* @brief Tells xbt/random to use the ad-hoc distribution implementation.
*/
void set_implem_xbt();
+
/**
* @brief Tells xbt/random to use the standard library distribution implementation.
*/
void set_implem_std();
+
/**
* @brief Sets the seed of the Mersenne-Twister RNG
*/
* @param max Maximum value
*/
int uniform_int(int min, int max);
+
/**
* @brief Draws a real number uniformly between min and max included
*
* @param max Maximum value
*/
double uniform_real(double min, double max);
+
/**
* @brief Draws a real number according to the given exponential distribution
*
* @param lambda Parameter of the exponential law
*/
double exponential(double lambda);
+
/**
* @brief Draws a real number according to the given normal distribution
*
if (rng_implem == XBT_RNG_std) {
std::uniform_int_distribution<> dist(min, max);
return dist(mt19937_gen);
- }
+ }
unsigned long range = max - min + 1;
unsigned long value = mt19937_gen();
+ xbt_assert(min <= max,
+ "The minimum value for the uniform integer distribution must not be greater than the maximum value");
xbt_assert(range > 0, "Overflow in the uniform integer distribution, please use a smaller range.");
- xbt_assert(
- min <= max,
- "The maximum value for the uniform integer distribution must be greater than or equal to the minimum value");
- while (value >= mt19937_gen.max() - mt19937_gen.max() % range) {
+ while (value >= decltype(mt19937_gen)::max() - decltype(mt19937_gen)::max() % range) {
value = mt19937_gen();
}
return value % range + min;
if (rng_implem == XBT_RNG_std) {
std::uniform_real_distribution<> dist(min, max);
return dist(mt19937_gen);
- }
+ }
// This reuses Boost's uniform real distribution ideas
- unsigned long numerator = mt19937_gen() - mt19937_gen.min();
- unsigned long divisor = mt19937_gen.max() - mt19937_gen.min();
+ constexpr unsigned long divisor = decltype(mt19937_gen)::max() - decltype(mt19937_gen)::min();
+ unsigned long numerator = mt19937_gen() - decltype(mt19937_gen)::min();
return min + (max - min) * numerator / divisor;
}
if (rng_implem == XBT_RNG_std) {
std::exponential_distribution<> dist(lambda);
return dist(mt19937_gen);
- }
+ }
- return -1 / lambda * log(uniform_real(0, 1));
+ return -1.0 / lambda * log(uniform_real(0.0, 1.0));
}
double normal(double mean, double sd)
return dist(mt19937_gen);
}
- double u1 = 0;
+ double u1 = 0.0;
while (u1 < std::numeric_limits<double>::min()) {
- u1 = uniform_real(0, 1);
+ u1 = uniform_real(0.0, 1.0);
}
- double u2 = uniform_real(0, 1);
- double z0 = sqrt(-2.0 * log(u1)) * cos(2 * M_PI * u2);
+ double u2 = uniform_real(0.0, 1.0);
+ double z0 = sqrt(-2.0 * log(u1)) * cos(2.0 * M_PI * u2);
return z0 * sd + mean;
}