//      c06gb Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
namespace NagDotNetExamples
{
  public class C06GBE
  {
    static string datafile = "ExampleData/c06gbe.d";
    static void Main(String[] args)
    {
      if (args.Length == 1)
      {
        datafile = args[0];
      }
      StartExample();
    }
    public static void StartExample()
    {
      try
      {
        DataReader sr = new DataReader(datafile);
        int j,  n,  n2,  nj;
        int ifail;
        Console.WriteLine("c06gb Example Program Results");
        //      Skip heading in data file
        sr.Reset();
        try
        {
          while (true)
          {
            sr.Reset();
            n = int.Parse(sr.Next());
            if (n >= 1)
            {
              double[] a = new double[n];
              double[] b = new double[n];
              double[] x = new double[n];
              for (j = 0 ; j <= n - 1 ; j++)
              {
                sr.Reset();
                x[j - 0] = double.Parse(sr.Next(), CultureInfo.InvariantCulture);
              }
              // 
              C06.c06ea(x, n, out ifail);
              if (ifail == 0)
              {
                C06.c06gb(x, n, out ifail);
                // 
                Console.WriteLine("");
                Console.WriteLine(" {0}","Components of inverse discrete Fourier transform");
                Console.WriteLine("");
                Console.WriteLine(" {0}","           Real      Imag");
                Console.WriteLine("");
                a[0] = x[0];
                b[0] = 0.00e0;
                n2 = (n - 1) / 2;
                for (j = 1 ; j <= n2 ; j++)
                {
                  nj = n - j;
                  a[j - 0] = x[j - 0];
                  a[nj - 0] = x[j - 0];
                  b[j - 0] = x[nj - 0];
                  b[nj - 0] =  -x[nj - 0];
                }
                if (( n % 2 ) == 0)
                {
                  a[n2 + 1 - 0] = x[n2 + 1 - 0];
                  b[n2 + 1 - 0] = 0.00e0;
                }
                for (j = 0 ; j <= n - 1 ; j++)
                {
                  Console.WriteLine("  {0,6}{1,10:f5}{2,10:f5}",j,a[j - 0],b[j - 0]);
                }
              }
              else
              {
                Console.WriteLine("");
                Console.WriteLine(" ** c06ea returned with ifail = {0, 3}", ifail);
              }
            }
            else
            {
              Console.WriteLine(" {0}","Invalid value of N");
            }
          }
        }
        catch
        {
        }
        // 
      }
      catch (Exception e)
      {
        Console.WriteLine(e.Message);
        Console.WriteLine("Exception Raised");
      }
    }
  }
}