Struct statrs::distribution::DiscreteUniform

pub struct DiscreteUniform { /* fields omitted */ }

Implements the Discrete Uniform distribution

Examples

use statrs::distribution::{DiscreteUniform, Discrete};
use statrs::statistics::Distribution;

let n = DiscreteUniform::new(0, 5).unwrap();
assert_eq!(n.mean().unwrap(), 2.5);
assert_eq!(n.pmf(3), 1.0 / 6.0);

Implementations

impl DiscreteUniform

pub fn new(min: i64, max: i64) -> Result<DiscreteUniform>

Constructs a new discrete uniform distribution with a minimum value of min and a maximum value of max.

Errors

Returns an error if max < min

Examples

use statrs::distribution::DiscreteUniform;

let mut result = DiscreteUniform::new(0, 5);
assert!(result.is_ok());

result = DiscreteUniform::new(5, 0);
assert!(result.is_err());

Trait Implementations

impl Clone for DiscreteUniform

fn clone(&self) -> DiscreteUniform

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DiscreteUniform

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Discrete<i64, f64> for DiscreteUniform

fn pmf(&self, x: i64) -> f64

Calculates the probability mass function for the discrete uniform distribution at x

Remarks

Returns 0.0 if x is not in [min, max]

Formula

1 / (max - min + 1)

fn ln_pmf(&self, x: i64) -> f64

Calculates the log probability mass function for the discrete uniform distribution at x

Remarks

Returns f64::NEG_INFINITY if x is not in [min, max]

Formula

ln(1 / (max - min + 1))

impl DiscreteCDF<i64, f64> for DiscreteUniform

fn cdf(&self, x: i64) -> f64

Calculates the cumulative distribution function for the discrete uniform distribution at x

Formula

(floor(x) - min + 1) / (max - min + 1)

fn inverse_cdf(&self, p: T) -> K

Due to issues with rounding and floating-point accuracy the default implementation may be ill-behaved Specialized inverse cdfs should be used whenever possible.

impl Distribution<f64> for DiscreteUniform

fn mean(&self) -> Option<f64>

Returns the mean of the discrete uniform distribution

Formula

(min + max) / 2

fn variance(&self) -> Option<f64>

Returns the variance of the discrete uniform distribution

Formula

((max - min + 1)^2 - 1) / 12

fn entropy(&self) -> Option<f64>

Returns the entropy of the discrete uniform distribution

Formula

ln(max - min + 1)

fn skewness(&self) -> Option<f64>

Returns the skewness of the discrete uniform distribution

Formula

0

fn std_dev(&self) -> Option<T>

Returns the standard deviation, if it exists.

impl Distribution<f64> for DiscreteUniform

fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> f64

Generate a random value of T, using rng as the source of randomness.

fn sample_iter<R>(self, rng: R) -> DistIter<Self, R, T> where
    R: Rng, 

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

impl Max<i64> for DiscreteUniform

fn max(&self) -> i64

Returns the maximum value in the domain of the discrete uniform distribution

Remarks

This is the same value as the maximum passed into the constructor

impl Median<f64> for DiscreteUniform

fn median(&self) -> f64

Returns the median of the discrete uniform distribution

Formula

(max + min) / 2

impl Min<i64> for DiscreteUniform

fn min(&self) -> i64

Returns the minimum value in the domain of the discrete uniform distribution

Remarks

This is the same value as the minimum passed into the constructor

impl Mode<Option<i64>> for DiscreteUniform

fn mode(&self) -> Option<i64>

Returns the mode for the discrete uniform distribution

Remarks

Since every element has an equal probability, mode simply returns the middle element

Formula

N/A // (max + min) / 2 for the middle element

impl PartialEq<DiscreteUniform> for DiscreteUniform

fn eq(&self, other: &DiscreteUniform) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &DiscreteUniform) -> bool

This method tests for !=.

impl Copy for DiscreteUniform

impl StructuralPartialEq for DiscreteUniform