Natural gradient is a new optimization way that is proposed in a special space ? riemannian space . the parameter space in blind source separation is riemannian space . natural gradient has many better characters compared with normal gradient 自然梯度下降法是一种新的最优化方法，自然梯度下降法是在黎曼空间下提出的，自然梯度相比于标准梯度有很多优点。
