Dense matrix scalar multiplication optimization.

src/Numerics/LinearAlgebra/Double/DenseMatrix.cs

@@ -283,6 +283,15 @@ namespace MathNet.Numerics.LinearAlgebra.Double
             Control.LinearAlgebraProvider.SubtractArrays(Data, other.Data, Data);
         }
 
+        /// <summary>
+        /// Multiplies each element of this matrix with a scalar.
+        /// </summary>
+        /// <param name="scalar">The scalar to multiply with.</param>
+        public override void Multiply(double scalar)
+        {
+            Control.LinearAlgebraProvider.ScaleArray(scalar, Data);
+        }
+
         /// <summary>
         /// Multiplies this dense matrix with another dense matrix and places the results into the result dense matrix.
         /// </summary>

src/Numerics/LinearAlgebra/Double/Matrix.Arithmetic.cs

@@ -97,6 +97,7 @@ namespace MathNet.Numerics.LinearAlgebra.Double
                     }
                 });
         }
+
         /// <summary>
         /// Multiplies each element of this matrix with a scalar.
         /// </summary>