SparseMatrix: Create a pretty string of the matrix dimensions.

src/storm/storage/SparseMatrix.cpp

@@ -2150,6 +2150,17 @@ namespace storm {
             return true;
         }
 
+        template<typename ValueType>
+        std::string SparseMatrix<ValueType>::getDimensionsAsString() const {
+            std::string result = std::to_string(getRowCount()) + "x" + std::to_string(getColumnCount()) + " matrix (" + std::to_string(getNonzeroEntryCount()) + " non-zeroes";
+            if (!hasTrivialRowGrouping()) {
+                result += ", " + std::to_string(getRowGroupCount()) + " groups";
+            }
+            result += ")";
+            return result;
+        }
+
+        
         template<typename ValueType>
         std::ostream& operator<<(std::ostream& out, SparseMatrix<ValueType> const& matrix) {
             // Print column numbers in header.

src/storm/storage/SparseMatrix.h

@@ -963,6 +963,11 @@ namespace storm {
             template<typename TPrime>
             friend std::ostream& operator<<(std::ostream& out, SparseMatrix<TPrime> const& matrix);
 
+            /*!
+             * Returns a string describing the dimensions of the matrix.
+             */
+            std::string getDimensionsAsString() const;
+            
             /*!
              * Prints the matrix in a dense format, as also used by e.g. Matlab.
              * Notice that the format does not support multiple rows in a rowgroup.