//      e04kd Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
using System.IO;
namespace NagDotNetExamples
{
  public class E04KDE
  {
    static void Main(String[] args)
    {
      StartExample();
    }
    public static void StartExample()
    {
      E04.E04HC_FUNCT functE04HC = new E04.E04HC_FUNCT(funct);
      E04.E04KD_FUNCT functE04KD = new E04.E04KD_FUNCT(funct);
      E04.E04KD_MONIT monitE04KD = new E04.E04KD_MONIT(monit);
      try
      {
        double delta,  eta,  f,  stepmx,  xtol;
        int ibound,  ifail,  iprint,  j,  maxcal;
        int n = 4;
        int lh = n * (n - 1) / 2;
        int lw = 7 * n + n * (n - 1) / 2;
        int liw = 2;
        double[] bl = new double[n];
        double[] bu = new double[n];
        double[] g = new double[n];
        double[] hesd = new double[n];
        double[] hesl = new double[lh];
        double[] w = new double[lw];
        double[] x = new double[n];
        int[] istate = new int[n];
        int[] iw = new int[liw];
        Console.Out.Flush();
        Console.WriteLine("e04kd Example Program Results");
        //      Check functE04HC by calling e04hc at an arbitrary point. Since e04hc
        //      only checks the derivatives calculated when iflag = 2, a separate
        //      program should be run before using e04hc or e04kd to check that
        //      functE04HC gives the same values for the gc[j-1] when iflag is set to 1
        //      as when iflag is set to 2.
        x[0] = 1.460e0;
        x[1] = -0.820e0;
        x[2] = 0.570e0;
        x[3] = 1.210e0;
        //
        E04.e04hc(n, functE04HC, x, out f, g, out ifail);
        //
        if (ifail != 0)
        {
          Console.WriteLine("");
          Console.WriteLine(" ** e04hc returned with ifail = {0, 3}", ifail);
          return;
        }
        //
        //      Continue setting parameters for e04kd
        //      Set iprint to 1 to obtain output from monitE04KD at each iteration *
        iprint = -1;
        maxcal = 50 * n;
        eta = 0.50e0;
        //      Set xtol and delta to zero so that e04kd  will use the default
        //      values
        xtol = 0.00e0;
        delta = 0.00e0;
        //      We estimate that the minimum will be within 4 units of the
        //      starting point
        stepmx = 4.00e0;
        ibound = 0;
        bl[0] = 1.00e0;
        bu[0] = 3.00e0;
        bl[1] = -2.00e0;
        bu[1] = 0.00e0;
        //      x[2] is not bounded, so we set bl[2] to a large negative
        //      number and bu[2] to a large positive number
        bl[2] = -1.00e6;
        bu[2] = 1.00e6;
        bl[3] = 1.00e0;
        bu[3] = 3.00e0;
        //      Set up starting point
        x[0] = 3.00e0;
        x[1] = -1.00e0;
        x[2] = 0.00e0;
        x[3] = 1.00e0;
        //
        E04.e04kd(n, functE04KD, monitE04KD, iprint, maxcal, eta, xtol, delta, stepmx, ibound,
        bl, bu, x, hesl, hesd, istate, out f, g, out ifail);
        Console.Out.Flush();
        //
             if (ifail == 0 || ifail == 3 || ifail == 5)
        {
          Console.WriteLine("");
          Console.WriteLine("  {0}{1,12:f4}", "Function value on exit is ", f);
          Console.Write(" " + " {0}", "at the point");
          for (j = 1; j <= n; j++)
          {
            Console.Write(" " + " {0, 12:f4}", x[j - 1]);
          }
          Console.WriteLine(" ");
          Console.WriteLine(" {0}", "The corresponding (machine dependent) gradient is");
          for (j = 1; j <= n; j++)
          {
            Console.Write(" " + " {0, 12:e3}", g[j - 1]);
          }
          Console.WriteLine(" ");
          Console.Write(" " + " {0}", "istate contains");
          for (j = 1; j <= n; j++)
          {
            Console.Write(" " + " {0, 5}", istate[j - 1]);
          }
          Console.WriteLine(" ");
          Console.Write(" " + " {0}", "and hesd contains");
          for (j = 1; j <= n; j++)
          {
            Console.Write(" " + " {0, 12:e4}", hesd[j - 1]);
          }
          Console.WriteLine(" ");
        }
      }
      //
      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.
      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);
      }
      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);
    }
    //
    public static void monit(int n, double[] xc, double fc, double[] gc, int[] istate,
    double gpjnrm,  double cond,  bool posdef,  int niter,  int nf) 
    { 
      //  Monitoring method 
      int isj,  j;
      Console.WriteLine("");
      Console.WriteLine(" {0}", " Itn     Fn evals              Fn value            Norm of proj gradient");
      Console.WriteLine("  {0,3}            {1,5}            {2,20:e4}            {3,20:e4}", niter, nf, fc, gpjnrm);
      Console.WriteLine("");
      Console.WriteLine(" {0}", " J           x[J-1]                g[J-1]           Status");
      for (j = 1; j <= n; j++)
      {
        isj = istate[j - 1];
        if (isj > 0)
        {
          Console.WriteLine("  {0,2}  {1,20:e4}{2,20:e4}{3}", j, xc[j - 1], gc[j - 1], "    Free");
        }
        else if (isj == -1)
        {
          Console.WriteLine("  {0,2}  {1,20:e4}{2,20:e4}{3}", j, xc[j - 1], gc[j - 1], "    Upper Bound");
        }
        else if (isj == -2)
        {
          Console.WriteLine("  {0,2}  {1,20:e4}{2,20:e4}{3}", j, xc[j - 1], gc[j - 1], "    Lower Bound");
        }
        else if (isj == -3)
        {
          Console.WriteLine("  {0,2}  {1,20:e4}{2,20:e4}{3}", j, xc[j - 1], gc[j - 1], "    ant");
        }
      }
      if (cond != 0.00e0)
      {
        if (cond > 1.00e6)
        {
          Console.WriteLine("");
          Console.WriteLine(" {0}", "Estimated condition number of projected Hessian is more than 1.0E+6");
        }
        else
        {
          Console.WriteLine("");
          Console.WriteLine("  {0}{1,10:e2}", "Estimated condition number of projected Hessian = ", cond);
        }
        if (!(posdef))
        {
          //            The following statement is included so that this monit
          //            can be used in conjunction with either of the method
          //            E04.e04kd or  E04.e04lb
          Console.WriteLine("");
          Console.WriteLine(" {0}", "Projected Hessian matrix is not positive definite");
        }
      }
      //
    }
  }
}