org.elasticsearch.exponentialhistogram.ExponentialHistogramQuantile

public class ExponentialHistogramQuantile extends Object

Provides quantile estimation for ExponentialHistogram instances. All algorithms assume that the values of each histogram bucket have exactly the same value, which is defined by ExponentialScaleUtils.getPointOfLeastRelativeError(long, int).

Constructor Details
- ExponentialHistogramQuantile
  
  public ExponentialHistogramQuantile()
Method Details
- getQuantile
  
  public static double getQuantile(ExponentialHistogram histo, double quantile)
  
  Estimates a quantile for the distribution represented by the given histogram. It returns the value of the element at rank max(0, min(n - 1, (quantile * (n + 1)) - 1)), where n is the total number of values and rank starts at 0. If the rank is fractional, the result is linearly interpolated from the values of the two neighboring ranks. The result is clamped to the histogram's minimum and maximum values.
  
  Parameters:
  
  histo - the histogram representing the distribution
  
  quantile - the quantile to query, in the range [0, 1]
  
  Returns:
  
  the estimated quantile value, or Double.NaN if the histogram is empty
- estimateRank
  
  public static long estimateRank(ExponentialHistogram histo, double value, boolean inclusive)
  
  Estimates the rank of a given value in the distribution represented by the histogram. In other words, returns the number of values which are less than (or less-or-equal, if inclusive is true) the provided value.
  
  Parameters:
  
  histo - the histogram to query
  
  value - the value to estimate the rank for
  
  inclusive - if true, counts values equal to the given value as well
  
  Returns:
  
  the number of elements less than (or less-or-equal, if inclusive is true) the given value

Class ExponentialHistogramQuantile

Constructor Summary