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
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/* Copyright (C) 1999-2014 Massachusetts Institute of Technology.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**************************************************************************/
/* This file defines functions to initialize the dielectric function
by reading epsilon values from a file, rather than using the
geometry. Actually, we would like to use the geometry in addition
to the epsilon file, for added flexibility. So, we return an epsilon
function that can be used when no geometric objects are found. */
/**************************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "config.h"
#include <check.h>
#include <mpi_utils.h>
#include <matrices.h>
#include <matrixio.h>
#include <maxwell.h>
#include <ctl.h>
#include "mpb.h"
typedef struct {
int nx, ny, nz;
real *data;
} epsilon_file_data;
/* Linearly interpolate a given point in a 3d grid of data. The point
coordinates should be in the range [0,1], or at the very least [-1,2]
... anything outside [0,1] is *mirror* reflected into [0,1] */
real linear_interpolate(real rx, real ry, real rz,
real *data, int nx, int ny, int nz, int stride)
{
int x, y, z, x2, y2, z2;
real dx, dy, dz;
/* mirror boundary conditions for r just beyond the boundary */
if (rx < 0.0) rx = -rx; else if (rx > 1.0) rx = 1.0 - rx;
if (ry < 0.0) ry = -ry; else if (ry > 1.0) ry = 1.0 - ry;
if (rz < 0.0) rz = -rz; else if (rz > 1.0) rz = 1.0 - rz;
/* get the point corresponding to r in the epsilon array grid: */
x = rx * nx; if (x == nx) --x;
y = ry * ny; if (y == ny) --y;
z = rz * nz; if (z == nz) --z;
/* get the difference between (x,y,z) and the actual point
... we shift by 0.5 to center the data points in the pixels */
dx = rx * nx - x - 0.5;
dy = ry * ny - y - 0.5;
dz = rz * nz - z - 0.5;
/* get the other closest point in the grid, with mirror boundaries: */
x2 = (dx >= 0.0 ? x + 1 : x - 1);
if (x2 < 0) x2++; else if (x2 == nx) x2--;
y2 = (dy >= 0.0 ? y + 1 : y - 1);
if (y2 < 0) y2++; else if (y2 == ny) y2--;
z2 = (dz >= 0.0 ? z + 1 : z - 1);
if (z2 < 0) z2++; else if (z2 == nz) z2--;
/* take abs(d{xyz}) to get weights for {xyz} and {xyz}2: */
dx = fabs(dx);
dy = fabs(dy);
dz = fabs(dz);
/* define a macro to give us data(x,y,z) on the grid,
in row-major order (the order used by HDF5): */
#define D(x,y,z) (data[(((x)*ny + (y))*nz + (z)) * stride])
return(((D(x,y,z)*(1.0-dx) + D(x2,y,z)*dx) * (1.0-dy) +
(D(x,y2,z)*(1.0-dx) + D(x2,y2,z)*dx) * dy) * (1.0-dz) +
((D(x,y,z2)*(1.0-dx) + D(x2,y,z2)*dx) * (1.0-dy) +
(D(x,y2,z2)*(1.0-dx) + D(x2,y2,z2)*dx) * dy) * dz);
#undef D
}
static void epsilon_file_func(symmetric_matrix *eps, symmetric_matrix *eps_inv,
const real r[3], void *edata)
{
epsilon_file_data *d = (epsilon_file_data *) edata;
real rx, ry, rz;
real eps_val;
/* make sure r is positive: */
rx = r[0] >= 0.0 ? r[0] : (r[0] + (1 + (int) (-r[0])));
ry = r[1] >= 0.0 ? r[1] : (r[1] + (1 + (int) (-r[1])));
rz = r[2] >= 0.0 ? r[2] : (r[2] + (1 + (int) (-r[2])));
/* make sure r is in [0,1) */
rx = rx < 1.0 ? rx : rx - ((int) rx);
ry = ry < 1.0 ? ry : ry - ((int) ry);
rz = rz < 1.0 ? rz : rz - ((int) rz);
eps_val = linear_interpolate(rx,ry,rz, d->data, d->nx,d->ny,d->nz, 1);
eps->m00 = eps->m11 = eps->m22 = eps_val;
eps_inv->m00 = eps_inv->m11 = eps_inv->m22 = 1.0 / eps_val;
#ifdef WITH_HERMITIAN_EPSILON
CASSIGN_ZERO(eps->m01);
CASSIGN_ZERO(eps->m02);
CASSIGN_ZERO(eps->m12);
CASSIGN_ZERO(eps_inv->m01);
CASSIGN_ZERO(eps_inv->m02);
CASSIGN_ZERO(eps_inv->m12);
#else
eps->m01 = eps->m02 = eps->m12 = 0.0;
eps_inv->m01 = eps_inv->m02 = eps_inv->m12 = 0.0;
#endif
}
void get_epsilon_file_func(const char *fname,
maxwell_dielectric_function *func,
void **func_data)
{
if (fname && fname[0]) {
char *eps_fname;
matrixio_id file_id;
epsilon_file_data *d;
int rank = 3, dims[3];
CHK_MALLOC(d, epsilon_file_data, 1);
eps_fname = ctl_fix_path(fname);
mpi_one_printf("Using background dielectric from file \"%s\"...\n",
eps_fname);
file_id = matrixio_open(eps_fname, 1);
free(eps_fname);
d->data = matrixio_read_real_data(file_id, NULL, &rank, dims,
0,0,0, NULL);
CHECK(d->data, "couldn't find dataset in dielectric file");
matrixio_close(file_id);
d->nx = rank >= 1 ? dims[0] : 1;
d->ny = rank >= 2 ? dims[1] : 1;
d->nz = rank >= 3 ? dims[2] : 1;
mpi_one_printf(" ...read %dx%dx%d dielectric function\n",
d->nx, d->ny, d->nz);
*func = epsilon_file_func;
*func_data = (void*) d;
}
else {
*func = NULL;
*func_data = NULL;
}
}
void destroy_epsilon_file_func_data(void *func_data)
{
epsilon_file_data *d = (epsilon_file_data *) func_data;
if (d) {
free(d->data);
free(d);
}
}
|
