simple

Documentation

Overview

Package simple implements an unweighted reservoir sampling algorithm.

Index

• type Simple
  • func New[T any](capacity int, rnd *rand.Rand) *Simple[T]
  • func (s *Simple[T]) Add(item T)
  • func (s *Simple[T]) Count() int
  • func (s *Simple[T]) Get(i int) T
  • func (s *Simple[T]) Init(capacity int, rnd *rand.Rand)
  • func (s *Simple[T]) Size() int

Types

type Simple

type Simple[T any] struct {
	// contains filtered or unexported fields
}

Simple implements unweighted reservoir sampling using Algorithm R from "Random sampling with a reservoir" by Jeffrey Vitter (1985) https://en.wikipedia.org/wiki/Reservoir_sampling#Algorithm_R

func New

func New[T any](capacity int, rnd *rand.Rand) *Simple[T]

New returns a simple reservoir sampler with given capacity (i.e., reservoir size) and random number generator.

func (*Simple[T]) Add

func (s *Simple[T]) Add(item T)

Add considers a new observation for the sample. Items have unit weight.

func (*Simple[T]) Count

func (s *Simple[T]) Count() int

Count returns the number of items that were observed.

func (*Simple[T]) Get

func (s *Simple[T]) Get(i int) T

Get returns the i'th selected item from the sample.

func (*Simple[T]) Init

func (s *Simple[T]) Init(capacity int, rnd *rand.Rand)

func (*Simple[T]) Size

func (s *Simple[T]) Size() int

Size returns the number of items in the sample. If the reservoir is full, Size() equals Capacity().