Given a column_view containing tdigest data, an instance of this class provides a wrapper on the compound column for tdigest operations. More...

#include <tdigest_column_view.hpp>

Inheritance diagram for cudf::tdigest::tdigest_column_view:

Public Types
using	offset_iterator = size_type const *
	Iterator over offsets.

Public Member Functions
	tdigest_column_view (column_view const &)
	Construct tdigest_column_view from a column_view.

	tdigest_column_view (tdigest_column_view &&)=default
	Move constructor.

	tdigest_column_view (tdigest_column_view const &)=default
	Copy constructor.

tdigest_column_view &	operator= (tdigest_column_view const &)=default
	Copy assignment operator. More...

tdigest_column_view &	operator= (tdigest_column_view &&)=default
	Move assignment operator. More...

column_view	parent () const
	Returns the parent column. More...

lists_column_view	centroids () const
	Returns the column of centroids. More...

column_view	means () const
	Returns the internal column of mean values. More...

column_view	weights () const
	Returns the internal column of weight values. More...

double const *	min_begin () const
	Returns the first min value for the column. Each row corresponds to the minimum value for the accompanying digest. More...

double const *	max_begin () const
	Returns the first max value for the column. Each row corresponds to the maximum value for the accompanying digest. More...

Static Public Attributes
static constexpr size_type	mean_column_index {0}
	Mean column index.

static constexpr size_type	weight_column_index {1}
	Weight column index.

static constexpr size_type	centroid_column_index {0}
	Centroid column index.

static constexpr size_type	min_column_index {1}
	Min column index.

static constexpr size_type	max_column_index {2}
	Max column index.

Detailed Description

Given a column_view containing tdigest data, an instance of this class provides a wrapper on the compound column for tdigest operations.

A tdigest is a "compressed" set of input scalars represented as a sorted set of centroids (https://arxiv.org/pdf/1902.04023.pdf). This data can be queried for quantile information. Each row in a tdigest column represents an entire tdigest.

The column has the following structure:

struct { // centroids for the digest list { struct { double // mean double // weight } } // these are from the input stream, not the centroids. they are used // during the percentile_approx computation near the beginning or // end of the quantiles double // min double // max }

Definition at line 57 of file tdigest_column_view.hpp.

Member Function Documentation

◆ centroids()

lists_column_view cudf::tdigest::tdigest_column_view::centroids ( ) const

Returns the column of centroids.

Returns: The list column of centroids

◆ max_begin()

double const* cudf::tdigest::tdigest_column_view::max_begin ( ) const

Returns the first max value for the column. Each row corresponds to the maximum value for the accompanying digest.

Returns: const pointer to the first max value for the column

◆ means()

column_view cudf::tdigest::tdigest_column_view::means ( ) const

Returns the internal column of mean values.

Returns: The internal column of mean values

◆ min_begin()

double const* cudf::tdigest::tdigest_column_view::min_begin ( ) const

Returns the first min value for the column. Each row corresponds to the minimum value for the accompanying digest.

Returns: const pointer to the first min value for the column

◆ operator=() [1/2]

tdigest_column_view& cudf::tdigest::tdigest_column_view::operator= ( tdigest_column_view && )

default

Move assignment operator.

Returns: this object after moving the contents of the other object (transfer ownership)

◆ operator=() [2/2]

tdigest_column_view& cudf::tdigest::tdigest_column_view::operator= ( tdigest_column_view const & )

default

Copy assignment operator.

Returns: this object after copying the contents of the other object (copy)

◆ parent()

column_view cudf::tdigest::tdigest_column_view::parent ( ) const

Returns the parent column.

Returns: The parent column

◆ weights()

column_view cudf::tdigest::tdigest_column_view::weights ( ) const

Returns the internal column of weight values.

Returns: The internal column of weight values

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

tdigest_column_view.hpp

Public Types

Public Member Functions

Static Public Attributes