoefficients(
std::array<amrex::Real,3>& cell_size,
amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_x,
amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_y,
amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_z ) {
// Store the inverse cell size along each direction in the coefficients
stencil_coefs_x.resize(1);
stencil_coefs_x[0] = 1./cell_size[0];
stencil_coefs_y.resize(1);
stencil_coefs_y[0] = 1./cell_size[1];
stencil_coefs_z.resize(1);
stencil_coefs_z[0] = 1./cell_size[2];
}
/**
/* Perform derivative along x on a cell-centered grid, from a nodal field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real UpwardDx(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_x, int const n_coefs_x,
int const i, int const j, int const k ) {
amrex::Real const inv_dx = coefs_x[0];
return inv_dx*( F(i+1,j,k) - F(i,j,k) );
};
/**
/* Perform derivative along x on a nodal grid, from a cell-centered field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real DownwardDx(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_x, int const n_coefs_x,
int const i, int const j, int const k ) {
amrex::Real const inv_dx = coefs_x[0];
return inv_dx*( F(i,j,k) - F(i-1,j,k) );
};
/**
/* Perform derivative along y on a cell-centered grid, from a nodal field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real UpwardDy(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_y, int const n_coefs_y,
int const i, int const j, int const k ) {
#if defined WARPX_DIM_3D
amrex::Real const inv_dy = coefs_y[0];
return inv_dy*( F(i,j+1,k) - F(i,j,k) );
#elif (defined WARPX_DIM_XZ)
return 0; // 2D Cartesian: derivative along y is 0
#endif
};
/**
/* Perform derivative along y on a nodal grid, from a cell-centered field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real DownwardDy(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_y, int const n_coefs_y,
int const i, int const j, int const k ) {
#if defined WARPX_DIM_3D
amrex::Real const inv_dy = coefs_y[0];
return inv_dy*( F(i,j,k) - F(i,j-1,k) );
#elif (defined WARPX_DIM_XZ)
return 0; // 2D Cartesian: derivative along y is 0
#endif
};
/**
/* Perform derivative along z on a cell-centered grid, from a nodal field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real UpwardDz(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_z, int const n_coefs_z,
int const i, int const j, int const k ) {
amrex::Real const inv_dz = coefs_z[0];
#if defined WARPX_DIM_3D
return inv_dz*( F(i,j,k+1) - F(i,j,k) );
#elif (defined WARPX_DIM_XZ)
return inv_dz*( F(i,j+1,k) - F(i,j,k) );
#endif
};
/**
/* Perform derivative along z on a nodal grid, from a cell-centered field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real DownwardDz(
amrex::Array4<amrex::Real> const& F,
amrex::Real const* coefs_z, int const n_coefs_z,
int const i, int const j, int const k ) {
amrex::Real const inv_dz = coefs_z[0];
#if defined WARPX_DIM_3D
return inv_dz*( F(i,j,k) - F(i,j,k-1) );
#elif (defined WARPX_DIM_XZ)
return inv_dz*( F(i,j,k) - F(i,j-1,k) );
#endif
};
};
#endif // WARPX_FINITE_DIFFERENCE_ALGORITHM_YEE_H_
|
