Struct rand::distributions::Bernoulli
source · pub struct Bernoulli { /* private fields */ }Expand description
The Bernoulli distribution.
This is a special case of the Binomial distribution where n = 1.
§Example
use rand::distributions::{Bernoulli, Distribution};
let d = Bernoulli::new(0.3).unwrap();
let v = d.sample(&mut rand::thread_rng());
println!("{} is from a Bernoulli distribution", v);§Precision
This Bernoulli distribution uses 64 bits from the RNG (a u64),
so only probabilities that are multiples of 2-64 can be
represented.
Implementations§
source§impl Bernoulli
impl Bernoulli
sourcepub fn new(p: f64) -> Result<Bernoulli, BernoulliError>
pub fn new(p: f64) -> Result<Bernoulli, BernoulliError>
Construct a new Bernoulli with the given probability of success p.
§Precision
For p = 1.0, the resulting distribution will always generate true.
For p = 0.0, the resulting distribution will always generate false.
This method is accurate for any input p in the range [0, 1] which is
a multiple of 2-64. (Note that not all multiples of
2-64 in [0, 1] can be represented as a f64.)
sourcepub fn from_ratio(
numerator: u32,
denominator: u32
) -> Result<Bernoulli, BernoulliError>
pub fn from_ratio( numerator: u32, denominator: u32 ) -> Result<Bernoulli, BernoulliError>
Construct a new Bernoulli with the probability of success of
numerator-in-denominator. I.e. new_ratio(2, 3) will return
a Bernoulli with a 2-in-3 chance, or about 67%, of returning true.
return true. If numerator == 0 it will always return false.
For numerator > denominator and denominator == 0, this returns an
error. Otherwise, for numerator == denominator, samples are always
true; for numerator == 0 samples are always false.