//      c05rd Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
namespace NagDotNetExamples
{
  public class C05RDE
  {
    static void Main(String[] args)
    {
      StartExample();
    }
    public static void StartExample()
    {
      try
      {
        const int n=9;
        const double zero=0.00e0;
        const double one=1.00e0;
        const double two=2.00e0;
        const double three=3.00e0;
        const double four=4.00e0;
        double factor,  fnorm,  xtol=0.0; int icount=0, irevcm=0, j=0, k=0, mode;
        double[] diag = new double[n];
        double[,] fjac = new double[n, n];
        double[] fvec = new double[n];
        double[] qtf = new double[n];
        double[] r = new double[n*(n + 1)/2];
        double[] x = new double[n];
        int ifail;
        Console.WriteLine("c05rd Example Program Results");
        //      The following starting values provide a rough solution.
        for (j = 1 ; j <= n ; j++)
        {
          x[j - 1] =  -1.00e0;
        }
        xtol = Math.Sqrt(X02.x02aj());
        for (j = 1 ; j <= n ; j++)
        {
          diag[j - 1] = 1.00e0;
        }
        mode = 2;
        factor = 100.00e0;
        //
	// C05.c05pdCommunications communications  = new C05.c05pdCommunications(n);
        C05.c05rdCommunications communications  = new C05.c05rdCommunications(n);
        do
        {
		/*C05.c05pd(ref irevcm, n, x, fvec, fjac, xtol, diag, mode, factor, r, qtf, 
          communications, out ifail );*/
          C05.c05rd(ref irevcm, n, x, fvec, fjac, xtol, mode, diag, factor, r, qtf, 
          communications, out ifail );
          //
          if (irevcm == 1)
          {
            icount = icount + 1;
            //         Insert print statements here to monitor progess if desired
          }
          else if (irevcm == 2)
          {
            //         Evaluate functions at current point
            for (k = 1 ; k <= n ; k++)
            {
              fvec[k - 1] = (three - two * x[k - 1]) * x[k - 1] + one;
              if (k > 1)
              {
                fvec[k - 1] = fvec[k - 1] - x[k - 2];
              }
              if (k < n)
              {
                fvec[k - 1] = fvec[k - 1] - two * x[k];
              }
            }
          }
          else if (irevcm == 3)
          {
            //         Evaluate Jacobian at current point
            for (k = 1 ; k <= n ; k++)
            {
              for (j = 1 ; j <= n ; j++)
              {
                fjac[k - 1 , j - 1] = zero;
              }
              fjac[k - 1 , k - 1] = three - four * x[k - 1];
              if (k != 1)
              {
                fjac[k - 1 , k - 2] =  -one;
              }
              if (k != n)
              {
                fjac[k - 1 , k] =  -two;
              }
            }
          }
          } while (irevcm != 0);
          //
          Console.WriteLine("");
          if (ifail == 0)
          {
            fnorm = F06.f06ej(n, fvec, 1, out ifail);
            Console.WriteLine("  {0}{1,4}{2}{3,12:e4}","Final 2 norm of the residuals after",icount," iterations is ",fnorm);
            Console.WriteLine("");
            Console.WriteLine(" {0}","Final approximate solution");
            for (j = 1 ; j <= n ; j++)
            {
              Console.Write(" {0, 10:f4}{1}", x[j - 1], j%3==0?"\n":"");
            }
            Console.WriteLine("");
          }
          else if (ifail == 1)
          {
            Console.WriteLine("");
            Console.WriteLine("** c05rd failed with ifail = {0,5}", ifail);
          }
          else
          {
            Console.WriteLine("  {0}{1,4}","ifail =",ifail);
            if (ifail >= 2)
            {
              Console.WriteLine(" {0}","Approximate solution");
              for (j = 1 ; j <= n ; j++)
              {
                Console.Write(" {0, 10:f4}{1}", x[j - 1], j%3==0?"\n":"");
              }
              Console.WriteLine("");
            }
          }
          //
        }
        catch (Exception e)
        {
          Console.WriteLine(e.Message);
          Console.WriteLine("Exception Raised");
        }
        Console.WriteLine("");
      }
    }
  }