[ https://issues.apache.org/jira/browse/NIFI-12389?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Matt Burgess reassigned NIFI-12389: ----------------------------------- Assignee: Matt Burgess > Add variance and standard deviation to AttributeRollingWindow > ------------------------------------------------------------- > > Key: NIFI-12389 > URL: https://issues.apache.org/jira/browse/NIFI-12389 > Project: Apache NiFi > Issue Type: Improvement > Components: Extensions > Reporter: Matt Burgess > Assignee: Matt Burgess > Priority: Major > > AttributeRollingWindow currently uses state to calculate metrics like sum, > count, and mean (average) for a rolling time window (optionally using > sub-windows to use smaller aggregates to estimate metrics for a larger total > time window as it stores the window values in state). > Variance and its positive square root (standard deviation) are other helpful > univariate statistics. Using "online" algorithms such as Welford's method > adds no extra memory requirement and runs in constant time. Apache Commons > Math3 has such an implementation and could be used to add attributes to the > FlowFile for variance and standard deviation. These metrics can be used for > filtering out noise downstream, for example RouteOnAttribute and/or stateful > UpdateAttribute where the current attribute value is more than 2 standard > deviations away from the mean. -- This message was sent by Atlassian Jira (v8.20.10#820010)