Sorting¶

In oneDAL sorting is an algorithm to sort the observations by each feature (column) in the ascending order.

The result of the sorting algorithm applied to the matrix \(X = (x_{ij})_{n \times p}\) is the matrix \(Y = (y_{ij})_{n \times p}\) where the \(j\)-th column \((Y)_j = ( y_{ij} )\), \(i = 1, \ldots, n\), is the column \((X)_j = ( x_{ij} )\), \(i = 1, \ldots, n\), sorted in the ascending order.

Batch Processing¶

Algorithm Input¶

The sorting algorithm accepts the input described below. Pass the Input ID as a parameter to the methods that provide input for your algorithm. For more details, see Algorithms.

Algorithm Input for Sorting (Batch Processing)¶
Input ID	Input
`data`	Pointer to the \(n \times p\) numeric table that contains the input data set. This table can be an object of any class derived from `NumericTable` except `PackedSymmetricMatrix`, `PackedTriangularMatrix`, and `CSRNumericTable`.

Algorithm Parameters¶

The sorting algorithm has the following parameters:

Algorithm Parameters for Sorting (Batch Processing)¶
Parameter	Default Value	Description
`algorithmFPType`	`float`	The floating-point type that the algorithm uses for intermediate computations. Can be `float` or `double`.
`method`	`defaultDense`	The radix method for sorting a data set, the only method supported by the algorithm.

Algorithm Output¶

The sorting algorithm function calculates the result described below. Pass the Result ID as a parameter to the methods that access the results of your algorithm. For more details, see Algorithms.

Algorithm Output for Sorting (Batch Processing)¶
Result ID	Result
`sortedData`	Pointer to the \(n \times p\) numeric table that stores the results of sorting.

Note

If the number of feature vectors is greater than or equal to \(2^{31}\), the library uses the quick sort method instead of radix sort.

Examples¶

Batch Processing:

sorting_dense_batch.cpp

oneDAL documentation