negate() {

		this.x = - this.x;
		this.y = - this.y;
		this.z = - this.z;
		this.w = - this.w;

		return this;

	}
Inverts this vector - i.e. sets x = -x, y = -y, z = -z, w = -w.

@return {Vector4} A reference to this vector.