org.simmetrics

Interface Distance<T>

Type Parameters:

T - type of the elements compared

All Known Subinterfaces:

ListDistance<E>, StringDistance

All Known Implementing Classes:

BlockDistance, DamerauLevenshtein, EuclideanDistance, Levenshtein

public interface Distance<T>

Measures the unnormalized similarity (distance) between two arbitrary objects of the same type . The measurement results in a non-negative value. A value of zero indicates that the objects are similar.

The distance measure should be consistent with equals such that a.equals(b) => distance(a,b) == 0.0.

The distance measure should be reflexive such that distance(a,a) == 0.0.

The distance measure should be symmetric such that distance(a,b) == distance(b,a).

The distance measure may be transitive such that distance(a, c) ≤ distance(a, b) + distance(b, c)

The distance measure may satisfy the coincidence axiom such that compare(a, b) = 0 if and only if a.equals(b)

Implementations may not modify the arguments. Arguments should be treated as if they were unmodifiable.

See Also:

Wikipedia - Metric

Method Summary

Modifier and Type	Method and Description
float	distance(T a, T b) Measures the distance between a and b.

Method Detail

distance

float distance(T a,
               T b)

Measures the distance between a and b. The measurement results in a non-negative value. A value of 0.0 indicates that a and b are similar.

Parameters:

a - object a to compare

b - object b to compare

Returns:

a non-negative value

Throws:

NullPointerException - when either a or b is null