furlong

n. a unit of distance equal to 220 yards

furlong is a zero dependency Node and Javascript library for computing pairwise distance metrics writting in Typescript.

Installation

npm install furlong --save

Usage

furlong can be used with Node or with plain Javascript; it has no external dependencies. To use with Node, simply require it:

const { furlong } = require('furlong')

To use in Javascript, just import it:

import { furlong } from 'furlong'

Pairwise distance functions are computed using a distance method. furlong provides several built-in distance functions and also supports user defined functions. The provided distance functions include:

• Euclidean distance
• Manhattan (Taxicab) distance
• Chebyshev distance
• Bray Curtis distance
• Canberra distance
• Hamming distance

>>> furlong('euclidean').distance([0,0,0],[0,0,100])
100

Accessor functions can also be used for more complex data structures:

>>> const distanceFunc = furlong('chebyshev')
                     .x(d => d.foo)
                     .y(d => d.bar)

>>> const vectorA = [{'foo': 12},{'foo': 7},{'foo': 0}]
>>> const vectorB = [{'bar': 6},{'bar': 32},{'bar': 27}]
>>> distanceFunc
      .distance(vectorA, vectorB)
      .toFixed(2)
27

Custom distance functions can be used with furlong's accessors as well:

>>> const customDistanceFunc = (v1, v2) => 0
>>> furlong('hamming')
    .func(customDistanceFunc)
    .distance([0,0],[1,1])
0

Testing

• Using npm:
  npm test

Release History

• 0.1.0 Initial release
• 0.2.0 Ported library to Typescript