Public Types | Public Member Functions | Static Public Attributes | List of all members
cudf::tdigest::tdigest_column_view Class Reference

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

Inheritance diagram for cudf::tdigest::tdigest_column_view:
cudf::column_view

Public Types

using offset_iterator = offset_type const *
 

Public Member Functions

 tdigest_column_view (column_view const &col)
 
 tdigest_column_view (tdigest_column_view &&tdigest_view)=default
 
 tdigest_column_view (const tdigest_column_view &tdigest_view)=default
 
tdigest_column_viewoperator= (tdigest_column_view const &)=default
 
tdigest_column_viewoperator= (tdigest_column_view &&)=default
 
column_view parent () const
 Returns the parent column.
 
lists_column_view centroids () const
 Returns the column of centroids.
 
column_view means () const
 Returns the internal column of mean values.
 
column_view weights () const
 Returns the internal column of weight values.
 
auto size_begin () const
 Returns an iterator that returns the size of each tdigest in the column (each row is 1 digest)
 
double const * min_begin () const
 Returns the first min value for the column. Each row corresponds to the minimum value for the accompanying digest.
 
double const * max_begin () const
 Returns the first max value for the column. Each row corresponds to the maximum value for the accompanying digest.
 

Static Public Attributes

static constexpr size_type mean_column_index {0}
 
static constexpr size_type weight_column_index {1}
 
static constexpr size_type centroid_column_index {0}
 
static constexpr size_type min_column_index {1}
 
static constexpr size_type max_column_index {2}
 

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 59 of file tdigest_column_view.cuh.


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