//      e04hc Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
using System.IO;
namespace NagDotNetExamples
{
  public class E04HCE
  {
    static void Main(String[] args)
    {
      StartExample();
    }
    public static void StartExample()
    {
      E04.E04HC_FUNCT functE04HC = new E04.E04HC_FUNCT(funct);
      try
      {
        double f = 0.0;
        int ifail,  j;
        int n = 4;
        int lw = 3 * n;
        double[] g = new double[n];
        double[] w = new double[lw];
        double[] x = new double[n];
        int[] iw = new int[1];
        Console.WriteLine("e04hc Example Program Results");
        //      Set up an arbitrary point at which to check the 1st derivatives
        x[0] = 1.460e0;
        x[1] = -0.820e0;
        x[2] = 0.570e0;
        x[3] = 1.210e0;
        Console.WriteLine("");
        Console.Write(" {0}", "The test point is");
        for (j = 1; j <= n; j++)
        {
          Console.WriteLine(" " + " {0, 10:f4}", x[j - 1]);
        }
        Console.WriteLine(" ");
        //
        E04.e04hc(n, functE04HC, x, out f, g, out ifail);
        //
        Console.WriteLine("");
        if (ifail == 1)
        {
          Console.WriteLine(" {0}", "A parameter is outside its expected range");
        }
        else if (ifail >= 0)
        {
          if (ifail == 0)
          {
            Console.WriteLine(" {0}", "1st derivatives are consistent with function values");
          }
          else
          {
            Console.WriteLine(" {0}", "Probable error in calculation of 1st derivatives");
          }
          Console.WriteLine("");
          Console.WriteLine("  {0}{1,12:e4}", "At the test point, FUNCT gives the function value", f);
          Console.WriteLine(" {0}", "and the 1st derivatives");
          for (j = 1; j <= n; j++)
          {
            Console.Write(" " + " {0, 12:e3}", g[j - 1]);
          }
          Console.WriteLine(" ");
        }
        else
        {
          if (ifail < 0)
          {
            Console.WriteLine("  {0}{1,3}{2}", "IFLAG was set to ", ifail, "in FUNCT");
          }
        }
        //
      }
      catch (Exception e)
      {
        Console.WriteLine(e.Message);
        Console.WriteLine( "Exception Raised");
      }
    }
    //
    public static void funct(ref int iflag, int n, double[] xc, ref double fc,
    double[] gc)
    {
      //      Routine to evaluate objective function and its 1st derivatives.
      fc = 0.0;
      if (iflag != 1)
      {
        fc = ((xc[0] + 10.00e0 * xc[1])) * ((xc[0] + 10.00e0 * xc[1])) + 5.00e0 * ((xc[2] - xc[3])) * ((xc[2] - xc[3])) + Math.Pow((xc[1] - 2.00e0 * xc[2]), 4) + 10.00e0 * Math.Pow((xc[0] - xc[3]), 4);
      }
      if (iflag != 0)
      {
        gc[0] = 2.00e0 * (xc[0] + 10.00e0 * xc[1]) + 40.00e0 * Math.Pow((xc[0] - xc[3]), 3);
        gc[1] = 20.00e0 * (xc[0] + 10.00e0 * xc[1]) + 4.00e0 * Math.Pow((xc[1] - 2.00e0 * xc[2]), 3);
        gc[2] = 10.00e0 * (xc[2] - xc[3]) - 8.00e0 * Math.Pow((xc[1] - 2.00e0 * xc[2]), 3);
        gc[3] = 10.00e0 * (xc[3] - xc[2]) - 40.00e0 * Math.Pow((xc[0] - xc[3]), 3);
      }
    }
  }
}