Optimized loop in IsSymmetric. Instead of checking row >= column, have the column loop run from row + 1.

src/Numerics/LinearAlgebra/Generic/Matrix.cs

@@ -1782,13 +1782,8 @@ namespace MathNet.Numerics.LinearAlgebra.Generic
 
                 for (var row = 0; row < RowCount; row++)
                 {
-                    for (var column = 0; column < ColumnCount; column++)
+                    for (var column = row + 1; column < ColumnCount; column++)
                     {
-                        if (column >= row)
-                        {
-                            continue;
-                        }
-
                         if (!At(row, column).Equals(At(column, row)))
                         {
                             return false;