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1a4ceb1680
The new 'boundary(...)' function returns a geometry's topological boundary, ie for polygons this is a multilinestring representing the polygons rings
9 lines
620 B
Plaintext
9 lines
620 B
Plaintext
{
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"name": "boundary",
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"type": "function",
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"description":"Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry). For instance, a polygon geometry will have a boundary consisting of the linestrings for each ring in the polygon. Some geometry types do not have a defined boundary, eg points or geometry collections, and will return null.",
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"arguments": [ {"arg":"geometry","description":"a geometry"} ],
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"examples": [ { "expression":"geom_to_wkt(boundary(geom_from_wkt('Polygon((1 1, 0 0, -1 1, 1 1))')))", "returns":"'LineString(1 1,0 0,-1 1,1 1)'"}]
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}
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