//      g02ab Example Program Text
//      C# version, NAG Copyright 2012
using System;
using NagLibrary;
using System.Globalization;
namespace NagDotNetExamples
{

    public class G02ABE
    {

        static string datafile = "ExampleData/g02abe.d";
        // Specify data file 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()
        {
            try
            {
               DataReader sr = new DataReader(datafile);
                //      g02ab Example Program Text
                //      Mark 24 Release. NAG Copyright 2012.
               
                double alpha,
                errtol,
                nrmgrd;
                int feval = 0,
                i = 0,
                ifail = 0,
                iter = 0,
                ldg = 0,
                ldx = 0,
                lwork = 0,
                maxit = 0,
                maxits = 0,
                n = 0;
                string opt = "";

                Console.WriteLine(" {0}", "g02ab Example Program Results");
                Console.WriteLine("");
                //      Skip heading in data file
                sr.Reset();
                //      Read in the problem size, opt and alpha
                sr.Reset();
                n = int.Parse(sr.Next());
                opt = sr.Next();
                alpha = double.Parse(sr.Next(), CultureInfo.InvariantCulture);
                ldg = (int)n;
                ldx = (int)n;
                lwork = 66 * n;
                // allocate
                //      Read in the matrix G

                double[] eig = new double[n];
                double[,] g = new double[ldg, n];
                double[] w = new double[n];
                double[] work = new double[lwork];
                double[,] x = new double[ldx, n];
                sr.Reset();
                for (i = 1; i <= n; i++)
                {
                    for (int j = 0; j < n; j++)
                    {
                        g[i - 1, j] = double.Parse(sr.Next(), CultureInfo.InvariantCulture);
                    }

                }
                //      Read in the vector W
                sr.Reset();
                for (int j = 0; j < n; j++)
                {
                    w[j] = double.Parse(sr.Next(), CultureInfo.InvariantCulture);
                }
                //      Use the defaults for ERRTOL, MAXITS and MAXIT
                errtol = 0.00e0;
                maxits = 0;
                maxit = 0;
                //      Calculate nearest correlation matrix
                ifail = 0;
                G02.g02ab(g, n, opt, alpha, w, errtol, maxits, maxit, x, out iter, out feval, out nrmgrd, out ifail);
                //      Display results
                ifail = 0;
                X04.x04ca("General", "", n, n, x, "Nearest Correlation Matrix X", out ifail);
                Console.WriteLine("");
                Console.WriteLine("  {0}{1,11}", "Number of Newton steps taken:", iter);
                Console.WriteLine("  {0}{1,9}", "Number of function evaluations:", feval);
                Console.WriteLine("");
                Console.WriteLine("  {0}{1,37:f3}", "ALPHA: ", alpha);
                ifail = 0;
                //      The NAG name equivalent of dsyev is F08.f08fa;
                String jobz = "N";
                String uplo = "U";
                F08.f08fa(jobz, uplo, n, x, eig, out ifail);

                Console.WriteLine("");
                double[,] eig_prime = new double[1, n];
                for (i = 0; i < n; i++)
                {
                    eig_prime[0, i] = eig[i];
                }
                X04.x04ca("General", "", 1, n, eig_prime, "Eigenvalues of X", out ifail);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Console.WriteLine("Exception Raised");
            }
        }
    }
}