using System;
using static System.Math;
using static System.Console;
class main{
static void Main(){
	vector c = new vector("1 1");
	int n=c.size;
	matrix A = new matrix(n,n);
	var rnd=new System.Random(1);
	for(int i=0;i<n;i++)
	for(int j=0;j<n;j++)A[i,j]=2*(rnd.NextDouble()-0.5);
	int ncalls=0;
	Func<vector,double> f = (z)=>{
		ncalls++;
		return ( A*(z-c) ).norm();
		};
	double eps=1e-4;
	vector p = new vector("2 2");
	p.print("broyden:\n start point:");
	int nsteps = qnewton.broyden(f,ref p,eps);
	WriteLine($"nsteps={nsteps}");
	p.print("x_min= ");
	Write($"f(x_min)={f(p)}\n");
	WriteLine($"eps            = {eps}");
	vector g=qnewton.gradient(f,p);
	WriteLine($"gradient(f(x_min)).norm() = {g.norm()}");
	if(g.norm()<eps)WriteLine("test passed");
	else                        WriteLine("test failed");

}
}