#include <iostream.h>
#include <math.h>
#include "cramer.h"
void polynomial_regression(float x[], float y[], int nb, float &a, float &b, float &c)
{
	float u[3][3],v[3];
	int i,j;
	for(i=0;i<3;i++)
	{
		for(j=0;j<3;j++)u[i][j]=0;
		v[i]=0;
	}
	for(i=0;i<nb;i++)
	{
		u[0][0] += x[i]*x[i];
		u[0][1] += x[i];
		u[1][0] += pow(x[i],3);
		u[2][0] += pow(x[i],4);
		v[0] += y[i];
		v[1] += x[i]*y[i];
		v[2] += x[i]*x[i]*y[i];
	}
	u[0][2]=nb;
	u[1][1]=u[0][0];
	u[1][2]=u[0][1];
	u[2][1]=u[1][0];
	u[2][2]=u[1][1];

	Cramer(u,v,a,b,c);
}
void main()
{
	float x[15]={1.2, 1.5, 1.8, 2.6, 3.1, 4.3, 4.9, 5.3, 5.7, 6.4, 7.1, 7.6, 8.6, 9.2, 9.8};
	float y[15]={4.5, 5.1, 5.8, 6.7, 7.0, 7.3, 7.6, 7.4, 7.2, 6.9, 6.6, 5.1, 4.5, 3.4, 2.7};
	float a,b,c;
	polynomial_regression(x,y,15, a,b,c);
	cout<<a<<endl<<b<<endl<<c<<endl;
}