Sorting

Files
file	lists/sorting.hpp

Functions
std::unique_ptr< column >	cudf::lists::sort_lists (lists_column_view const &source_column, order column_order, null_order null_precedence, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Segmented sort of the elements within a list in each row of a list column. More...
std::unique_ptr< column >	cudf::lists::stable_sort_lists (lists_column_view const &source_column, order column_order, null_order null_precedence, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
	Segmented sort of the elements within a list in each row of a list column using stable sort. More...

Detailed Description

Function Documentation

sort_lists()

std::unique_ptr<column> cudf::lists::sort_lists	(	lists_column_view const &	source_column,
		order	column_order,
		null_order	null_precedence,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Segmented sort of the elements within a list in each row of a list column.

source_column with depth 1 is only supported.

• source_column            : [{4, 2, 3, 1}, {1, 2, NULL, 4}, {-10, 10, 0}]
   
  Ascending,  Null After   : [{1, 2, 3, 4}, {1, 2, 4, NULL}, {-10, 0, 10}]
  Ascending,  Null Before  : [{1, 2, 3, 4}, {NULL, 1, 2, 4}, {-10, 0, 10}]
  Descending, Null After   : [{4, 3, 2, 1}, {NULL, 4, 2, 1}, {10, 0, -10}]
  Descending, Null Before  : [{4, 3, 2, 1}, {4, 2, 1, NULL}, {10, 0, -10}]

Parameters

source_column	View of the list column of numeric types to sort
column_order	The desired sort order
null_precedence	The desired order of null compared to other elements in the list
mr	Device memory resource to allocate any returned objects

Returns

list column with elements in each list sorted.

stable_sort_lists()

std::unique_ptr<column> cudf::lists::stable_sort_lists	(	lists_column_view const &	source_column,
		order	column_order,
		null_order	null_precedence,
		rmm::mr::device_memory_resource *	mr = rmm::mr::get_current_device_resource()
	)

Segmented sort of the elements within a list in each row of a list column using stable sort.

Segmented sort of the elements within a list in each row of a list column. source_column with depth 1 is only supported.

• source_column            : [{4, 2, 3, 1}, {1, 2, NULL, 4}, {-10, 10, 0}]
   
  Ascending,  Null After   : [{1, 2, 3, 4}, {1, 2, 4, NULL}, {-10, 0, 10}]
  Ascending,  Null Before  : [{1, 2, 3, 4}, {NULL, 1, 2, 4}, {-10, 0, 10}]
  Descending, Null After   : [{4, 3, 2, 1}, {NULL, 4, 2, 1}, {10, 0, -10}]
  Descending, Null Before  : [{4, 3, 2, 1}, {4, 2, 1, NULL}, {10, 0, -10}]

Parameters

source_column	View of the list column of numeric types to sort
column_order	The desired sort order
null_precedence	The desired order of null compared to other elements in the list
mr	Device memory resource to allocate any returned objects

Returns

list column with elements in each list sorted.