using System;
using static System.Math;
using static System.Console;
class main{
static void Main(){
	int calls=0;
	double a=0,b=1,acc=1e-3,eps=1e-3;

	{
	Func<double,double> f=delegate(double x){calls++;return Sqrt(x);};
	WriteLine($"open4: int_{a}^{b} Sqrt(x) dx, acc={acc} eps={eps}");
	double exact=2.0/3;
	double Q=quad.open4(f,a,b,acc,eps);
	double aerr=Abs(Q-exact),tol=acc+eps*Abs(Q);
	Write($"result={Q    :f6}, tolerance={tol :e3}, calls={calls}\n");
	Write($"exact ={exact:f6}, error    ={aerr:e3}, ");
	if(aerr<tol)WriteLine("test passed :)\n");
	else WriteLine("TEST FAILED :(\n");
	}

	{
	Func<double,double> f=delegate(double x){calls++;return 1/Sqrt(x);};
	WriteLine($"open4: int_{a}^{b} 1/Sqrt(x) dx, acc={acc} eps={eps}");
	double exact=2.0;
	double Q=quad.open4(f,a,b,acc,eps);
	double aerr=Abs(Q-exact),tol=acc+eps*Abs(Q);
	Write($"result={Q    :f6}, tolerance={tol :e3}, calls={calls}\n");
	Write($"exact ={exact:f6}, error    ={aerr:e3}, ");
	if(aerr<tol)WriteLine("test passed :)\n");
	else WriteLine("TEST FAILED :(\n");
	}

	{
	calls=0; acc=1e-6; eps=0;
	Func<double,double> f=delegate(double x){calls++;return 4*Sqrt(1-x*x);};
	WriteLine($"open4: int_{a}^{b} 4*Sqrt(1-x^2) dx, acc={acc} eps={eps}");
	double exact=PI;
	double Q=quad.open4(f,a,b,acc,eps,limit:100);
	double aerr=Abs(Q-exact),tol=acc+eps*Abs(Q);
	Write($"result={Q    }, tolerance={tol :e3}, calls={calls}\n");
	Write($"exact ={exact}, error    ={aerr:e3}, ");
	if(aerr<tol)WriteLine("test passed :)\n");
	else WriteLine("TEST FAILED :(\n");
	}

	{
	calls=0; acc=1e-6; eps=0;
	Func<double,double> f=delegate(double x){calls++;return 4*Sqrt(1-x*x);};
	WriteLine($"open8av: int_{a}^{b} 4*Sqrt(1-x^2) dx, acc={acc} eps={eps}");
	double exact=PI;
	double Q=quad.o8av(f,a,b,acc,eps);
	double aerr=Abs(Q-exact),tol=acc+eps*Abs(Q);
	Write($"result={Q    }, tolerance={tol :e3}, calls={calls}\n");
	Write($"exact ={exact}, error    ={aerr:e3}, ");
	if(aerr<tol)WriteLine("test passed :)\n");
	else WriteLine("TEST FAILED :(\n");
	}

}
}