query-684feed5a9043067240b88aaf51e2e75

rq turtle/ttl

GIS; especially has-parts. (Q161779)spatial reference system Look at https://epsg.io/27700-7710. (P1338)EPSG CRS and (Q11902211)World Geodetic System 1984 For example, . (Q11210)coordinate system ; it is a subclass of (Q184876)frame of reference is only an instance of (Q161779)spatial reference system . (Q184876)frame of reference is both an instance and a subclass of (Q1502887)geodetic reference system as has-parts seems strained, but maybe it is right. If an instance, then it should have the properties. If a subclass, then each instance should have the property, and the property should be restricted to a specific value. A better way would be to point to a specific ellipsoid; something like the class X is based on this item. Ah, the problem is they are not properties but rather items! (Q65952201)inverse flattening and (Q171594)semi-major axis Handling

Use at

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT ?CRS ?CRSLabel WHERE {
  # a CRS
  # confusion about
  #   version of Q1502887
  #   instance of spatial reference system Q161779
  #   subclass of Q1502887
  ?CRS wdt:P31/wdt:P279* wd:Q161779 .

  SERVICE wikibase:label {
     bd:serviceParam wikibase:language "en" .
  }
}

Query found at

graph TD classDef projected fill:lightgreen; classDef literal fill:orange; classDef iri fill:yellow; v1("?CRS"):::projected a1((" ")) c5(["bd:serviceParam"]):::iri c3(["wd:Q161779"]):::iri c7(["en"]):::literal v1 --"wdt:P31"--> a1 a1 --"wdt:P279"--> c3 subgraph s1["http://wikiba.se/ontology#label"] style s1 stroke-width:4px; c5 --"wikibase:language"--> c7 end