//      e04dg Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
using System.IO;
namespace NagDotNetExamples
{
  public class E04DGE
  {
    static string datafile = "ExampleData/e04dge.d";
    // as a command line argument. It defaults to the named file specified below otherwise.
    //
    static void Main(String[] args)
    {
      if (args.Length == 1)
      {
        datafile = args[0];
      }
      StartExample();
    }
    public static void StartExample()
    {
      E04.E04DG_OBJFUN objfunE04DG = new E04.E04DG_OBJFUN(objfun);
      try
      {
        DataReader sr = new DataReader(datafile);
      double objf;
      int i,  ifail,  iter,  n; Console.WriteLine("e04dg Example Program Results");
      //      Skip heading in data file
      sr.Reset();
      sr.Reset();
      n = int.Parse(sr.Next());
      double[] objgrd = new double[n];
      double[] x = new double[n]; 
      //
      //         Read x from data file
      //
      sr.Reset();
      for (i = 1; i <= n; i++)
      {
        x[i - 1] = double.Parse(sr.Next(), CultureInfo.InvariantCulture);
      }
      //
      //         Initialise E04.e04dg
      //
      E04.e04dgOptions options = new E04.e04dgOptions();
      //
      //            Solve the problem
      //
      options.Set("List");
      options.Set("Print level = 10");
      E04.e04dg(n, objfunE04DG, out iter, out objf, objgrd, x, options, out ifail);
      //
      //            Check for error exits
      //
      Console.WriteLine("");
      if ((ifail >= 0) && (ifail < 9))
      {
        Console.WriteLine(" ** e04dg returned with ifail = {0, 3}", ifail);
        Console.WriteLine("");
        Console.WriteLine("  Variable                    Value                Gradient value");
        Console.WriteLine("");
        for (i = 1; i <= n; i++)
        {
          Console.WriteLine("  Varbl  {0,3}        {1,15:g7}        {2,9:g1}", i, x[i - 1], objgrd[i - 1]);
        }
        Console.WriteLine("");
        Console.WriteLine("");
        Console.WriteLine("  Final objective value = {0,15:g7}", objf);
      }
      else
      {
        if (ifail >= (9))
        {
          Console.WriteLine("   ** An input parameter is invalid");
        }
        else if (ifail == -399)
        {
          Console.WriteLine(" ** e04dg returned with ifail = {0, 3}", ifail);
        }
        else
        {
          Console.WriteLine("  MODE < 0 on exit from OBJFUN. Problem abandoned.");
        }
      }
      //
      //
    }
    catch (Exception e)
    {
      Console.WriteLine(e.Message);
      Console.WriteLine( "Exception Raised");
    }
  }
  //
  public static void objfun(ref int mode, int n, double[] x, out double objf,
  double[] objgrd, int nstate)
  {
    //      Routine to evaluate F(x) and its 1st derivatives.
    double one = 1.00e0;
    double two = 2.00e0;
    double four = 4.00e0;
    double expx1,  x1,  x2;
    x1 = x[0];
    x2 = x[1];
    expx1 = Math.Exp(x1);
    objf = expx1 * (four * (x1) * (x1) + two * (x2) * (x2) + four * x1 * x2 + two * x2 + one);
    //
    if (mode == 2)
    {
      objgrd[0] = four * expx1 * (two * x1 + x2) + objf;
      objgrd[1] = two * expx1 * (two * x2 + two * x1 + one);
    }
    //
  }
}
}