//      g02aa Example Program Text
//      C# version, NAG Copyright 2008
using System;
using NagLibrary;
using System.Globalization;
using System.IO;
namespace NagDotNetExamples
{
  public class G02AAE
  {
    static void Main(String[] args)
    {
      StartExample();
    }
    public static void StartExample()
    {
      try
      {
        double errtol,   nrmgrd; int feval,  i,  iter,  j,  maxit,  maxits,  n;
        int ifail;
        Console.WriteLine("g02aa Example Program Results");
        Console.WriteLine("");
        // 
        //      Set up matrix G
        n = 4;
        double[,] g = new double[n, n];
        double[,] x = new double[n, n];
        for (j = 1; j <= n; j++)
        {
          for (i = 1; i <= n; i++)
          {
            g[i - 1, j - 1] = 0.0;
          }
          g[j - 1, j - 1] = 2.00e0;
        }
        for (j = 2; j <= n; j++)
        {
          g[j - 1 - 1, j - 1] = -1.00e0;
          g[j - 1, j - 1 - 1] = -1.00e0;
        }
        // 
        //      Set up method parameters
        errtol = 1.00e-7;
        maxits = 200;
        maxit = 10;
        // 
        G02.g02aa(g, n, errtol, maxits, maxit, x, out iter, out feval, out nrmgrd, out ifail);
        // 
        if (ifail == 0)
        {
          Console.WriteLine(" {0}", "     Nearest Correlation Matrix\r\n");
          for (i = 1; i <= n; i++)
          {
            for (j = 1; j <= n; j++)
            {
              Console.Write(" {0,11:f5}{1}", x[i - 1, j - 1],j%4==0? "\n":"");
            }
          }
          Console.WriteLine("");
          Console.WriteLine("");
          Console.WriteLine("{0}{1,11}", " Number of Newton steps taken:", iter);
          Console.WriteLine("{0}{1,9}", " Number of function evaluations:", feval);
          if (nrmgrd > errtol)
          {
            Console.WriteLine("{0}{1,11:e3}", " Norm of gradient of last Newton step:", nrmgrd);
          }
        }
        else
        {
          Console.WriteLine("** g02aa failed with ifail = {0,5}", ifail);
        }
        Console.WriteLine("");
        // 
      }
      catch (Exception e)
      {
        Console.WriteLine(e.Message);
        Console.WriteLine("Exception Raised");
      }
    }
  }
}