README
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LogLog-Beta 
LogLog-Beta and More: A New Algorithm for Cardinality Estimation Based on LogLog Counting - by Jason Qin, Denys Kim, Yumei Tung
TL;DR: Better than HyperLogLog in approximating the number unique elements in a set
LogLog-Beta
LogLog-Beta is a new algorithm for estimating cardinalities based on LogLog counting. The new algorithm uses only one formula and needs no additional bias corrections for the entire range of cardinalities, therefore, it is more efficient and simpler to implement. The simulations show that the accuracy provided by the new algorithm is as good as or better than the accuracy provided by either of HyperLogLog or HyperLogLog++.
Using LogLog-Beta
// Create LogLogBeta
llb := loglogbeta.NewDefault()
// Add value to LogLogBeta
llb.Add([]byte("hello"))
// Returns cardinality
llb.Cardinality()
Initial Results
From demo
file: data/words-1
exact: 150
estimate: 157
ratio: 4.458599%
file: data/words-2
exact: 1308
estimate: 1373
ratio: 4.734159%
file: data/words-3
exact: 76205
estimate: 78440
ratio: 2.849312%
file: data/words-4
exact: 235886
estimate: 236587
ratio: 0.296297%
file: data/words-5
exact: 349900
estimate: 349388
ratio: -0.146542%
file: data/words-6
exact: 479829
estimate: 481224
ratio: 0.289886%
total
exact: 660131
estimate: 660548
ratio: 0.063129%
Documentation
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Index ¶
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type LogLogBeta ¶
type LogLogBeta struct {
// contains filtered or unexported fields
}
LogLogBeta is a sketch for cardinality estimation based on LogLog counting
func (*LogLogBeta) Add ¶
func (llb *LogLogBeta) Add(value []byte)
Add inserts a value into the sketch
func (*LogLogBeta) Cardinality ¶
func (llb *LogLogBeta) Cardinality() uint64
Cardinality returns the number of unique elements added to the sketch
func (*LogLogBeta) MarshalBinary ¶
func (llb *LogLogBeta) MarshalBinary() (data []byte, err error)
MarshalBinary implements the encoding.BinaryMarshaler interface.
func (*LogLogBeta) Merge ¶
func (llb *LogLogBeta) Merge(other *LogLogBeta)
Merge takes another LogLogBeta and combines it with llb one, making llb the union of both.
func (*LogLogBeta) UnmarshalBinary ¶
func (llb *LogLogBeta) UnmarshalBinary(data []byte) error
UnmarshalBinary implements the encoding.BinaryUnmarshaler interface.
Source Files
Directories