Class BiasEstimator
java.lang.Object
com.yahoo.searchlib.aggregation.hll.BiasEstimator
Performs bias correction for a given precision and raw estimate.
The values are taken from Google's HLL++ paper:
https://docs.google.com/document/d/1gyjfMHy43U9OWBXxfaeG-3MjGzejW1dlpyMwEYAAWEI/view?fullscreen#
- Author:
- bjorncs
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Constructor Summary
ConstructorDescriptionBiasEstimator
(int precision) Constructs the BiasEstimator for a given HLL precision. -
Method Summary
Modifier and TypeMethodDescriptiondouble
estimateBias
(double rawEstimate) Maps a given raw estimate to a bias correction value.
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Constructor Details
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BiasEstimator
public BiasEstimator(int precision) Constructs the BiasEstimator for a given HLL precision.- Parameters:
precision
- HLL precision
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Method Details
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estimateBias
public double estimateBias(double rawEstimate) Maps a given raw estimate to a bias correction value. The callee should subtract the bias from the raw estimate to get a bias corrected HLL estimate. Uses linear interpolation when no exact value exist.- Parameters:
rawEstimate
- The raw HLL estimate- Returns:
- The estimated bias for the given raw estimate.
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