Struct str_distance::qgram::Jaccard

pub struct Jaccard { /* fields omitted */ }

Represents a Jaccard metric where q is the length of a q-gram fragment.

The distance corresponds to

    1 - |Q(s1, q) ∩ Q(s2, q)| / |Q(s1, q) ∪ Q(s2, q))|

where Q(s, q) denotes the set of q-grams of length n for the str s.

If both inputs are empty a value of 0. is returned. If one input is empty and the other is not, a value of 1. is returned. This avoids a return of f64::NaN for those cases.

Methods

impl Jaccard

pub fn new(q: usize) -> Self

Creates a new [Jaccard] of length q.

Panics

Panics if q is 0.

Trait Implementations

impl Clone for Jaccard

fn clone(&self) -> Jaccard

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Jaccard

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

Formats the value using the given formatter.

impl DistanceMetric for Jaccard

type Dist = f64

Represents the data type in which this distance is evaluated.

fn distance<S, T>(&self, a: S, b: T) -> Self::Dist where
    S: IntoIterator,
    T: IntoIterator,
    <S as IntoIterator>::IntoIter: Clone,
    <T as IntoIterator>::IntoIter: Clone,
    <S as IntoIterator>::Item: PartialEq + PartialEq<<T as IntoIterator>::Item>,
    <T as IntoIterator>::Item: PartialEq, 

Generic implementation of the metric.

fn normalized<S, T>(&self, a: S, b: T) -> f64 where
    S: IntoIterator,
    T: IntoIterator,
    <S as IntoIterator>::IntoIter: Clone,
    <T as IntoIterator>::IntoIter: Clone,
    <S as IntoIterator>::Item: PartialEq + PartialEq<<T as IntoIterator>::Item>,
    <T as IntoIterator>::Item: PartialEq, 

Evaluates the normalized distance between two strings A value of '0.0' corresponds to the "zero distance", both strings are considered equal by means of the metric, whereas a value of '1.0' corresponds to the maximum distance that can exist between the strings.

fn str_distance<S, T>(&self, a: S, b: T) -> Self::Dist where
    S: AsRef<str>,
    T: AsRef<str>, 

Evaluates the distance between two str.

fn str_normalized<S, T>(&self, a: S, b: T) -> f64 where
    S: AsRef<str>,
    T: AsRef<str>, 

Convenience normalization for str types.