Opened 11 years ago
Closed 11 years ago
#620 closed defect (wontfix)
Incorrect intersection between geometries
| Reported by: | rhf | Owned by: | |
|---|---|---|---|
| Priority: | major | Milestone: | 3.3.9 |
| Component: | Default | Version: | 3.3.7 |
| Severity: | Unassigned | Keywords: | |
| Cc: |
Description
I have two polylines A, B which partly overlap.
When computing the intersection C = intersection(A, B), geos reports the correct result, which is a simple linestring with two points. One of them is a noded intersection. The other one is not.
Hereafter I compute D = intersection(B, C). Of course D should equal C. Instead I will only get a single point: the noded intersection.
This seems strange to me: either I would expect C also to be incorrect or both queries to give the same result. The same issue occurs when I try to compute B - C.
With similar cases involving a noded and none-noded intersection, I get the correct results in all cases. For example when trying to reproduce the issue with simple horizontal lines.
I have attached to small files in WKB format: A.txt, B.txt to be used as input to reproduce the issue. Actually the original polygons used as input where much larger, but I was able to reduce their sizes such that they only have a few points. Also I am working with geos via Spatialite, but I do not think this is relevant for this issue.
Attachments (2)
Change History (3)
by , 11 years ago
comment:1 by , 11 years ago
| Resolution: | → wontfix |
|---|---|
| Status: | new → closed |
In general JTS/GEOS overaly operations do not obey the mathematical axioms of pure set theory.
See D7 in the JTS FAQ:
polyline A