Struct rv::dist::Crp

pub struct Crp { /* fields omitted */ }

Chinese Restaurant Process, a distribution over partitions.

Example

use::rv::prelude::*;

let mut rng = rand::thread_rng();

let crp = Crp::new(1.0, 10).expect("Invalid parameters");
let partition = crp.draw(&mut rng);

assert_eq!(partition.len(), 10);

Implementations

impl Crp

pub fn new(alpha: f64, n: usize) -> Result<Self, CrpError>

Create an empty Crp with parameter alpha

Arguments

• alpha: Discount parameter in (0, Infinity)
• n: the number of items in the partition

pub fn new_unchecked(alpha: f64, n: usize) -> Self

Create a new Crp without checking whether the parametes are valid.

pub fn alpha(&self) -> f64

Get the discount parameter, alpha.

Example

let crp = Crp::new(1.0, 12).unwrap();
assert_eq!(crp.alpha(), 1.0);

pub fn set_alpha(&mut self, alpha: f64) -> Result<(), CrpError>

Set the value of alpha

Example

let mut crp = Crp::new(1.1, 20).unwrap();
assert_eq!(crp.alpha(), 1.1);

crp.set_alpha(2.3).unwrap();
assert_eq!(crp.alpha(), 2.3);

Will error for invalid parameters

assert!(crp.set_alpha(0.5).is_ok());
assert!(crp.set_alpha(0.0).is_err());
assert!(crp.set_alpha(-1.0).is_err());
assert!(crp.set_alpha(std::f64::INFINITY).is_err());
assert!(crp.set_alpha(std::f64::NEG_INFINITY).is_err());
assert!(crp.set_alpha(std::f64::NAN).is_err());

pub fn set_alpha_unchecked(&mut self, alpha: f64)

Set the value of alpha without input validation

pub fn n(&self) -> usize

Get the number of entries in the partition, n.

Example

let crp = Crp::new(1.0, 12).unwrap();
assert_eq!(crp.n(), 12);

pub fn set_n(&mut self, n: usize) -> Result<(), CrpError>

Set the value of n

Example

let mut crp = Crp::new(1.1, 20).unwrap();
assert_eq!(crp.n(), 20);

crp.set_n(11).unwrap();
assert_eq!(crp.n(), 11);

Will error for invalid parameters

assert!(crp.set_n(5).is_ok());
assert!(crp.set_n(1).is_ok());
assert!(crp.set_n(0).is_err());

pub fn set_n_unchecked(&mut self, n: usize)

Set the value of alpha without input validation

Trait Implementations

impl Clone for Crp

fn clone(&self) -> Crp

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Crp

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

Formats the value using the given formatter.

impl Display for Crp

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

Formats the value using the given formatter.

impl<'_> From<&'_ Crp> for String

fn from(crp: &Crp) -> String

Performs the conversion.

impl PartialEq<Crp> for Crp

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

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

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

This method tests for !=.

impl Rv<Partition> for Crp

fn ln_f(&self, x: &Partition) -> f64

Probability function

fn draw<R: Rng>(&self, rng: &mut R) -> Partition

Single draw from the Rv

fn f(&self, x: &X) -> f64

Probability function

fn sample<R: Rng>(&self, n: usize, rng: &mut R) -> Vec<X>

Multiple draws of the Rv

fn sample_stream<'r, R: Rng>(
    &'r self,
    rng: &'r mut R
) -> Box<dyn Iterator<Item = X> + 'r>

Create a never-ending iterator of samples

impl StructuralPartialEq for Crp

impl Support<Partition> for Crp

fn supports(&self, _x: &Partition) -> bool

Returns true if x is in the support of the Rv