[][src]Struct rand::distributions::uniform::Uniform

pub struct Uniform<X: SampleUniform> { /* fields omitted */ }

Sample values uniformly between two bounds.

Uniform::new and Uniform::new_inclusive construct a uniform distribution sampling from the given range; these functions may do extra work up front to make sampling of multiple values faster.

When sampling from a constant range, many calculations can happen at compile-time and all methods should be fast; for floating-point ranges and the full range of integer types this should have comparable performance to the Standard distribution.

Steps are taken to avoid bias which might be present in naive implementations; for example rng.gen::<u8>() % 170 samples from the range [0, 169] but is twice as likely to select numbers less than 85 than other values. Further, the implementations here give more weight to the high-bits generated by the RNG than the low bits, since with some RNGs the low-bits are of lower quality than the high bits.

Implementations must sample in [low, high) range for Uniform::new(low, high), i.e., excluding high. In particular care must be taken to ensure that rounding never results values < low or >= high.

Example

use rand::distributions::{Distribution, Uniform};

fn main() {
    let between = Uniform::from(10..10000);
    let mut rng = rand::thread_rng();
    let mut sum = 0;
    for _ in 0..1000 {
        sum += between.sample(&mut rng);
    }
    println!("{}", sum);
}

Methods

impl<X: SampleUniform> Uniform<X>
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Create a new Uniform instance which samples uniformly from the half open range [low, high) (excluding high). Panics if low >= high.

Create a new Uniform instance which samples uniformly from the closed range [low, high] (inclusive). Panics if low > high.

Trait Implementations

impl<X: SampleUniform> Distribution<X> for Uniform<X>
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Important traits for DistIter<'a, D, R, T>

Create an iterator that generates random values of T, using rng as the source of randomness. Read more

impl<X: SampleUniform> From<Range<X>> for Uniform<X>
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impl<X: SampleUniform> From<RangeInclusive<X>> for Uniform<X>
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impl<X: Clone + SampleUniform> Clone for Uniform<X> where
    X::Sampler: Clone
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Performs copy-assignment from source. Read more

impl<X: Copy + SampleUniform> Copy for Uniform<X> where
    X::Sampler: Copy
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impl<X: Debug + SampleUniform> Debug for Uniform<X> where
    X::Sampler: Debug
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Auto Trait Implementations

impl<X> Send for Uniform<X> where
    <X as SampleUniform>::Sampler: Send

impl<X> Sync for Uniform<X> where
    <X as SampleUniform>::Sampler: Sync

Blanket Implementations

impl<T> From for T
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impl<T, U> Into for T where
    U: From<T>, 
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impl<T> ToOwned for T where
    T: Clone
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impl<T, U> TryFrom for T where
    T: From<U>, 
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🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T> Borrow for T where
    T: ?Sized
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impl<T> BorrowMut for T where
    T: ?Sized
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impl<T, U> TryInto for T where
    U: TryFrom<T>, 
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🔬 This is a nightly-only experimental API. (try_from)

The type returned in the event of a conversion error.

impl<T> Any for T where
    T: 'static + ?Sized
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impl<T> FromCast for T
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impl<T, U> Cast for T where
    U: FromCast<T>, 
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impl<T> FromBits for T
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impl<T, U> IntoBits for T where
    U: FromBits<T>, 
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