ndarray-distance

Computes the Lp distance between two ndarrays. Works both in node.js and in browserify.

Example

var distance = require("ndarray-distance")
var ndarray = require("ndarray")

//Create two arrays
var a = ndarray([1, 2, 3, 4, 5])
var b = ndarray([0, 2, 3, 10, 6])


//First compute sum of squared distances
var l2Dist = distance(a, b)

//Can also compute l1 distance (absolute difference)
var l1Dist = distance(a, b, 1)

//And maximum distance
var linfDist = distance(a, b, Infinity)

//And any other Lp distance as well
var l3Dist = distance(a, b, 3)

Install

Install using npm:

npm install ndarray-distance

API

`require("ndarray-distance")(a, b[, p])`

Computes the Lp distance between two ndarrays a and b. That is,

dist(a,b,p) = ( sum |a[i] - b[i]|^p )^(1/p)

Note that here a and b do not have to be vectors and can be images or volumes.

a and b are both ndarrays with the same shape
p is a parameter that determines the exponent of the metric. The default value is p=2

Special values of p include:

p=0 which counts the number of entries where a and b differ
p=1 which is the absolute difference between a and b
p=2 which is the ordinary Euclidean sum of squared differences
p=Infinity which is the maximum absolute difference between a and b

Returns The Lp distance between a and b

License

Current Tags

1.0.0 ... latest (6 years ago)

2 Versions

1.0.0 ... 6 years ago
0.0.0 ... 7 years ago