UK Data AtlasAPI

Measure how two areas overlap

See how much two areas overlap, even across different geographies such as a constituency and a local authority, without downloading either shape. You get the shared area, each side's share of it and a plain relation like within or overlaps.

get
/areas/{geography}/{release}/{code}/overlap

Path parameters

  • geographystringrequired

    A geography type id, e.g. constituency or ward.

  • releasestringrequired

    A boundary release id, e.g. 2024-07-uk-bgc, or latest for the geography's newest release: the one /boundary-releases:resolve chooses for the furthest date. A response to latest names the release it read in Content-Location. A geography whose newest month holds several releases that differ in more than coverage, or that has a release whose id carries no month, is refused with 409 and the releases that could be newest.

  • codestringrequired

    An area's official code in that release, e.g. E05000932.

Query parameters

  • placestringrequired

    The other area as {geography}/{release}/{code}, such as localAuthority/2024-05-uk-bgc/E07000092. Use latest as the release for its newest unambiguous published boundary release.

Returns

Envelope

Both areas, the overlap, its relation and the method.

  • apiVersionv1required
  • atlasReleasestringrequired

    The immutable /atlas-release releaseId for the artifacts that produced this response.

  • metaobjectrequired
    Show1 child field
    • nextCursorstring | nullrequired

      Opaque cursor for the next page, or null at the end.

When it goes wrong

  • 400A query parameter is malformed or its cursor is not valid for this result set.
  • 404No resource matches that identity.
  • 503The referenced build artifact has not been built yet.

Every error has the same shape. See Errors for how to handle them.

Technical notes

Show the precise behaviour

Intersects this area with the area named in place, which may be of another geography or boundary release, and returns the shared area, each area's share of it, and a relation, so a constituency and a local authority can be compared without downloading either geometry. The relation follows the rules the published area-overlap crosswalks are compiled with, stated in method. The intersection is judged by its widest piece: narrower than sliverWidthM it is where two independently generalised borders disagree, and the relation is boundary-only; within a factor of two of that width it is indeterminate, because a crosswalk compile would refuse to decide. Otherwise an area covered to minimumCoverage is within the other, the other contains it, both covered is same-extent, and anything else overlaps. Areas that do not meet are disjoint. This measures the generalised boundaries as published and is not an official statement of how the areas relate. publishedRelationships lists any published crosswalk relationship between the two, with its method and quality. The other release may be latest; the response records that selection beside the second area.