Overview

A module for working with high-dimensionality vectors (hence "vectors-hd") in JavaScript.

I have successfully used this class in projects requiring:

• vectors with 5,000+ dimensions
• billions of rows of data
• various clustering methods (k-means/medoids, etc.).

Installation

npm install sirrobert-vector-hd

Usage

Creating "degenerate" vectors

Degenerate vectors are vector objects without any dimensionality. They have lots of uses including constructing vectors piecemeal.

var vector = new Vector();

Creating populated vectors

Creating a vector with a pre-existing vector list is easy as well.

var dimensions = {x:238, y:8372, z:18};
var vector = new Vector({coords: dimensions});

Vector inspection

The module provides a set of tools for looking at the vectors. The following list of methods help understand what your vector looks like.

• You can directly examine (or manipulate) a dimension this way:

  var vector = new Vector({coords: {"x": 2, "my-dim":3}});

  vector.coords.x == 2 // true vector.coords['my-dim'] == 4 // true

  vector.coords.x = 1238; // set .x to 1238 vector.coords['my-dim'] = 193 // set .my-dim to 193

  vector.hasDimension('my-dim') // true vector.hasDimension('fake') // false

Object accessors

get #dimensions

get #distanceMethod

set #distanceMethod

Object methods

#add()

#hasDimensions()

#removeDimension()

#removeDimensions()

#addDimension()

#addDimensions()

#reduceTo()

#reduceBy()

#is()

#toString()

#fromString()

#distanceTo()

#randomize()

Class methods

#distance()

#random()

#mean()

#dimensionalHistorgram()

#addDistanceFunction()

Creating random vectors

Random vectors are useful for things like generating clustering seeds. There are two ways to get a random vector.

In order to generate a random vector dimension, you need to give it a scale. Scales are interpreted as origin-centered. That means if you use a scale of 2000, the new value will be randomly selected between -2000 to +2000.

Randomizing an existing vector (in part or in toto)

Take an existing vector and randomize parts of it.

var dimensions = {x:238, y:8372, z:18};
var vector = new Vector({coords: dimensions});

Now randomize the "x" value.

// The new value of 'x' will be from -1000 to +1000
vector.randomize('x', -1000);

You can also randomize multiple dimensions at once.

// Randomize .y and .z between -1500 to +1500.
vector.randomize(['y','z'], 1500);

Getting a new random vector

You can also generate a new, fully random vector with the class method #random().

// Creates a 4D vector with each value from -2500 to 2500
var vector = Vector.random(['x','y','z','a'], 2500);

TO DO

Unit Tests

Right now the random functions are tested only for range validity (and definiedness). These should be enhanced with a distribution test to ensure that we're getting a good distribution within the permitted range.

Documentation

Obviously I need to finish the documentation!

A note on the module namespace (sirrobert-)

The 'sirrobert-' module prefix is a staging namespace for my modules I am testing with a small group of people. It will be moved to a general namespace (for example, the sirrobert- prefix removed).