一个曲线拟合的问题,高手请指点~(回答满意的加至200分!)

来源：百度知道 编辑：UC知道 时间：2024/05/21 23:42:29
各位高手,谁知道怎么把这两个相互对应的数组的曲线给我拟合出来.我采用了最小二乘法但是好象不对，谁知道帮忙给我拟合一下,用C/C++都可以!很急知道帮忙一下~~~小弟感激不尽.写好了，可以发到我的邮箱:duan.gexin@byd.com.cn

double X[21] = {0.00,0.056,0.112,0.168,0.224,0.280,0.336,0.392,0.448,0.504,0.560, 0.616,0.672,0.728,0.784,0.84,0.896,0.952,0.1008,0.1064,1.12}
double Y[21] = {0.00,1.66,3.31,4.96,6.6,8.22,9.82,11.4,12.94,14.43,15.86,17.22,18.5, 19.69,20.79,21.79,22.71,23.53,24.25,24.87,25.4};谢谢拉~~
请问要怎么样才能拟合出我的那条曲线呢?有什么方法呢???
知道的请大家介绍一下~~谢谢拉~~~~~

用Matlab呀最方便了，三条语句就行了
>>x=[0.00,0.056,0.112,0.168,0.224,0.280,0.336,0.392,0.448,0.504,0.560, 0.616,0.672,0.728,0.784,0.84,0.896,0.952,0.1008,0.1064,1.12]
>>y=[0.00,1.66,3.31,4.96,6.6,8.22,9.82,11.4,12.94,14.43,15.86,17.22,18.5, 19.69,20.79,21.79,22.71,23.53,24.25,24.87,25.4]
>>a=polyfit(x,y,20)
a =

1.0e+016 *

Columns 1 through 10

-0.0231 0.2258 -1.0255 2.8708 -5.5471 7.8513 -8.4296 7.0150 -4.5838 2.3680

Columns 11 through 20

-0.9691 0.3134 -0.0795 0.0157 -0.0023 0.0003 -0.0000 0.0000 -0.0000 0.0000

Column 21

-0.0000

a是多项式系数，按降幂排列

polyfit(x,y,n)--最小二乘法曲线拟合函数，x,y是数据点，n是拟合多项式的次数，可根据情况调整。一般N＋1个数据点，用N次多项式来拟合

最小二乘法就是拟合y=kx+b的

我拟合看了一下，这是由于数据中有“飞点”。你要手动处理掉这两个点。
（0.1008，24.25）（0.1064，24.87）
踢除这两点以后的拟合结果为：
y = 24.052x + 1.3588