using System;

using System.Runtime.InteropServices; 

using NagCFunctionsAPI;





public class NagD01Functions

{

  

  public static void nag_1d_quad_gen (NAG_D01AJC_FUN f , double a, double b, 

                                      double epsabs, double epsrel, int max_num_subint,

                                      ref double result, ref double abserr,

                                      ref Nag_QuadProgress qp,

                                      ref string error_message, ref int fail_code)

    {   

      NagError fail = new NagError();

      fail.char_array = new char [512];



      NagFunctions.d01ajc(f, a, b, epsabs, epsrel, max_num_subint, ref result,

                          ref abserr, ref qp, ref fail);     

      string tmpstring = new string(fail.char_array);

      error_message = tmpstring;

      fail_code = fail.code;



    } 

  public static void Main()

    {



      NAG_D01AJC_FUN F = new  NAG_D01AJC_FUN (f);

      Nag_QuadProgress qp =  new  Nag_QuadProgress();

      double a = 0.0;

      double pi = 3.14159265358979323846264338328;

      double b = pi*2.0;

      double epsabs = 0.0;

      double epsrel = 0.0001;

      int max_num_subint = 200;

      double result=0.0;

      double abserr=0.0;

      string message = "";

      int fail_code = 0;

                                   

      nag_1d_quad_gen(F, a, b, epsabs, epsrel, max_num_subint,

                      ref result, ref abserr, ref qp, ref message, ref fail_code);



      if (fail_code != 0)

      {

        Console.WriteLine(message);

      }

      else

      {

        Console.WriteLine("Approximation to the integral = {0, 9:f5}", result);

        Console.WriteLine("Estimate of the absolute error = {0, 9:e2}", abserr);

        Console.WriteLine("Number of function evaluations = {0, 4:d}", qp.fun_count);

        Console.WriteLine("Number of subintervals used = {0, 4:d}", qp.num_subint);

      }

    }

  public static double f(double x)

    {

      double pi = 3.14159265358979323846264338328;

      double retval=0;



      retval =  (x*Math.Sin(x*30.0)/Math.Sqrt(1.0-x*x/(pi*pi*4.0)));

      return retval;

    }

}