[SERVER-5044] $stdDev aggregation operator for standard deviation Created: 22/Feb/12 Updated: 06/Jan/19 Resolved: 16/Jun/15 |
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| Status: | Closed |
| Project: | Core Server |
| Component/s: | Aggregation Framework |
| Affects Version/s: | None |
| Fix Version/s: | 3.1.5 |
| Type: | New Feature | Priority: | Major - P3 |
| Reporter: | Mathias Stearn | Assignee: | Mathias Stearn |
| Resolution: | Done | Votes: | 25 |
| Labels: | pull-request | ||
| Remaining Estimate: | Not Specified | ||
| Time Spent: | Not Specified | ||
| Original Estimate: | Not Specified | ||
| Issue Links: |
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| Backwards Compatibility: | Fully Compatible | ||||||||||||||||||||||||
| Sprint: | Quint Iteration 4, Quint Iteration 5 | ||||||||||||||||||||||||
| Participants: | |||||||||||||||||||||||||
| Case: | (copied to CRM) | ||||||||||||||||||||||||
| Linked BF Score: | 0 | ||||||||||||||||||||||||
| Description |
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see https://gist.github.com/1886960 for an algorithm to handle calculating standard deviation and variance across many servers. |
| Comments |
| Comment by Githook User [ 10/Jun/15 ] |
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Author: {u'username': u'RedBeard0531', u'name': u'Mathias Stearn', u'email': u'mathias@10gen.com'}Message: |
| Comment by Githook User [ 09/Jun/15 ] |
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Author: {u'username': u'RedBeard0531', u'name': u'Mathias Stearn', u'email': u'mathias@10gen.com'}Message: |
| Comment by Himanshu Jain [ 03/Feb/15 ] |
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Hey, It's a nice to have feature. |
| Comment by Kevin Davenport [X] [ 16/Jan/14 ] |
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This is a must have. |
| Comment by auto [ 21/Oct/13 ] |
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Author: {u'username': u'RedBeard0531', u'name': u'Mathias Stearn', u'email': u'mathias@10gen.com'}Message: Clean up AccumulatorAvg Major change is not inheriting from AccumulatorSum Prep for |
| Comment by Michael Svendsen [ 27/Jul/13 ] |
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I opened a pull request for this today. https://github.com/mongodb/mongo/pull/464 This implements standard deviation and variance calculations using the algorithm listed in the description. |
| Comment by Ranjith Ramachandra [ 12/Jul/13 ] |
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Any idea if this will be picked up at all? |
| Comment by Matt Kangas [ 08/Jul/13 ] |
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Closed https://github.com/mongodb/mongo/pull/409 due to inactivity |
| Comment by Justin [ 04/Apr/13 ] |
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I started this today. Here is the commit in github. https://github.com/base698/mongo/commit/2f9ab97ffb6f027faf4c503ba4a58e500eb6fb23 It needs tests and variance. It probably could be refactored to do average, variance and standard deviation in one motion since you have to do it incrementally. |
| Comment by Mathias Stearn [ 27/Feb/12 ] |
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Correct. Ideally any $group op should be usable in a $project against an array field, but that is a different issue. |
| Comment by Chris Westin [ 22/Feb/12 ] |
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I'm assuming this is meant to be for $group. |