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Are s_Covers and s_CoveredBy really standard spatial relations? #39
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Good catch @nicolas-heigvd . s_Covers and s_CoveredBy are not defined. |
covers() and coveredBy() are not defined in Simple Features Access, but they are part of the Dimensionally Extended 9-Intersection Model (DE-9IM). As noted on that Wikipedia page:
We should indeed file a change request to have them added to SFA. We had a similar discussion in CQL2, but decided to not add them yet. @ghobona Where should we file a change request for SFA? |
Maybe there should be a Cross-SWG discussion of full vs partial implementations, and non-canonical ("unnormalised") versions of the Allen Agebra, 4-Intersections and DE-9IM? The W3C Time Ontology has the full set of Allen relationships (13) , in one dimension, but there were practical real-world needs to augment them with easy-to-use (non-canonical) combinations. |
If I understand correctly, one can easily implement Covers() and ContainsBy() using the Relate() method already defined in Simple Features Access as follows:
|
Hello,
As stated in your draft, are
s_Covers
ands_CoveredBy
really standard spatial relations?styles-and-symbology/core/sections/clause_18_functions.adoc
Lines 79 to 80 in d136661
If yes, where are they defined?
Because the OGC SFA only specify the following:
So maybe it's worth discussing an update to the OGC SFA before integrating them here?
Who is in charge for such updates, if needed?
Thanks for your answer.
Warm Regards.
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