Adding documentation and minor changes in MatrixMarketReader class

src/SparseTransform/Convert/IReader.cs

@@ -21,7 +21,7 @@ namespace SparseTransform.Convert
         /// <summary>
         /// auxiliary method for transforming <c>matrix</c> in a bipartit graph
         /// </summary>
-        /// <param name="matrix"></param>
+        /// <param name="matrix">input matrix string</param>
         /// <returns></returns>
         BipartiteGraph ReadBipartite(String matrix);
 

src/SparseTransform/Convert/MatrixMarketReader.cs

@@ -38,7 +38,11 @@ namespace SparseTransform.Convert
             }
         }
 
-
+        /// <summary>
+        /// checks with ANTLR4.0 whether the header is a valid instance. The header grammar can be found in the file MMFHeader.g4 
+        /// </summary>
+        /// <param name="header">header of the MMF-input</param>
+        /// <returns></returns>
         private bool checkHeader(string header)
         {
             AntlrInputStream stream = new AntlrInputStream(header);
@@ -52,6 +56,11 @@ namespace SparseTransform.Convert
         }
 
 
+       /// <summary>
+       /// checks whether the comment-section is valid.
+       /// </summary>
+       /// <param name="lines">entire input split by newlines</param>
+       /// <exception cref="Exception"></exception>
         private void checkComments(string[] lines)
         {
             bool leftComments = false;
@@ -79,6 +88,13 @@ namespace SparseTransform.Convert
         }
 
 
+        /// <summary>
+        /// creates a graph from the data-section of the MMF-input and meanwhile checks whether the data-section is valid
+        /// </summary>
+        /// <param name="matrix"></param>
+        /// <param name="graph"></param>
+        /// <returns></returns>
+        /// <exception cref="Exception"></exception>
         public IGraph ReadGraph(string[] matrix, IGraph graph)
         {
             string[] values;
@@ -101,7 +117,10 @@ namespace SparseTransform.Convert
                             int xCoordinate = Int32.Parse(values[0]);
                             int yCoordinate = Int32.Parse(values[1]);
                             String value = values[2];
-                            addEdge(xCoordinate, yCoordinate, graph);
+                            if (xCoordinate != yCoordinate)
+                            {
+                                graph.AddEdge(xCoordinate, yCoordinate);
+                            }
                         }
                     }
                 }
@@ -113,14 +132,13 @@ namespace SparseTransform.Convert
             }
         }
 
-        private void addEdge(int xCoordinate, int yCoordinate, IGraph g)
-        {
-            if (xCoordinate != yCoordinate)
-            {
-                g.AddEdge(xCoordinate, yCoordinate);
-            }
-        }
 
+
+        /// <summary>
+        /// computes the first data-line in the MMF-input 
+        /// </summary>
+        /// <param name="lines"></param>
+        /// <returns></returns>
         private int getFirstDataLine(String[] lines)
         {
             int firstDataLine = 0;

src/SparseTransform/Convert/MatrixMarketWriter.cs

@@ -25,6 +25,7 @@ namespace SparseTransform.Convert
         {
             if (seed)
             {
+                // ziemlich wilder ausdruck, wa? Liefert die seed matrix aus einem AdjacencyGraph oder BipartiteGraph. (je nachdem was IGraph ist)
                 IntegerMatrix matrix = graph.ToSeedMatrix(graph is AdjacencyGraph ? ((AdjacencyGraph)graph).GetNodeCount() : ((BipartiteGraph)graph).GetRightNodeCount());
                 if (matrix.RowCount != 0)
                 {
@@ -38,10 +39,13 @@ namespace SparseTransform.Convert
             }
         }
 
-
+        /// <summary>
+        /// todo
+        /// </summary>
+        /// <exception cref="NotImplementedException"></exception>
         private void CalculateCompressedMatrix()
         {
-            
+            throw new NotImplementedException();
         }
     }
 }
\ No newline at end of file

src/SparseTransform/Convert/VisitorHeader.cs

@@ -12,6 +12,13 @@ namespace Transform.Convert
 {
     internal class VisitorHeader : MMFHeaderBaseVisitor<bool>
     {
+
+
+        /// <summary>
+        /// visits the AST and helps to decide whether the input matrix is symmetric
+        /// </summary>
+        /// <param name="context"></param>
+        /// <returns></returns>
         public override bool VisitHeader([NotNull] MMFHeaderParser.HeaderContext context)
         {
             if ((context.format().choice1() is null || context.format().choice1().GENERAL() is null)