cudf::aggregation Class Reference

Abstract base class for specifying the desired aggregation in an aggregation_request. More...

#include <aggregation.hpp>

Inheritance diagram for cudf::aggregation:

Public Types
enum	Kind {   SUM , PRODUCT , MIN , MAX ,   COUNT_VALID , COUNT_ALL , ANY , ALL ,   SUM_OF_SQUARES , MEAN , M2 , VARIANCE ,   STD , MEDIAN , QUANTILE , ARGMAX ,   ARGMIN , NUNIQUE , NTH_ELEMENT , ROW_NUMBER ,   RANK , COLLECT_LIST , COLLECT_SET , LEAD ,   LAG , PTX , CUDA , MERGE_LISTS ,   MERGE_SETS , MERGE_M2 , COVARIANCE , CORRELATION ,   TDIGEST , MERGE_TDIGEST , HISTOGRAM , MERGE_HISTOGRAM }
	Possible aggregation operations. More...

Public Member Functions
	aggregation (aggregation::Kind a)
	Construct a new aggregation object. More...
virtual bool	is_equal (aggregation const &other) const
	Compares two aggregation objects for equality. More...
virtual size_t	do_hash () const
	Computes the hash value of the aggregation. More...
virtual std::unique_ptr< aggregation >	clone () const =0
	Clones the aggregation object. More...
virtual std::vector< std::unique_ptr< aggregation > >	get_simple_aggregations (data_type col_type, cudf::detail::simple_aggregations_collector &collector) const =0
	Get the simple aggregations that this aggregation requires to compute. More...
virtual void	finalize (cudf::detail::aggregation_finalizer &finalizer) const =0
	Compute the aggregation after pre-requisite simple aggregations have been computed. More...

Public Attributes
Kind	kind
	The aggregation to perform.

Detailed Description

Abstract base class for specifying the desired aggregation in an aggregation_request.

All aggregations must derive from this class to implement the pure virtual functions and potentially encapsulate additional information needed to compute the aggregation.

Definition at line 80 of file aggregation.hpp.

Member Enumeration Documentation

Kind

enum cudf::aggregation::Kind

Possible aggregation operations.

Enumerator
SUM	sum reduction
PRODUCT	product reduction
MIN	min reduction
MAX	max reduction
COUNT_VALID	count number of valid elements
COUNT_ALL	count number of elements
ANY	any reduction
ALL	all reduction
SUM_OF_SQUARES	sum of squares reduction
MEAN	arithmetic mean reduction
M2	sum of squares of differences from the mean
VARIANCE	variance
STD	standard deviation
MEDIAN	median reduction
QUANTILE	compute specified quantile(s)
ARGMAX	Index of max element.
ARGMIN	Index of min element.
NUNIQUE	count number of unique elements
NTH_ELEMENT	get the nth element
ROW_NUMBER	get row-number of current index (relative to rolling window)
RANK	get rank of current index
COLLECT_LIST	collect values into a list
COLLECT_SET	collect values into a list without duplicate entries
LEAD	window function, accesses row at specified offset following current row
LAG	window function, accesses row at specified offset preceding current row
PTX	PTX UDF based reduction.
CUDA	CUDA UDF based reduction.
MERGE_LISTS	merge multiple lists values into one list
MERGE_SETS	merge multiple lists values into one list then drop duplicate entries
MERGE_M2	merge partial values of M2 aggregation,
COVARIANCE	covariance between two sets of elements
CORRELATION	correlation between two sets of elements
TDIGEST	create a tdigest from a set of input values
MERGE_TDIGEST	create a tdigest by merging multiple tdigests together
HISTOGRAM	compute frequency of each element
MERGE_HISTOGRAM	merge partial values of HISTOGRAM aggregation,

Definition at line 85 of file aggregation.hpp.

Constructor & Destructor Documentation

aggregation()

cudf::aggregation::aggregation ( aggregation::Kind  a )

inline

Construct a new aggregation object.

Parameters

a	aggregation::Kind enum value

Definition at line 131 of file aggregation.hpp.

Member Function Documentation

clone()

virtual std::unique_ptr<aggregation> cudf::aggregation::clone ( ) const

pure virtual

Clones the aggregation object.

Returns

A copy of the aggregation object

do_hash()

virtual size_t cudf::aggregation::do_hash ( ) const

inlinevirtual

Computes the hash value of the aggregation.

Returns

The hash value of the aggregation

Definition at line 148 of file aggregation.hpp.

finalize()

virtual void cudf::aggregation::finalize ( cudf::detail::aggregation_finalizer &  finalizer ) const

pure virtual

Compute the aggregation after pre-requisite simple aggregations have been computed.

Parameters

finalizer

The finalizer visitor pattern to use to compute the aggregation

get_simple_aggregations()

virtual std::vector<std::unique_ptr<aggregation> > cudf::aggregation::get_simple_aggregations ( data_type  col_type, cudf::detail::simple_aggregations_collector &  collector  ) const

pure virtual

Get the simple aggregations that this aggregation requires to compute.

Parameters

col_type	The type of the column to aggregate
collector	The collector visitor pattern to use to collect the simple aggregations

Returns

Vector of pre-requisite simple aggregations

is_equal()

virtual bool cudf::aggregation::is_equal ( aggregation const &  other ) const

inlinevirtual

Compares two aggregation objects for equality.

Parameters

other

The other aggregation to compare with

Returns

True if the two aggregations are equal

Definition at line 141 of file aggregation.hpp.

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The documentation for this class was generated from the following file:

• aggregation.hpp