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From Ken Geis <>
Subject [math] inefficient percentile implementation
Date Mon, 15 Nov 2004 00:11:34 GMT
The docs for org.apache.commons.math.stat.descriptive.rank.Percentile 
state that "To compute percentiles, the data must be (totally) ordered." 
  This is flat out wrong.  Sorting first with quicksort leads to O(n lg 
n) time, and there are selection algorithms for selection that are O(n). 
  Details can be found in the standard texts such as Introduction To 
Algorithms or Numerical Recipes.

If no one else cares to implement this, I certainly will within the next 
several weeks.

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