Xml comments.

MathLight/LinearAlgebra/LUDecomposition.cs

@@ -11,8 +11,14 @@ namespace Ecng.MathLight.LinearAlgebra
     /// </summary>
     public class LUDecomposition
     {
-        public double[,] L { private set; get; }
-        public double[,] U { private set; get; }
+		/// <summary>
+		/// The lower triangular matrix.
+		/// </summary>
+		public double[,] L { private set; get; }
+		/// <summary>
+		/// The upper triangular matrix.
+		/// </summary>
+		public double[,] U { private set; get; }
 
         private readonly int[] _permutation;
         private readonly double[] _rowBuffer;
@@ -80,7 +86,12 @@ public LUDecomposition(double[,] matrix)
             }
         }
 
-        public double[,] Solve(double[,] matrix)
+		/// <summary>
+		/// Solve the system of linear equations.
+		/// </summary>
+		/// <param name="matrix">The matrix.</param>
+		/// <returns>The value.</returns>
+		public double[,] Solve(double[,] matrix)
         {
             if (matrix.Rows() != L.Rows())
             {
@@ -109,6 +120,11 @@ public LUDecomposition(double[,] matrix)
             return ret;
         }
 
+		/// <summary>
+		/// Solve the system of linear equations.
+		/// </summary>
+		/// <param name="vector">The vector.</param>
+		/// <returns>The value.</returns>
 		[CLSCompliant(false)]
         public double[] Solve(double[] vector)
         {

MathLight/LinearAlgebra/PolyFit.cs

@@ -5,7 +5,10 @@
 
 namespace Ecng.MathLight.LinearAlgebra
 {
-    public class PolyFit
+	/// <summary>
+	/// Implements simple Matrix functions needed for polynomial fitting
+	/// </summary>
+	public class PolyFit
     {
         /// <summary>
         /// Coefficients of a polynomial starting at the constant coefficient 

MathLight/Normal.cs

@@ -2,6 +2,9 @@
 
 using System;
 
+/// <summary>
+/// The normal distribution.
+/// </summary>
 public static class Normal
 {
 	// MathNet.Numerics
@@ -35,11 +38,17 @@ public static class Normal
 	private static readonly double[] ErfImpNn = [-7.892247039787227E-06, 6.22088451660987E-07, 1.457284456768824E-08, 6.0371550554271534E-11];
 	private static readonly double[] ErfImpNd = [1.0, 0.037532884635629371, 0.00046791953597462532, 1.9384703927584565E-06];
 
+	/// <summary>
+	/// Evaluate the polynomial.
+	/// </summary>
+	/// <param name="z">The z.</param>
+	/// <param name="coefficients">The coefficients.</param>
+	/// <returns>The result.</returns>
 	public static double Evaluate(double z, params double[] coefficients)
 	{
 		if (coefficients == null)
 		{
-			throw new ArgumentNullException("coefficients");
+			throw new ArgumentNullException(nameof(coefficients));
 		}
 
 		int num = coefficients.Length;
@@ -58,6 +67,11 @@ public static double Evaluate(double z, params double[] coefficients)
 		return num2;
 	}
 
+	/// <summary>
+	/// The cumulative distribution.
+	/// </summary>
+	/// <param name="x">The x.</param>
+	/// <returns>The cumulative distribution.</returns>
 	public static double CumulativeDistribution(double x)
 	{
 		static double ErfImp(double z, bool invert)