#include<stdlib.h>
#include<stddef.h>
#include<stdio.h>
#include<math.h>

#include "nr.h"
#include "nrutil.h"

#define NDIM 2

float func(float x[])
{
	int i;
	float f=0.0;

	f = (x[1]-1.0)*(x[1]-1.0) + 100*(x[2]-3.0)*(x[2]-3.0);
//	f = pow(x[1]-x[2], 2) + pow(x[1]+x[2], 20);
	return f;
}

void dfunc(float x[], float d[])
{
	d[1] = 2.0*(x[1]-1.0);
	d[2] = 200.0*(x[2]-3.0);
//	d[1] = 2*(x[1]-x[2]) + 20*pow(x[1]+x[2], 19);
//	d[2] = 2*(x[2]-x[1]) + 20*pow(x[1]+x[2], 19);
}

int main(void)
{
	int i,j,iter;
	float fret,sr2,x,*p,*xi;

	p=vector(1,NDIM);
	xi=vector(1,NDIM);
	printf("\nMinimum of a 2-d quadratic centered\n");
	printf("at (1.0,3.0). \n");
	printf("%9s %12s %12s \n","x","y","functin value");

	frprmn(p, NDIM, 1.0e-3, &iter, &fret, func, dfunc);

	printf("iteration = %i \n", iter);

	free_vector(xi,1,NDIM);
	free_vector(p,1,NDIM);
	return 0;
}