Removed stubs in SparseMatrix. Calculation of A^T*x is inefficient for CSR format so it defaults to generic calculation.

src/Numerics/LinearAlgebra/Double/SparseMatrix.cs

@@ -1443,27 +1443,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
                 }
             }
         }
-
-        /// <summary>
-        /// Multiplies the transpose of this matrix with a vector and places the results into the result vector.
-        /// </summary>
-        /// <param name="rightSide">The vector to multiply with.</param>
-        /// <param name="result">The result of the multiplication.</param>
-        protected override void DoTransposeThisAndMultiply(Vector<double> rightSide, Vector<double> result)
-        {
-            throw new NotImplementedException();
-        }
-
-        /// <summary>
-        /// Multiplies the transpose of this matrix with another matrix and places the results into the result matrix.
-        /// </summary>
-        /// <param name="other">The matrix to multiply with.</param>
-        /// <param name="result">The result of the multiplication.</param>
-        protected override void DoTransposeThisAndMultiply(Matrix<double> other, Matrix<double> result)
-        {
-            throw new NotImplementedException();
-        }
-
+        
         /// <summary>
         /// Negate each element of this matrix and place the results into the result matrix.
         /// </summary>