double gauss_rnd_bell( /* Return: Random number */
RAND_GENERATOR * G)
{ /* Inout: generator parameters */
double sample = 0.0;
double x1, x2;
switch (G->uniform) {
case LCG1: /* Chose single LCG uniform generator */
if (G->sigma_range < 1) {
x1 = uniform_rnd_1(G);
x2 = uniform_rnd_1(G);
sample = sqrt(-2 * log(x1)) * cos(2 * M_PI * x2);
}
else {
do {
x1 = uniform_rnd_1(G);
x2 = uniform_rnd_1(G);
sample = sqrt(-2 * log(x1)) * cos(2 * M_PI * x2);
} while (sample < -G->sigma_range || sample > G->sigma_range);
}
break;
case TRIPLE: /* Chose Triple LCG uniform generator */
if (G->sigma_range < 1) {
x1 = uniform_rnd_triple(G);
x2 = uniform_rnd_triple(G);
sample = sqrt(-2 * log(x1)) * cos(2 * M_PI * x2);
}
else {
do {
x1 = uniform_rnd_triple(G);
x2 = uniform_rnd_triple(G);
sample = sqrt(-2 * log(x1)) * cos(2 * M_PI * x2);
} while (sample < -G->sigma_range || sample > G->sigma_range);
}
break;
}
return (sample);
}
double gauss_rnd_pseudo( /* Return: random number */
RAND_GENERATOR * G)
{ /* Inout: generator parameters */
double sample = 0.0;
int i;
switch (G->uniform) {
case LCG1: /* Chose LCG uniform generator */
for (i = 0; i < 2 * G->sigma_range; i++) {
sample += uniform_rnd_1(G);
}
sample = (sample - (double) G->sigma_range);
break;
case TRIPLE: /* Chose Triple LCG uniform generator */
for (i = 0; i < 2 * G->sigma_range; i++) {
sample += uniform_rnd_triple(G);
}
sample = (sample - (double) G->sigma_range);
break;
}
return (sample);
}