最小二乘法拟合y=ax+b 线性函数

```cpp
#include "stdafx.h"
#include <iostream>
#include <string>
#include <vector>

using namespace std;

class zuixiaoerchengfa
{
public:
	zuixiaoerchengfa(vector<double> x, vector<double> y) {
	

		double t1=0, t2=0, t3=0, t4=0;

		for (int i = 0; i < x.size(); i++)
		{
			t1 += x[i]*x[i];
			t2 += x[i];
			t3 += y[i];
			t4 += x[i] * y[i];
		}

		double a = (t4*x.size() - t2*t3) / (t1*x.size() - t2*t2);

		double b = t3 / x.size() - a*t2 / x.size();
		cout << a  <<" "<< b<<endl;
	
	};
	

private:

};


int main()
{


	vector<double> x = { 1,2,3,4 };
	vector<double> y = { 6,5,7,10 };
	zuixiaoerchengfa zl(x,y);

    return 0;
}