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
|
/* Copyright 2020 Remi Lehe
*
* This file is part of WarpX.
*
* License: BSD-3-Clause-LBNL
*/
#ifndef WARPX_FINITE_DIFFERENCE_ALGORITHM_CYLINDRICAL_YEE_H_
#define WARPX_FINITE_DIFFERENCE_ALGORITHM_CYLINDRICAL_YEE_H_
#include <AMReX_REAL.H>
#include <AMReX_Array4.H>
#include <AMReX_Gpu.H>
/**
* This struct contains only static functions to initialize the stencil coefficients
* and to compute finite-difference derivatives for the Cartesian Yee algorithm.
*/
struct CylindricalYeeAlgorithm {
static void InitializeStencilCoefficients (
std::array<amrex::Real,3>& cell_size,
amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_r,
amrex::Gpu::ManagedVector<amrex::Real>& stencil_coefs_z ) {
// Store the inverse cell size along each direction in the coefficients
stencil_coefs_r.resize(1);
stencil_coefs_r[0] = 1./cell_size[0]; // 1./dr
stencil_coefs_z.resize(1);
stencil_coefs_z[0] = 1./cell_size[2]; // 1./dz
}
/** Applies the differential operator `1/r * d(rF)/dr`,
* where `F` is on a *nodal* grid in `r`
* and the differential operator is evaluated on a *cell-centered* grid.
* The input parameter `r` is given at the cell-centered position */
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real UpwardDrr_over_r (
amrex::Array4<amrex::Real> const& F,
amrex::Real const r, amrex::Real const dr,
amrex::Real const * const coefs_r, int const n_coefs_r,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dr = coefs_r[0];
return 1./r * inv_dr*( (r+0.5*dr)*F(i+1,j,k,comp) - (r-0.5*dr)*F(i,j,k,comp) );
};
/** Applies the differential operator `1/r * d(rF)/dr`,
* where `F` is on a *cell-centered* grid in `r`
* and the differential operator is evaluated on a *nodal* grid.
* The input parameter `r` is given at the cell-centered position */
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real DownwardDrr_over_r (
amrex::Array4<amrex::Real> const& F,
amrex::Real const r, amrex::Real const dr,
amrex::Real const * const coefs_r, int const n_coefs_r,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dr = coefs_r[0];
return 1./r * inv_dr*( (r+0.5*dr)*F(i,j,k,comp) - (r-0.5*dr)*F(i-1,j,k,comp) );
};
/**
/* Perform derivative along r on a cell-centered grid, from a nodal field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real UpwardDr (
amrex::Array4<amrex::Real> const& F,
amrex::Real const * const coefs_r, int const n_coefs_r,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dr = coefs_r[0];
return inv_dr*( F(i+1,j,k,comp) - F(i,j,k,comp) );
};
/**
/* Perform derivative along r on a nodal grid, from a cell-centered field `F`*/
AMREX_GPU_HOST_DEVICE AMREX_FORCE_INLINE
static amrex::Real DownwardDr (
amrex::Array4<amrex::Real> const& F,
amrex::Real const * const coefs_r, int const n_coefs_r,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dr = coefs_r[0];
return inv_dr*( F(i,j,k,comp) - F(i-1,j,k,comp) );
};
/**
/* 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 * const coefs_z, int const n_coefs_z,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dz = coefs_z[0];
return inv_dz*( F(i,j+1,k,comp) - F(i,j,k,comp) );
};
/**
/* 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 * const coefs_z, int const n_coefs_z,
int const i, int const j, int const k, int const comp ) {
amrex::Real const inv_dz = coefs_z[0];
return inv_dz*( F(i,j,k,comp) - F(i,j-1,k,comp) );
};
};
#endif // WARPX_FINITE_DIFFERENCE_ALGORITHM_CYLINDRICAL_YEE_H_
|
