DoubleMatrixMultiply(Double, DoubleMatrix) Operator

Determines the multiplication of a scalar by a matrix.

Definition

Namespace: Novacta.Analytics
Assembly: Novacta.Analytics (in Novacta.Analytics.dll) Version: 2.1.0+428f3840cfab98dda567bb0ed350b302533e273a

public static DoubleMatrix operator *(
	double left,
	DoubleMatrix right
)

Public Shared Operator * ( 
	left As Double,
	right As DoubleMatrix
) As DoubleMatrix

C++

public:
static DoubleMatrix^ operator *(
	double left, 
	DoubleMatrix^ right
)

static let inline (*)
        left : float * 
        right : DoubleMatrix  : DoubleMatrix

Parameters

left Double: The left operand.
right DoubleMatrix: The right operand.

Return Value

DoubleMatrix
The result of multiplying right by left.

Remarks

Let LaTeX equation and be the right number of rows and columns, respectively, and let its generic entry given by

The method returns a matrix having the same dimensions of right, whose generic entry is:

LaTeX equation

Example

In the following example, a scalar is multiplied by a matrix.

using System;

namespace Novacta.Analytics.CodeExamples
{
    public class MultiplicationExample2  
    {
        public void Main()
        {
            // Create the left operand.
            double left = 10.0;
            Console.WriteLine("left =");
            Console.WriteLine(left);
            Console.WriteLine();

            // Create the right operand.
            var data = new double[6] {
                0,  20,  40,
               10,  30,  50,
            };
            var right = DoubleMatrix.Dense(2, 3, data, StorageOrder.RowMajor);
            Console.WriteLine("right =");
            Console.WriteLine(right);

            // Multiply left by right.
            var result = left * right;

            Console.WriteLine();
            Console.WriteLine("left * right =");
            Console.WriteLine(result);

            // In .NET languages that do not support overloaded operators,
            // you can use the alternative methods named Multiply.
            result = DoubleMatrix.Multiply(left, right);

            Console.WriteLine();
            Console.WriteLine("DoubleMatrix.Multiply(left, right) returns");
            Console.WriteLine();
            Console.WriteLine(result);

            // Both operators and alternative methods are overloaded to 
            // support read-only matrix arguments.
            // Compute the product using a read-only wrapper of right.
            ReadOnlyDoubleMatrix readOnlyRight = right.AsReadOnly();
            result = left * readOnlyRight;

            Console.WriteLine();
            Console.WriteLine("left * readOnlyRight =");
            Console.WriteLine(result);
        }
    }
}

// Executing method Main() produces the following output:
// 
// left =
// 10
// 
// right =
// 0                20               40               
// 10               30               50               
// 
// 
// 
// left * right =
// 0                200              400              
// 100              300              500              
// 
// 
// 
// DoubleMatrix.Multiply(left, right) returns
// 
// 0                200              400              
// 100              300              500              
// 
// 
// 
// left * readOnlyRight =
// 0                200              400              
// 100              300              500              
// 
//

Exceptions

ArgumentNullException

right is null.