Fixing some code analysis warnings.

Sources/Accord.IO/ExcelReader.cs

@@ -357,28 +357,9 @@ public DataSet GetWorksheet()
             return dataset;
         }
 
-
-        private bool unquote(string str, char quote, out string unquoted)
-        {
-            unquoted = str;
-
-            if (String.IsNullOrEmpty(str))
-                return false;
-
-            int length = str.Length;
-            if (length > 1 && str[0] == quote && str[length - 1] == quote)
-            {
-                unquoted = str.Substring(1, length - 2);
-                return true;
-            }
-
-            return false;
-        }
-
     }
 
 
-
 #if NET35
     internal static class Extensions
     {

Sources/Accord.Math/Distances/Mahalanobis.cs

@@ -126,7 +126,7 @@ public double Distance(double[] x, double[] y)
         ///   of the given covariance matrix.
         /// </returns>
         /// 
-        public SquareMahalanobis FromCovarianceMatrix(double[,] covariance)
+        public static SquareMahalanobis FromCovarianceMatrix(double[,] covariance)
         {
             return new SquareMahalanobis(new CholeskyDecomposition(covariance));
         }
@@ -141,7 +141,7 @@ public SquareMahalanobis FromCovarianceMatrix(double[,] covariance)
         ///   A Mahalanobis distance using the given precision matrix.
         /// </returns>
         /// 
-        public SquareMahalanobis FromPrecisionMatrix(double[,] precision)
+        public static SquareMahalanobis FromPrecisionMatrix(double[,] precision)
         {
             return new SquareMahalanobis(precision);
         }

Sources/Accord.Statistics/Accord.MachineLearning/Learning/ParallelMulticlassLearningBase.cs

@@ -58,7 +58,7 @@ public override CancellationToken Token
         /// <summary>
         /// Initializes a new instance of the <see cref="ParallelMulticlassLearningBase{TModel, TInput}"/> class.
         /// </summary>
-        public ParallelMulticlassLearningBase()
+        protected ParallelMulticlassLearningBase()
         {
             ParallelOptions = new ParallelOptions();
         }

Sources/Accord.Statistics/Distances/Bhattacharyya.cs

@@ -247,14 +247,14 @@ public double Distance(double[] meanX, double[,] covX, double[] meanY, double[,]
         ///   Bhattacharyya distance between two Gaussian distributions.
         /// </summary>
         /// 
-        /// <param name="a">The first Normal distribution.</param>
-        /// <param name="b">The second Normal distribution.</param>
+        /// <param name="x">The first Normal distribution.</param>
+        /// <param name="y">The second Normal distribution.</param>
         /// 
         /// <returns>The Bhattacharyya distance between the two distributions.</returns>
         /// 
-        public double Distance(MultivariateNormalDistribution a, MultivariateNormalDistribution b)
+        public double Distance(MultivariateNormalDistribution x, MultivariateNormalDistribution y)
         {
-            return Distance(a.Mean, a.Covariance, b.Mean, b.Covariance);
+            return Distance(x.Mean, x.Covariance, y.Mean, y.Covariance);
         }
     }
 }