DoubleMatrixItem(Int32, Int32) Property

Gets or sets the element of this instance corresponding to the specified row and column indexes.

Definition

Namespace: Novacta.Analytics
Assembly: Novacta.Analytics (in Novacta.Analytics.dll) Version: 2.1.0+428f3840cfab98dda567bb0ed350b302533e273a
C#
public double this[
	int rowIndex,
	int columnIndex
] { get; set; }

Parameters

rowIndex  Int32
The zero-based row index of the element to get or set.
columnIndex  Int32
The zero-based column index of the element to get or set.

Property Value

Double
The element corresponding to the specified row and column indexes.

Implements

IReadOnlyTabularCollectionTValue, TCollectionItemInt32, Int32
ITabularCollectionTValue, TCollectionItemInt32, Int32

Example

In the following example, a matrix element is accessed using its row and column indexes.

C#
using System;

namespace Novacta.Analytics.CodeExamples
{
    public class MatrixIndexerExample00  
    {
        public void Main()
        {
            // Create a matrix.
            var data = new double[6] {
                10, 20, 30,
                40, 50, 60
            };
            var matrix = DoubleMatrix.Dense(2, 3, data, StorageOrder.RowMajor);
            Console.WriteLine("Initial data matrix:");
            Console.WriteLine(matrix);

            // Specify a row index.
            int rowIndex = 1;
            Console.WriteLine();
            Console.WriteLine("Row index: {0}", rowIndex);

            // Specify a column index.
            int columnIndex = 2;
            Console.WriteLine();
            Console.WriteLine("Column index: {0}", columnIndex);

            // Set the corresponding entry.
            matrix[rowIndex, columnIndex] = -60.0;

            Console.WriteLine();
            Console.WriteLine("Updated data matrix:");
            Console.WriteLine(matrix);

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

            Console.WriteLine();
            Console.WriteLine("Updated matrix entry:");
            Console.WriteLine(readOnlyMatrix[rowIndex, columnIndex]);
        }
    }
}

// Executing method Main() produces the following output:
// 
// Initial data matrix:
// 10               20               30               
// 40               50               60               
// 
// 
// 
// Row index: 1
// 
// Column index: 2
// 
// Updated data matrix:
// 10               20               30               
// 40               50               -60              
// 
// 
// 
// Updated matrix entry:
// -60

Exceptions

ArgumentOutOfRangeExceptionrowIndex is less than zero.
-or-
rowIndex is equal to or greater than NumberOfRows.
-or-
columnIndex is less than zero.
-or-
columnIndex is equal to or greater than NumberOfColumns.

See Also