Mathware

A small compact library for algebra and vector manipulation for Node.js. Tries to be small and have no dependencies.

Note

The library is permissive on purpose. It won't check a v2 vs a v3 sum. It is on purpose to avoid the performance penalty hit.

I'll add soon JSDoc so at least you have those checks upfront.

Download

Install via npm:

npm install mathware

then require it:

const mw = require('mathware');

Examples

Create vector with new (defaults to empty)

var v2 = new mw.vec2(); // Vec2 {x:0 , y:0 }
var v3 = new mw.vec3(); // Vec3 {x:0 , y:0, z:0}
var v4 = new mw.vec4(); // Vec3 {x:0 , y:0, z:0, w:1 }

You can pass the initial values

var v3 = new mw.vec3(1.0, 2.0, 3.0); // Vec3 {x:1 , y:2, z:3 }

You can also create with a shorthand

var v3 = mw.v3(1.0, 2.0, 3.0); // Vec3 {x:1 , y:2, z:3 }

Documentation

You can select the vector modules out for your need

const vec2 = require('mathware').vec2;
var v = new vec2();

In-place methods

If you want to alter a vector in place, you call the method on the object directly

var v1 = mw.v3(1,2,3);
var v2 = mw.v3(2,1,0);
v1.add(v2);  // v1 { x:3, y:3, z:3 }

If you want instead to make a new copy, using the static method

var v1 = mw.v3(1,1,1);
var v2 = mw.v3(0,0,1);
var aNewVector = mw.vec3.add(v1, v2); 
// v1{ 1,1,1} , v2{ 0,0, 1}, aNewVector {1,1,2}

Chaining

All the in place methods that should return a vector, will return this

var v1 = mw.v2(1,2)
        .scalarMultiply(2)
        .add( mw.v2(-2, -2) );
//v1 { x: 0, y : 2 }

Instance Methods

constructor

add(v) Adds a vector

sub Subtracts a vector

scalarMultiply(a) Multiplies every component by the scalar a

dot(v)

Dot product of the two vectors Remember that is equal to module(a) * module(b) * cos(alpha)

cross(v)

The cross product between the current vector and the param vector

midpoint(v)

Returs a new vector that is mid way between the current and v

squaredLenght

length

distance(v)

squaredDistance(v)

normalize normalizes the vector in place

zero sets the current vector components to zero

set sets the components passed element by element

toArray

returns an array in the format [x,y,z]

fromArray(ary) sets the values ary[a0,a1,a2] -> v{ x:a0, y:a1, z:a2}

equal(v) Compares the two vectors and returns true if equal

Static Methods

There is a static method version for every instance method that return a vector. also

centroid(ary)

Returns the centroid of an array of vectors

//Define a square of 10x10
let v1 = mw.v2(0,0);
let v2 = mw.v2(10,10);
let v3 = mw.v2(0,10);
let v4 = mw.v2(10,0);
console.dir(mw.vec2.centroid([v1,v2,v3,v4])); // {x:5, y:5}