HADOOP-8866. SampleQuantiles#query is O(N^2) instead of O(N). Contributed by Andrew Wang.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1391712 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Aaron Myers 2012-09-29 01:00:05 +00:00
parent d95daf370d
commit 288e052acd
2 changed files with 8 additions and 2 deletions

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@ -27,6 +27,9 @@ Release 2.0.3-alpha - Unreleased
OPTIMIZATIONS
HADOOP-8866. SampleQuantiles#query is O(N^2) instead of O(N). (Andrew Wang
via atm)
BUG FIXES
HADOOP-8795. BASH tab completion doesn't look in PATH, assumes path to

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@ -210,9 +210,12 @@ public class SampleQuantiles {
int rankMin = 0;
int desired = (int) (quantile * count);
ListIterator<SampleItem> it = samples.listIterator();
SampleItem prev = null;
SampleItem cur = it.next();
for (int i = 1; i < samples.size(); i++) {
SampleItem prev = samples.get(i - 1);
SampleItem cur = samples.get(i);
prev = cur;
cur = it.next();
rankMin += prev.g;