在实验读取出数据后，有4个点
x=[213,435,660,883]
y=[31.6,64.3,96.7,128]
公式为
a=0;
b=0.18;
P=7.1;
然后我想先利用4个点作出拟合曲线，再将曲线分成100个离散点，利用复化simpson进行积分函数的计算分量Vi，再讲所有值进行求和得出V。
这是自己写的，发现求出的值不对，在这里求助大神进行解答。
>> clear
>> x=[0.000213,0.000435,0.000660,0.000883]
y=[31.6,64.3,96.7,128]
A=[x'.^3 x'.^2 x' ones(length(x),1) ];
A\y'
x =
1.0e-003 *
0.213000000000000 0.435000000000000 0.660000000000000 0.883000000000000
y =
1.0e+002 *
0.316000000000000 0.643000000000000 0.967000000000000 1.280000000000000
ans =
1.0e+009 *
-1.121341298184747
-0.005909789602774
0.000151493798778
-0.000000000389222
clc;
clear;
format long;
a1=-1.121341298184747e+09
b1=-5.909789602773594e+06
c1=1.514937987783842e+05
d1=-0.389221704902491
a= 0;
b= 0.18;
n= 100;
p=7.1;
syms x;
y1=a1*x^3+b1*x^2+c1*x+d1;
fun= sqrt(diff(y1)/p);
Hfun= @ ComSimpsonR;
A= feval (Hfun,fun,a,b,n)
