采用多项式曲线拟合可以得到系数向量x
A=[5.764 6.286 6.759 7.168 7.408];B=[0.648 1.202 1.832 2.526 3.360];cftool
在工具箱中，选择拟合的数据和拟合类型，
左下角即为数据结果，右边是图像结果。
Coefficients (with 95% confidence bounds): p1 = 0.6459 (-0.3031, 1.595) p2 = -6.936 (-19.45, 5.577) p3 = 19.21 (-21.76, 60.17)
