int test_defaults_dp() {
dgs_disc_gauss_dp_t *self;
self = dgs_disc_gauss_dp_init(3.0, 0, 6, DGS_DISC_GAUSS_DEFAULT);
if (self->algorithm != DGS_DISC_GAUSS_UNIFORM_TABLE)
dgs_die("automatic choice of uniform table algorithm failed (%d)", self->algorithm);
dgs_disc_gauss_dp_clear(self);
self = dgs_disc_gauss_dp_init(3.0, 0, 1<<10, DGS_DISC_GAUSS_DEFAULT);
if (self->algorithm != DGS_DISC_GAUSS_UNIFORM_TABLE)
dgs_die("automatic choice of uniform table algorithm failed (%d)", self->algorithm);
dgs_disc_gauss_dp_clear(self);
self = dgs_disc_gauss_dp_init(3.0, 0, 1<<14, DGS_DISC_GAUSS_DEFAULT);
if (self->algorithm != DGS_DISC_GAUSS_UNIFORM_LOGTABLE)
dgs_die("automatic choice of uniform table algorithm failed (%d)", self->algorithm);
dgs_disc_gauss_dp_clear(self);
double sigma2 = sqrt(1.0/(2*log(2.0)));
self = dgs_disc_gauss_dp_init(1024*sigma2, 0, 6, DGS_DISC_GAUSS_DEFAULT);
if (self->algorithm != DGS_DISC_GAUSS_SIGMA2_LOGTABLE)
dgs_die("automatic choice of uniform table algorithm failed (%d)", self->algorithm);
dgs_disc_gauss_dp_clear(self);
printf("passed\n");
return 0;
}
double run_dp(double sigma, double c, int tau, dgs_disc_gauss_alg_t alg, size_t ntrials, unsigned long long *t) {
double variance = 0.0;
gmp_randstate_t state;
gmp_randinit_default(state);
dgs_disc_gauss_dp_t *gen = dgs_disc_gauss_dp_init(sigma, c, tau, alg);
*t = walltime(0);
for(size_t i=0; i<ntrials; i++) {
long r = gen->call(gen);
variance += ((double)r)*((double)r);
}
*t = walltime(*t);
dgs_disc_gauss_dp_clear(gen);
gmp_randclear(state);
variance /= ntrials;
return sqrt(variance);
}
dgs_disc_gauss_dp_t *dgs_disc_gauss_dp_init(double sigma, double c, size_t tau, dgs_disc_gauss_alg_t algorithm) {
if (sigma <= 0.0)
dgs_die("sigma must be > 0");
if (tau == 0)
dgs_die("tau must be > 0");
size_t upper_bound;
dgs_disc_gauss_dp_t *self = (dgs_disc_gauss_dp_t*)calloc(sizeof(dgs_disc_gauss_dp_t),1);
if (!self) dgs_die("out of memory");
self->sigma = sigma;
self->c = c;
self->c_z = (long)c;
self->c_r = self->c - ((double)self->c_z);
self->tau = tau;
switch(algorithm) {
case DGS_DISC_GAUSS_UNIFORM_ONLINE:
self->call = dgs_disc_gauss_dp_call_uniform_online;
upper_bound = ceil(self->sigma*tau) + 1;
self->upper_bound = upper_bound;
self->upper_bound_minus_one = upper_bound - 1;
self->two_upper_bound_minus_one = 2*upper_bound - 1;
self->f = -1.0/(2.0*(self->sigma*self->sigma));
break;
case DGS_DISC_GAUSS_UNIFORM_TABLE:
self->call = dgs_disc_gauss_dp_call_uniform_table;
upper_bound = ceil(self->sigma*tau) + 1;
self->upper_bound = upper_bound;
self->upper_bound_minus_one = upper_bound - 1;
self->two_upper_bound_minus_one = 2*upper_bound - 1;
self->B = dgs_bern_uniform_init(0);
self->f = -1.0/(2.0*(sigma*sigma));
if(self->c_r == 0) {
self->call = dgs_disc_gauss_dp_call_uniform_table;
self->rho = (double*)malloc(sizeof(double)*self->upper_bound);
if (!self->rho) {
dgs_disc_gauss_dp_clear(self);
dgs_die("out of memory");
}
for(unsigned long x=0; x<self->upper_bound; x++) {
self->rho[x] = exp( (((double)x) - self->c_r) * (((double)x) - self->c_r) * self->f);
}
self->rho[0]/= 2.0;
} else {
self->call = dgs_disc_gauss_dp_call_uniform_table_offset;
self->rho = (double*)malloc(sizeof(double)*self->two_upper_bound_minus_one);
if (!self->rho) {
dgs_disc_gauss_dp_clear(self);
dgs_die("out of memory");
}
long absmax = self->upper_bound_minus_one;
for(long x=-absmax; x<=absmax; x++) {
self->rho[x+self->upper_bound_minus_one] = exp( (((double)x) - self->c_r) * (((double)x) - self->c_r) * self->f);
}
}
break;
case DGS_DISC_GAUSS_UNIFORM_LOGTABLE:
self->call = dgs_disc_gauss_dp_call_uniform_logtable;
if (fabs(self->c_r) > DGS_DISC_GAUSS_INTEGER_CUTOFF) {
dgs_disc_gauss_dp_clear(self);
dgs_die("algorithm DGS_DISC_GAUSS_UNIFORM_LOGTABLE requires c%1 == 0");
}
upper_bound = ceil(self->sigma*tau) + 1;
self->upper_bound = upper_bound;
self->upper_bound_minus_one = upper_bound - 1;
self->two_upper_bound_minus_one = 2*upper_bound - 1;
_dgs_disc_gauss_dp_init_bexp(self, self->sigma, self->upper_bound);
break;
case DGS_DISC_GAUSS_SIGMA2_LOGTABLE: {
self->call = dgs_disc_gauss_dp_call_sigma2_logtable;
if (fabs(self->c_r) > DGS_DISC_GAUSS_INTEGER_CUTOFF) {
dgs_disc_gauss_dp_clear(self);
dgs_die("algorithm DGS_DISC_GAUSS_SIGMA2_LOGTABLE requires c%1 == 0");
}
double sigma2 = sqrt(1.0/(2*log(2.0)));
double k = sigma/sigma2;
self->k = round(k);
self->sigma = self->k * sigma2;
upper_bound = ceil(self->sigma*tau) + 1;
self->upper_bound = upper_bound;
self->upper_bound_minus_one = upper_bound - 1;
self->two_upper_bound_minus_one = 2*upper_bound - 1;
_dgs_disc_gauss_dp_init_bexp(self, self->sigma, self->upper_bound);
self->B = dgs_bern_uniform_init(0);
self->D2 = dgs_disc_gauss_sigma2p_init();
break;
}
default:
dgs_disc_gauss_dp_clear(self);
dgs_die("unknown algorithm %d", algorithm);
}
return self;
}