public Vector4f subtract(Vector4f vec, Vector4f result) {
        if (result == null) {
            result = new Vector4f();
        }
        result.x = x - vec.x;
        result.y = y - vec.y;
        result.z = z - vec.z;
        result.w = w - vec.w;
        return result;
    }
<code>subtract</code>

@param vec
           the vector to subtract from this
@param result
           the vector to store the result in
@return result
jme3-core/src/main/java/com/jme3/math/Vector4f.java