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Anton Mushin commented on FLINK-3613: ------------------------------------- Hello everyone. Do FLINK-4604 extends this issue? or is FLINK-4604 part of this issue for flink sql? > Add standard deviation, mean, variance to list of Aggregations > -------------------------------------------------------------- > > Key: FLINK-3613 > URL: https://issues.apache.org/jira/browse/FLINK-3613 > Project: Flink > Issue Type: Improvement > Reporter: Todd Lisonbee > Priority: Minor > Attachments: DataSet-Aggregation-Design-March2016-v1.txt > > > Implement standard deviation, mean, variance for > org.apache.flink.api.java.aggregation.Aggregations > Ideally implementation should be single pass and numerically stable. > References: > "Scalable and Numerically Stable Descriptive Statistics in SystemML", Tian et > al, International Conference on Data Engineering 2012 > http://dl.acm.org/citation.cfm?id=2310392 > "The Kahan summation algorithm (also known as compensated summation) reduces > the numerical errors that occur when adding a sequence of finite precision > floating point numbers. Numerical errors arise due to truncation and > rounding. These errors can lead to numerical instability when calculating > variance." > https://en.wikipedia.org/wiki/Kahan_summation_algorithm -- This message was sent by Atlassian JIRA (v6.3.4#6332)