void librdist_laplace(gsl_rng *rng, int argc, void *argv, int bufc, float *buf){
t_atom *av = (t_atom *)argv;
if(argc != librdist_getnargs(ps_laplace)){
return;
}
const double a = librdist_atom_getfloat(av);
int i;
for(i = 0; i < bufc; i++)
buf[i] = (float)gsl_ran_laplace(rng, a);
}
int
main (int argc, char *argv[])
{
size_t i,j;
size_t n = 0;
double mu = 0, nu = 0, nu1 = 0, nu2 = 0, sigma = 0, a = 0, b = 0, c = 0;
double zeta = 0, sigmax = 0, sigmay = 0, rho = 0;
double p = 0;
double x = 0, y =0, z=0 ;
unsigned int N = 0, t = 0, n1 = 0, n2 = 0 ;
unsigned long int seed = 0 ;
const char * name ;
gsl_rng * r ;
if (argc < 4)
{
printf (
"Usage: gsl-randist seed n DIST param1 param2 ...\n"
"Generates n samples from the distribution DIST with parameters param1,\n"
"param2, etc. Valid distributions are,\n"
"\n"
" beta\n"
" binomial\n"
" bivariate-gaussian\n"
" cauchy\n"
" chisq\n"
" dir-2d\n"
" dir-3d\n"
" dir-nd\n"
" erlang\n"
" exponential\n"
" exppow\n"
" fdist\n"
" flat\n"
" gamma\n"
" gaussian-tail\n"
" gaussian\n"
" geometric\n"
" gumbel1\n"
" gumbel2\n"
" hypergeometric\n"
" laplace\n"
" landau\n"
" levy\n"
" levy-skew\n"
" logarithmic\n"
" logistic\n"
" lognormal\n"
" negative-binomial\n"
" pareto\n"
" pascal\n"
" poisson\n"
" rayleigh-tail\n"
" rayleigh\n"
" tdist\n"
" ugaussian-tail\n"
" ugaussian\n"
" weibull\n") ;
exit (0);
}
argv++ ; seed = atol (argv[0]); argc-- ;
argv++ ; n = atol (argv[0]); argc-- ;
argv++ ; name = argv[0] ; argc-- ; argc-- ;
gsl_rng_env_setup() ;
if (gsl_rng_default_seed != 0) {
fprintf(stderr,
"overriding GSL_RNG_SEED with command line value, seed = %ld\n",
seed) ;
}
gsl_rng_default_seed = seed ;
r = gsl_rng_alloc(gsl_rng_default) ;
#define NAME(x) !strcmp(name,(x))
#define OUTPUT(x) for (i = 0; i < n; i++) { printf("%g\n", (x)) ; }
#define OUTPUT1(a,x) for(i = 0; i < n; i++) { a ; printf("%g\n", x) ; }
#define OUTPUT2(a,x,y) for(i = 0; i < n; i++) { a ; printf("%g %g\n", x, y) ; }
#define OUTPUT3(a,x,y,z) for(i = 0; i < n; i++) { a ; printf("%g %g %g\n", x, y, z) ; }
#define INT_OUTPUT(x) for (i = 0; i < n; i++) { printf("%d\n", (x)) ; }
#define ARGS(x,y) if (argc != x) error(y) ;
#define DBL_ARG(x) if (argc) { x=atof((++argv)[0]);argc--;} else {error( #x);};
#define INT_ARG(x) if (argc) { x=atoi((++argv)[0]);argc--;} else {error( #x);};
if (NAME("bernoulli"))
{
ARGS(1, "p = probability of success");
DBL_ARG(p)
INT_OUTPUT(gsl_ran_bernoulli (r, p));
}
else if (NAME("beta"))
{
ARGS(2, "a,b = shape parameters");
DBL_ARG(a)
DBL_ARG(b)
OUTPUT(gsl_ran_beta (r, a, b));
}
else if (NAME("binomial"))
{
ARGS(2, "p = probability, N = number of trials");
DBL_ARG(p)
INT_ARG(N)
INT_OUTPUT(gsl_ran_binomial (r, p, N));
}
else if (NAME("cauchy"))
{
ARGS(1, "a = scale parameter");
DBL_ARG(a)
OUTPUT(gsl_ran_cauchy (r, a));
}
else if (NAME("chisq"))
{
ARGS(1, "nu = degrees of freedom");
DBL_ARG(nu)
OUTPUT(gsl_ran_chisq (r, nu));
}
else if (NAME("erlang"))
{
ARGS(2, "a = scale parameter, b = order");
DBL_ARG(a)
DBL_ARG(b)
OUTPUT(gsl_ran_erlang (r, a, b));
}
else if (NAME("exponential"))
{
ARGS(1, "mu = mean value");
DBL_ARG(mu) ;
OUTPUT(gsl_ran_exponential (r, mu));
}
else if (NAME("exppow"))
{
ARGS(2, "a = scale parameter, b = power (1=exponential, 2=gaussian)");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_exppow (r, a, b));
}
else if (NAME("fdist"))
{
ARGS(2, "nu1, nu2 = degrees of freedom parameters");
DBL_ARG(nu1) ;
DBL_ARG(nu2) ;
OUTPUT(gsl_ran_fdist (r, nu1, nu2));
}
else if (NAME("flat"))
{
ARGS(2, "a = lower limit, b = upper limit");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_flat (r, a, b));
}
else if (NAME("gamma"))
{
ARGS(2, "a = order, b = scale");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_gamma (r, a, b));
}
else if (NAME("gaussian"))
{
ARGS(1, "sigma = standard deviation");
DBL_ARG(sigma) ;
OUTPUT(gsl_ran_gaussian (r, sigma));
}
else if (NAME("gaussian-tail"))
{
ARGS(2, "a = lower limit, sigma = standard deviation");
DBL_ARG(a) ;
DBL_ARG(sigma) ;
OUTPUT(gsl_ran_gaussian_tail (r, a, sigma));
}
else if (NAME("ugaussian"))
{
ARGS(0, "unit gaussian, no parameters required");
OUTPUT(gsl_ran_ugaussian (r));
}
else if (NAME("ugaussian-tail"))
{
ARGS(1, "a = lower limit");
DBL_ARG(a) ;
OUTPUT(gsl_ran_ugaussian_tail (r, a));
}
else if (NAME("bivariate-gaussian"))
{
ARGS(3, "sigmax = x std.dev., sigmay = y std.dev., rho = correlation");
DBL_ARG(sigmax) ;
DBL_ARG(sigmay) ;
DBL_ARG(rho) ;
OUTPUT2(gsl_ran_bivariate_gaussian (r, sigmax, sigmay, rho, &x, &y),
x, y);
}
else if (NAME("dir-2d"))
{
OUTPUT2(gsl_ran_dir_2d (r, &x, &y), x, y);
}
else if (NAME("dir-3d"))
{
OUTPUT3(gsl_ran_dir_3d (r, &x, &y, &z), x, y, z);
}
else if (NAME("dir-nd"))
{
double *xarr;
ARGS(1, "n1 = number of dimensions of hypersphere");
INT_ARG(n1) ;
xarr = (double *)malloc(n1*sizeof(double));
for(i = 0; i < n; i++) {
gsl_ran_dir_nd (r, n1, xarr) ;
for (j = 0; j < n1; j++) {
if (j) putchar(' ');
printf("%g", xarr[j]) ;
}
putchar('\n');
} ;
free(xarr);
}
else if (NAME("geometric"))
{
ARGS(1, "p = bernoulli trial probability of success");
DBL_ARG(p) ;
INT_OUTPUT(gsl_ran_geometric (r, p));
}
else if (NAME("gumbel1"))
{
ARGS(2, "a = order, b = scale parameter");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_gumbel1 (r, a, b));
}
else if (NAME("gumbel2"))
{
ARGS(2, "a = order, b = scale parameter");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_gumbel2 (r, a, b));
}
else if (NAME("hypergeometric"))
{
ARGS(3, "n1 = tagged population, n2 = untagged population, t = number of trials");
INT_ARG(n1) ;
INT_ARG(n2) ;
INT_ARG(t) ;
INT_OUTPUT(gsl_ran_hypergeometric (r, n1, n2, t));
}
else if (NAME("laplace"))
{
ARGS(1, "a = scale parameter");
DBL_ARG(a) ;
OUTPUT(gsl_ran_laplace (r, a));
}
else if (NAME("landau"))
{
ARGS(0, "no arguments required");
OUTPUT(gsl_ran_landau (r));
}
else if (NAME("levy"))
{
ARGS(2, "c = scale, a = power (1=cauchy, 2=gaussian)");
DBL_ARG(c) ;
DBL_ARG(a) ;
OUTPUT(gsl_ran_levy (r, c, a));
}
else if (NAME("levy-skew"))
{
ARGS(3, "c = scale, a = power (1=cauchy, 2=gaussian), b = skew");
DBL_ARG(c) ;
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_levy_skew (r, c, a, b));
}
else if (NAME("logarithmic"))
{
ARGS(1, "p = probability");
DBL_ARG(p) ;
INT_OUTPUT(gsl_ran_logarithmic (r, p));
}
else if (NAME("logistic"))
{
ARGS(1, "a = scale parameter");
DBL_ARG(a) ;
OUTPUT(gsl_ran_logistic (r, a));
}
else if (NAME("lognormal"))
{
ARGS(2, "zeta = location parameter, sigma = scale parameter");
DBL_ARG(zeta) ;
DBL_ARG(sigma) ;
OUTPUT(gsl_ran_lognormal (r, zeta, sigma));
}
else if (NAME("negative-binomial"))
{
ARGS(2, "p = probability, a = order");
DBL_ARG(p) ;
DBL_ARG(a) ;
INT_OUTPUT(gsl_ran_negative_binomial (r, p, a));
}
else if (NAME("pareto"))
{
ARGS(2, "a = power, b = scale parameter");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_pareto (r, a, b));
}
else if (NAME("pascal"))
{
ARGS(2, "p = probability, n = order (integer)");
DBL_ARG(p) ;
INT_ARG(N) ;
INT_OUTPUT(gsl_ran_pascal (r, p, N));
}
else if (NAME("poisson"))
{
ARGS(1, "mu = scale parameter");
DBL_ARG(mu) ;
INT_OUTPUT(gsl_ran_poisson (r, mu));
}
else if (NAME("rayleigh"))
{
ARGS(1, "sigma = scale parameter");
DBL_ARG(sigma) ;
OUTPUT(gsl_ran_rayleigh (r, sigma));
}
else if (NAME("rayleigh-tail"))
{
ARGS(2, "a = lower limit, sigma = scale parameter");
DBL_ARG(a) ;
DBL_ARG(sigma) ;
OUTPUT(gsl_ran_rayleigh_tail (r, a, sigma));
}
else if (NAME("tdist"))
{
ARGS(1, "nu = degrees of freedom");
DBL_ARG(nu) ;
OUTPUT(gsl_ran_tdist (r, nu));
}
else if (NAME("weibull"))
{
ARGS(2, "a = scale parameter, b = exponent");
DBL_ARG(a) ;
DBL_ARG(b) ;
OUTPUT(gsl_ran_weibull (r, a, b));
}
else
{
fprintf(stderr,"Error: unrecognized distribution: %s\n", name) ;
}
return 0 ;
}
double
test_laplace (void)
{
return gsl_ran_laplace (r_global, 2.75);
}
double
gsl_ran_exppow (const gsl_rng * r, const double a, const double b)
{
if (b < 1 || b > 4)
{
double u = gsl_rng_uniform (r);
double v = gsl_ran_gamma (r, 1 / b, 1.0);
double z = a * pow (v, 1 / b);
if (u > 0.5)
{
return z;
}
else
{
return -z;
}
}
else if (b == 1)
{
/* Laplace distribution */
return gsl_ran_laplace (r, a);
}
else if (b < 2)
{
/* Use laplace distribution for rejection method, from Tadikamalla */
double x, h, u;
double B = pow (1 / b, 1 / b);
do
{
x = gsl_ran_laplace (r, B);
u = gsl_rng_uniform_pos (r);
h = -pow (fabs (x), b) + fabs (x) / B - 1 + (1 / b);
}
while (log (u) > h);
return a * x;
}
else if (b == 2)
{
/* Gaussian distribution */
return gsl_ran_gaussian (r, a / sqrt (2.0));
}
else
{
/* Use gaussian for rejection method, from Tadikamalla */
double x, h, u;
double B = pow (1 / b, 1 / b);
do
{
x = gsl_ran_gaussian (r, B);
u = gsl_rng_uniform_pos (r);
h = -pow (fabs (x), b) + (x * x) / (2 * B * B) + (1 / b) - 0.5;
}
while (log (u) > h);
return a * x;
}
}