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nichunen updated KYLIN-3361: ---------------------------- Parent: (was: KYLIN-3358) Issue Type: Improvement (was: Sub-task) > Support stddev as a new measure > ------------------------------- > > Key: KYLIN-3361 > URL: https://issues.apache.org/jira/browse/KYLIN-3361 > Project: Kylin > Issue Type: Improvement > Reporter: Zhong Yanghong > Assignee: Zhong Yanghong > Priority: Major > Fix For: v3.1.0 > > > (x ~1~ - +x+) ^2^ + (x ~2~ - +x+) ^2^ + ... + (x ~n~ - +x+) ^2^ = x ~1~ ^2^ + > x ~2~ ^2^ + ... + x ~n~ ^2^ - n +x+ ^2^, where +x+ is the average of x ~1~, x > ~2~, ..., x ~n~. Therefore, to compute stddev, what kylin need to do is to > pre-calculate sum(x ~i~ ^2^), sum(x ~i~) and count -- This message was sent by Atlassian Jira (v8.3.4#803005)