说明：  数学计算中的矩形域的最小二乘曲面拟合。源自常用算法程序集（C语言描述）第三版(徐士良 ,清华大学出版社)
(Math rectangle in the least squares surface fitting. Assembly from the common algorithm (C language description) Third Edition (XU Shi-liang, Tsinghua University Press))