Vector = function Vector( x, y ) {

        // enforce instantiation
        if ( !(this instanceof Vector) ){

            return new Vector( x, y );
        }

        // arrays to store values
        // x = _[0]
        // y = _[1]
        // norm = _[3]
        // normsq = _[4]

        /** internal
         * Physics.vector#_
         *
         * Private storage array for data.
         *
         * Do not access this directly. Private. Keep out.
         **/
        if (typedArrays){
            this._ = new Float64Array(5);
        } else {
            this._ = [];
        }

        if (x && (x.x !== undefined || x._ && x._.length)){

            this.clone( x );

        } else {

            this.recalc = true; //whether or not recalculate norms
            this.set( x, y );
        }
    }
new Physics.vector( x, y )
new Physics.vector( vect )
- x (Number): The x coordinate
- y (Number): The y coordinate
- vect (Vectorish): A vector-like object to clone

Vector Constructor.