说明：   几种matlab求解最小值方法源代码-分别是二次插值求解最小值和内德-米德求解最小值和最速下降法和梯度法，适合新手学习使用
(Several matlab methods for minimum source code- two times interpolation for minimum and ned for minimum Mead and steepest descent method and gradient method, suitable for beginners learning to use )