mathnet-numerics/examples/examples-csharp/LinearAlgebra/MatrixSpecialNumbers.cs

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using System;
using System.Globalization;
using MathNet.Numerics.LinearAlgebra.Double;

namespace Examples.LinearAlgebraExamples
{
    /// <summary>
    /// Special numbers associated with any square matrix
    /// </summary>
    /// <seealso cref="http://reference.wolfram.com/mathematica/ref/Det.html">The determinant of the square matrix</seealso>
    /// <seealso cref="http://reference.wolfram.com/mathematica/ref/Tr.html">The trace of the matrix</seealso>
    /// <seealso cref="http://reference.wolfram.com/mathematica/ref/MatrixRank.html">The rank of the matrix</seealso>
    public class MatrixSpecialNumbers : IExample
    {
        /// <summary>
        /// Gets the name of this example
        /// </summary>
        public string Name
        {
            get
            {
                return "Special numbers associated with any square matrix";
            }
        }

        /// <summary>
        /// Gets the description of this example
        /// </summary>
        public string Description
        {
            get
            {
                return "Matrix properties as: Determinant, Condition Number, Rank and Trace";
            }
        }

        /// <summary>
        /// Run example
        /// </summary>
        /// <seealso cref="http://en.wikipedia.org/wiki/Determinant">Determinant</seealso>
        /// <seealso cref="http://en.wikipedia.org/wiki/Rank_%28linear_algebra%29">Rank (linear algebra)</seealso>
        /// <seealso cref="http://en.wikipedia.org/wiki/Trace_%28linear_algebra%29">Trace (linear algebra)</seealso>
        /// <seealso cref="http://en.wikipedia.org/wiki/Condition_number">Condition number</seealso>
        public void Run()
        {
            // Format matrix output to console
            var formatProvider = (CultureInfo)CultureInfo.InvariantCulture.Clone();
            formatProvider.TextInfo.ListSeparator = " ";

            // Create random square matrix
            var matrix = new DenseMatrix(5);
            var rnd = new Random(1); 
            for (var i = 0; i < matrix.RowCount; i++)
            {
                for (var j = 0; j < matrix.ColumnCount; j++)
                {
                    matrix[i, j] = rnd.NextDouble();
                }
            }

            Console.WriteLine(@"Initial matrix");
            Console.WriteLine(matrix.ToString("#0.00\t", formatProvider));
            Console.WriteLine();

            // 1. Determinant
            Console.WriteLine(@"1. Determinant");
            Console.WriteLine(matrix.Determinant());
            Console.WriteLine();

            // 2. Rank
            Console.WriteLine(@"2. Rank");
            Console.WriteLine(matrix.Rank());
            Console.WriteLine();

            // 3. Condition number
            Console.WriteLine(@"2. Condition number");
            Console.WriteLine(matrix.ConditionNumber());
            Console.WriteLine();

            // 4. Trace
            Console.WriteLine(@"4. Trace");
            Console.WriteLine(matrix.Trace());
            Console.WriteLine();
        }
    }
}