[
https://issues.apache.org/jira/browse/SPARK-33678?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Hyukjin Kwon resolved SPARK-33678.
----------------------------------
Fix Version/s: 3.2.0
Resolution: Fixed
Issue resolved by pull request 30745
[https://github.com/apache/spark/pull/30745]
> Numerical product aggregation
> -----------------------------
>
> Key: SPARK-33678
> URL: https://issues.apache.org/jira/browse/SPARK-33678
> Project: Spark
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 2.4.7, 3.0.0, 3.1.0
> Reporter: Richard Penney
> Assignee: Richard Penney
> Priority: Minor
> Fix For: 3.2.0
>
>
> There is currently no facility in {{spark.sql.functions}} to allow
> computation of the product of all numbers in a grouping expression. Such a
> facility would likely be useful when computing statistical quantities such as
> the combined probability of a set of independent events, or in financial
> applications when calculating a cumulative interest rate.
> Although it is certainly possible to emulate this by an expression of the
> form {{exp(sum(log(column)))}}, this has a number of significant drawbacks:
> * It involves computationally costly functions (exp, log)
> * It is more verbose than something like {{product(column)}}
> * It is more prone to numerical inaccuracies when handling quantities that
> are close to one than by directly multiplying a set of numbers
> * It will not handle zeros or negative numbers cleanly
> I am currently developing an addition to {{sql.functions}}, which involves [a
> new Catalyst aggregation
> expression|https://github.com/rwpenney/spark/blob/feature/agg-product/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/aggregate/Product.scala].
> This needs some additional testing, and I hope to issue a pull-request soon.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscr...@spark.apache.org
For additional commands, e-mail: issues-h...@spark.apache.org
