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https://issues.apache.org/jira/browse/SEDONA-178?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17618173#comment-17618173
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Jia Yu commented on SEDONA-178:
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[~umartin] Thanks for the great suggestion.
My thoughts are as follows:
# Option 1: this is OK since it introduces the minimal change but it is a
breaking change to some users.
# Option 2: Buffered Geometry does not sound like a valid solution.
# Option 3: I like this solution. But do we really need the margin? Because
the margin cannot be a fixed value since different CRS leads to different
margin. If the edge cases are extremely rare, maybe we can go without margin?
# Option 4: Prepared Geometry sounds like a ultimate solution but it requires
some major changes. I am not sure if anyone'd like to take care of this part...
> Correctness issue in distance join queries
> ------------------------------------------
>
> Key: SEDONA-178
> URL: https://issues.apache.org/jira/browse/SEDONA-178
> Project: Apache Sedona
> Issue Type: Bug
> Reporter: Martin Andersson
> Priority: Major
>
> Hi,
> We are seeing erroneous results for some distance join queries.
>
> Case 1:
> The following query gives no output even though the distance between the
> geometries is 1.
> {{select *}}
> {{from (select ST_LineFromText('Linestring(1 1, 1 4)') as geom) a}}
> {{join (select st_point(1.0,5.0) as geom) b}}
> {{on st_distance(a.geom, b.geom) < 1.4}}
> I think the issue boils down to a misuse of/error in Circle class.
> DistanceJoinExec.scala:60 will create a Circle from the linestring and a
> radius of 1.4.
> Circle will compute the center point (1 2.5) and radius (1.5) for the
> linestring. The actual radius used is max(radius(linestring), 1.4). See
> Circle.java:80
> For the query to work the Circle needs a radius 1.4 _larger_ than the
> linestring. Like this:
> circle = new Circle(geom, 0.0);
> circle.setRadius(circle.getRadius() + 1.4)
>
> Case 2:
> The following query matches the geometries even though the distance is not
> less than 0.1. Actual distance is 1.
> {{select *}}
> {{from (select ST_LineFromText('Linestring(1 1, 1 3, 3 3)') as geom) a}}
> {{join (select st_point(2.0,2.0) as geom) b}}
> {{on st_distance(a.geom, b.geom) < 0.1}}
> Pseudo code for the join condition:
> new Circle(a.geom, 0.1).covers(b.geom)
> The circle does cover the point but the linestring is further away from the
> point than 0.1
>
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