base_theta_sketch_alloc< Allocator > Class Template Reference

Abstract base class for Theta sketch. More...

#include <theta_sketch.hpp>

Public Member Functions
virtual Allocator	get_allocator () const =0
virtual bool	is_empty () const =0
double	get_estimate () const
double	get_lower_bound (uint8_t num_std_devs) const
	Returns the approximate lower error bound given a number of standard deviations. More...
double	get_upper_bound (uint8_t num_std_devs) const
	Returns the approximate upper error bound given a number of standard deviations. More...
bool	is_estimation_mode () const
double	get_theta () const
virtual uint64_t	get_theta64 () const =0
virtual uint32_t	get_num_retained () const =0
virtual uint16_t	get_seed_hash () const =0
virtual bool	is_ordered () const =0
virtual string< Allocator >	to_string (bool print_items=false) const
	Provides a human-readable summary of this sketch as a string. More...

Detailed Description

template<typename Allocator = std::allocator<uint64_t>>
class datasketches::base_theta_sketch_alloc< Allocator >

Abstract base class for Theta sketch.

Member Function Documentation

get_allocator()

virtual Allocator get_allocator ( ) const

pure virtual

Returns

allocator

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

is_empty()

virtual bool is_empty ( ) const

pure virtual

Returns

true if this sketch represents an empty set (not the same as no retained entries!)

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

get_estimate()

double get_estimate

Returns

estimate of the distinct count of the input stream

get_lower_bound()

double get_lower_bound

(

uint8_t

num_std_devs

)

const

Returns the approximate lower error bound given a number of standard deviations.

This parameter is similar to the number of standard deviations of the normal distribution and corresponds to approximately 67%, 95% and 99% confidence intervals.

Parameters

num_std_devs

number of Standard Deviations (1, 2 or 3)

Returns

the lower bound

get_upper_bound()

double get_upper_bound

(

uint8_t

num_std_devs

)

const

Returns the approximate upper error bound given a number of standard deviations.

This parameter is similar to the number of standard deviations of the normal distribution and corresponds to approximately 67%, 95% and 99% confidence intervals.

Parameters

num_std_devs

number of Standard Deviations (1, 2 or 3)

Returns

the upper bound

is_estimation_mode()

bool is_estimation_mode

Returns

true if the sketch is in estimation mode (as opposed to exact mode)

get_theta()

double get_theta

Returns

theta as a fraction from 0 to 1 (effective sampling rate)

get_theta64()

virtual uint64_t get_theta64 ( ) const

pure virtual

Returns

theta as a positive integer between 0 and LLONG_MAX

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

get_num_retained()

virtual uint32_t get_num_retained ( ) const

pure virtual

Returns

the number of retained entries in the sketch

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

get_seed_hash()

virtual uint16_t get_seed_hash ( ) const

pure virtual

Returns

hash of the seed that was used to hash the input

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

is_ordered()

virtual bool is_ordered ( ) const

pure virtual

Returns

true if retained entries are ordered

Implemented in wrapped_compact_theta_sketch_alloc< Allocator >, compact_theta_sketch_alloc< Allocator >, and update_theta_sketch_alloc< Allocator >.

to_string()

string< A > to_string ( bool  print_items = false ) const

virtual

Provides a human-readable summary of this sketch as a string.

Parameters

print_items

if true include the list of items retained by the sketch

Returns

sketch summary as a string

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

• theta/include/theta_sketch.hpp
• theta/include/theta_sketch_impl.hpp