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Bug #8269

dtrace stddev aggregation is normalized incorrectly

Added by Andriy Gapon over 2 years ago. Updated over 2 years ago.

Status:
Closed
Priority:
Normal
Assignee:
-
Category:
DTrace
Start date:
2017-05-24
Due date:
% Done:

100%

Estimated time:
Difficulty:
Bite-size
Tags:
needs-triage

Description

It seems that currently normalization of stddev aggregation is done incorrectly.
We divide both the sum of values and the sum of their squares by the
normalization factor. But we should divide the sum of squares by the
normalization factor squared to scale the original values properly.

History

#2

Updated by Electric Monk over 2 years ago

  • Status changed from New to Closed
  • % Done changed from 0 to 100

git commit 79809f9cf402f130667349b2d4007ecd65d63c6f

commit  79809f9cf402f130667349b2d4007ecd65d63c6f
Author: Andriy Gapon <avg@FreeBSD.org>
Date:   2017-06-08T04:26:44.000Z

    8269 dtrace stddev aggregation is normalized incorrectly
    Reviewed by: Bryan Cantrill <bryan@joyent.com>
    Approved by: Robert Mustacchi <rm@joyent.com>

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