DoubleMatrixVec Method

Returns the vectorization of this instance.

Definition

Namespace: Novacta.Analytics
Assembly: Novacta.Analytics (in Novacta.Analytics.dll) Version: 2.1.0+428f3840cfab98dda567bb0ed350b302533e273a
C#
public DoubleMatrix Vec()

Return Value

DoubleMatrix
A column vector obtained by stacking the columns of this instance.

Remarks

Let LaTeX equation be a matrix, and consider its generic entry

LaTeX equation

where LaTeX equation and LaTeX equation are the number of rows and columns of LaTeX equation, respectively.

A linear index completely identifies an entry, assuming that entries are linearly ordered following the ColumnMajor data order. This means that entry LaTeX equation has linear index equal to LaTeX equation, and matrix entries can be enumerated as follows:

LaTeX equation

where LaTeX equation is the Count of the matrix.

This method, when called on a DoubleMatrix instance representing matrix LaTeX equation, returns a new DoubleMatrix instance that represents a column vector, say LaTeX equation, such that:

LaTeX equation

Example

In the following example, a matrix is vectorized.

C#
using System;

namespace Novacta.Analytics.CodeExamples
{
    public class VecExample0  
    {
        public void Main()
        {
            // Create a matrix.
            var data = new double[9] {
                1, 2, 3,
                4, 5, 6,
                7, 8, 9
            };
            var matrix = DoubleMatrix.Dense(3, 3, data, StorageOrder.RowMajor);
            Console.WriteLine("Initial data matrix:");
            Console.WriteLine(matrix);

            // Get the vectorization of the data matrix.
            var vectorized = matrix.Vec();

            Console.WriteLine();
            Console.WriteLine("Vectorized data matrix:");
            Console.WriteLine(vectorized);

            // Entries can also be vectorized using a read-only wrapper of the matrix.
            ReadOnlyDoubleMatrix readOnlyMatrix = matrix.AsReadOnly();

            Console.WriteLine();
            Console.WriteLine("Vectorized read-only data matrix :");
            Console.WriteLine(readOnlyMatrix.Vec());
        }
    }
}

// Executing method Main() produces the following output:
// 
// Initial data matrix:
// 1                2                3                
// 4                5                6                
// 7                8                9                
// 
// 
// 
// Vectorized data matrix:
// 1                
// 4                
// 7                
// 2                
// 5                
// 8                
// 3                
// 6                
// 9                
// 
// 
// 
// Vectorized read-only data matrix :
// 1                
// 4                
// 7                
// 2                
// 5                
// 8                
// 3                
// 6                
// 9                
// 
//

See Also