processing

CORE

This module contains functions that computes new geographies by processing existing geographies.

ST_DELAUNAYLINES

ST_DELAUNAYLINES(points)

Description

Calculates the Delaunay triangulation of the points provided. A MultiLineString object is returned.

• points: GEOMETRY MultiPoint input to the Delaunay triangulation.

warning

The maximum number of points typically used to compute Delaunay diagrams is 300,000. This limit ensures efficient computation while maintaining accuracy in delineating regions based on proximity to specified points.

Return type

VARCHAR(MAX)

Example

SELECT carto.ST_DELAUNAYLINES(
  ST_GEOMFROMTEXT(
    'MULTIPOINT((-70.3894720672732 42.9988854818585),(-71.1048188482079 42.6986831053718),(-72.6818783178395 44.1191152795997),(-73.8221894711314 35.1057463244819))'
  )
);
-- {"type": "MultiLineString", "coordinates": [[[-71.1048188482, 42.6986831054], [-70.3894720673, 42.9988854819], [-73.8221894711, 35.1057463245], [-71.1048188482, 42.6986831054]], ...

ST_DELAUNAYPOLYGONS

ST_DELAUNAYPOLYGONS(points)

Description

Calculates the Delaunay triangulation of the points provided. A MultiPolygon object is returned.

• points: GEOMETRY MultiPoint input to the Delaunay triangulation.

warning

The maximum number of points typically used to compute Delaunay diagrams is 300,000. This limit ensures efficient computation while maintaining accuracy in delineating regions based on proximity to specified points.

Return type

VARCHAR(MAX)

Example

SELECT carto.ST_DELAUNAYPOLYGONS(
  ST_GEOMFROMTEXT(
    'MULTIPOINT((-70.3894720672732 42.9988854818585),(-71.1048188482079 42.6986831053718),(-72.6818783178395 44.1191152795997),(-73.8221894711314 35.1057463244819))'
  )
);
-- {"type": "MultiPolygon", "coordinates": [[[[-71.1048188482, 42.6986831054], [-70.3894720673, 42.9988854819], [-73.8221894711, 35.1057463245], [-71.1048188482, 42.6986831054]]], ...

ST_POLYGONIZE

ST_POLYGONIZE(lines)

Description

Creates a polygon from a geography which contains lines that represent its edges.

• line: GEOMETRY lines which represent the polygon edges.

Return type

GEOMETRY

Example

SELECT carto.ST_POLYGONIZE(
  ST_GEOMFROMTEXT(
    'LINESTRING(-74.5366825512491 43.6889777784079, -70.7632814028801 42.9679602005825, -70.2005131676838 43.8455720129728, -74.5366825512491 43.6889777784079)'
  )
);
-- POLYGON ((-74.5366825512491 43.6889777784079, -70.7632814028801 42.9679602005825, -70.2005131676838 43.8455720129728, -74.5366825512491 43.6889777784079))

ST_VORONOILINES

ST_VORONOILINES(points)

Description

Calculates the Voronoi diagram of the points provided. A MultiLineString object is returned.

• points: GEOMETRY MultiPoint input to the Voronoi diagram.

warning

The maximum number of points typically used to compute Voronoi diagrams is 300,000. This limit ensures efficient computation while maintaining accuracy in delineating regions based on proximity to specified points.

Return type

VARCHAR(MAX)

Example

SELECT carto.ST_VORONOILINES(
  ST_GEOMFROMTEXT(
    'MULTIPOINT((-74.5366825512491 43.6889777784079),(-74.4821382017478 43.3096147774153),(-70.7632814028801 42.9679602005825))'
  )
);
-- {"type": "MultiLineString", "coordinates": [[[-72.563891028, 43.7790206765], [-72.6715241053, 42.6074514117]], [[-72.563891028, 43.7790206765], ...

ST_VORONOIPOLYGONS

ST_VORONOIPOLYGONS(points)

Description

Calculates the Voronoi diagram of the points provided. A MultiPolygon object is returned.

• points: GEOMETRY MultiPoint input to the Voronoi diagram.

warning

The maximum number of points typically used to compute Voronoi diagrams is 300,000. This limit ensures efficient computation while maintaining accuracy in delineating regions based on proximity to specified points.

Return type

VARCHAR(MAX)

Example

SELECT carto.ST_VORONOIPOLYGONS(
  ST_GEOMFROMTEXT(
    'MULTIPOINT((-74.5366825512491 43.6889777784079),(-74.4821382017478 43.3096147774153),(-70.7632814028801 42.9679602005825))'
  )
);
-- {"type": "MultiPolygon", "coordinates": [[[[-74.8971913401, 43.443541604], [-72.563891028, 43.7790206765], [-72.5122106861, 44.0494865673], [-74.8971913401, 44.0494865673], ...