DoubleMatrixSubtraction(DoubleMatrix, DoubleMatrix) Operator

Determines the difference between two matrices.

Definition

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

C#

public static DoubleMatrix operator -(
	DoubleMatrix left,
	DoubleMatrix right
)

VB

Public Shared Operator - ( 
	left As DoubleMatrix,
	right As DoubleMatrix
) As DoubleMatrix

C++

public:
static DoubleMatrix^ operator -(
	DoubleMatrix^ left, 
	DoubleMatrix^ right
)

F#

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

Parameters

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

Return Value

DoubleMatrix
The result of subtracting right from left.

Remarks

Let LaTeX equation and be the left number of rows and columns, respectively, and consider its generic entry

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

LaTeX equation

The method operates as follows.

If left is scalar, then the method returns a matrix having the same dimensions of right, whose generic entry is:
If right is scalar, then the method returns a matrix having the same dimensions of left, whose generic entry is:
If neither left nor right is scalar, then the method returns a matrix whose generic entry is

provided that the dimensions of left agree with those of right; otherwise, an exception is thrown.

Example

In the following example, the difference between two matrices is computed.

C#

using System;

namespace Novacta.Analytics.CodeExamples
{
    public class SubtractionExample0  
    {
        public void Main()
        {
            // Create the left operand.
            var data = new double[6] {
                0,  2,  4,
                1,  3,  5,
            };
            var left = DoubleMatrix.Dense(2, 3, data, StorageOrder.RowMajor);
            Console.WriteLine("left =");
            Console.WriteLine(left);

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

            // Subtract right from left.
            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 Subtract.
            result = DoubleMatrix.Subtract(left, right);

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

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

            Console.WriteLine();
            Console.WriteLine("readOnlyLeft - right =");
            Console.WriteLine(result);
        }
    }
}

// Executing method Main() produces the following output:
// 
// left =
// 0                2                4                
// 1                3                5                
// 
// 
// right =
// 0                20               40               
// 10               30               50               
// 
// 
// 
// left - right =
// 0                -18              -36              
// -9               -27              -45              
// 
// 
// 
// DoubleMatrix.Subtract(left, right) returns
// 
// 0                -18              -36              
// -9               -27              -45              
// 
// 
// 
// readOnlyLeft - right =
// 0                -18              -36              
// -9               -27              -45              
// 
//

Exceptions

ArgumentNullException	left is null. -or- right is null.
ArgumentException	Both left and right are not scalar matrices, and they have not the same number of rows and columns.