blob: 0112ebd55e8ebfc2651e8ac01f3f3cd8db5c5393 (
plain)
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
|
/* Copyright (c) 2019, Anthony Latorre <tlatorre at uchicago>
*
* 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 3 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, see <https://www.gnu.org/licenses/>.
*/
#include "random.h"
#include <math.h>
double randn(void)
{
/* Generates a random number from a normal distribution using the
* Box-Muller transform. */
double u1, u2;
u1 = genrand_real1();
u2 = genrand_real1();
return sqrt(-2*log(u1))*cos(2*M_PI*u2);
}
void rand_sphere(double *dir)
{
/* Generates a random point on the unit sphere. */
double u, v, theta, phi;
u = genrand_real1();
v = genrand_real1();
phi = 2*M_PI*u;
theta = acos(2*v-1);
dir[0] = sin(theta)*cos(phi);
dir[1] = sin(theta)*sin(phi);
dir[2] = cos(theta);
}
|
