BiasEstimator (searchlib 7.501.17 API)

java.lang.Object
- com.yahoo.searchlib.aggregation.hll.BiasEstimator

```
public class BiasEstimator
extends Object
```
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

- Constructor Summary
  
  Constructors
  Constructor Description
  
  BiasEstimator(int precision)
  Constructs the BiasEstimator for a given HLL precision.
- Method Summary
  
  All Methods Instance Methods Concrete Methods
  Modifier and Type Method Description
  
  double estimateBias(double rawEstimate)
  Maps a given raw estimate to a bias correction value.
  - Methods inherited from class java.lang.Object
    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - BiasEstimator
```
public BiasEstimator(int precision)
```
    Constructs the BiasEstimator for a given HLL precision.
    
    Parameters:
    
    precision - HLL precision
- Method Detail
  - 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.