[ https://issues.apache.org/jira/browse/LUCENE-4550?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
David Smiley reassigned LUCENE-4550: ------------------------------------ Assignee: David Smiley > For extremely wide shapes (> 180 degrees) distErrPct is not used correctly > -------------------------------------------------------------------------- > > Key: LUCENE-4550 > URL: https://issues.apache.org/jira/browse/LUCENE-4550 > Project: Lucene - Core > Issue Type: Bug > Components: modules/spatial > Affects Versions: 4.0 > Reporter: David Smiley > Assignee: David Smiley > Priority: Minor > Attachments: LUCENE-4550__fix_SpatialArgs_calcDistanceFromErrPct.patch > > > When a shape is given to a PrefixTreeStrategy (index or query time), it needs > to know how many levels down the prefix tree to go for a target precision > (distErrPct). distErrPct is basically a fraction of the radius of the shape, > defaulting to 2.5% (0.0025). > If the shape presented is extremely wide, > 180 degrees, then the internal > calculations in SpatialArgs.calcDistanceFromErrPct(...) will wrongly measure > the shape's size as having width < 180 degrees, yielding *more* accuracy than > intended. Given that this happens for unrealistic shape sizes and results in > more accuracy, I am flagging this as "minor", but a bug nonetheless. Indeed, > this was discovered as a result of someone using lucene-spatial incorrectly, > not for an actual shape they have. But in the extreme \[erroneous\] case > they had, they had 566k terms (!) generated, when it should have been ~1k > tops. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org