Function (Flink)
GeometryType¶
Introduction: Returns the type of the geometry as a string. Eg: 'LINESTRING', 'POLYGON', 'MULTIPOINT', etc. This function also indicates if the geometry is measured, by returning a string of the form 'POINTM'.
Format: GeometryType (A: Geometry)
Since: v1.5.0
Example:
SELECT GeometryType(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)'));
Result:
geometrytype
--------------
LINESTRING
SELECT GeometryType(ST_GeomFromText('POINTM(0 0 1)'));
Result:
geometrytype
--------------
POINTM
ST_3DDistance¶
Introduction: Return the 3-dimensional minimum cartesian distance between A and B
Format: ST_3DDistance (A: Geometry, B: Geometry)
Since: v1.3.0
Example:
SELECT ST_3DDistance(ST_GeomFromText("POINT Z (0 0 -5)"),
ST_GeomFromText("POINT Z(1 1 -6"))
Output:
1.7320508075688772
ST_AddMeasure¶
Introduction: Computes a new geometry with measure (M) values linearly interpolated between start and end points. For geometries lacking M dimensions, M values are added. Existing M values are overwritten by the new values. Applies only to LineString and MultiLineString inputs.
Format: ST_AddMeasure(geom: Geometry, measureStart: Double, measureEnd: Double)
Since: v1.6.1
SQL Example:
SELECT ST_AsText(ST_AddMeasure(
ST_GeomFromWKT('LINESTRING (0 0, 1 0, 2 0, 3 0, 4 0, 5 0)')
))
Output:
LINESTRING M(0 0 10, 1 0 16, 2 0 22, 3 0 28, 4 0 34, 5 0 40)
ST_AddPoint¶
Introduction: Return Linestring with additional point at the given index, if position is not available the point will be added at the end of line.
Format:
ST_AddPoint(geom: Geometry, point: Geometry, position: Integer)
ST_AddPoint(geom: Geometry, point: Geometry)
Since: v1.3.0
Example:
SELECT ST_AddPoint(ST_GeomFromText("LINESTRING(0 0, 1 1, 1 0)"), ST_GeomFromText("Point(21 52)"), 1)
SELECT ST_AddPoint(ST_GeomFromText("Linestring(0 0, 1 1, 1 0)"), ST_GeomFromText("Point(21 52)"))
Output:
LINESTRING(0 0, 21 52, 1 1, 1 0)
LINESTRING(0 0, 1 1, 1 0, 21 52)
ST_Affine¶
Introduction: Apply an affine transformation to the given geometry.
ST_Affine has 2 overloaded signatures:
ST_Affine(geometry, a, b, c, d, e, f, g, h, i, xOff, yOff, zOff)
ST_Affine(geometry, a, b, d, e, xOff, yOff)
Based on the invoked function, the following transformation is applied:
x = a * x + b * y + c * z + xOff OR x = a * x + b * y + xOff
y = d * x + e * y + f * z + yOff OR y = d * x + e * y + yOff
z = g * x + f * y + i * z + zOff OR z = g * x + f * y + zOff
If the given geometry is empty, the result is also empty.
Format:
ST_Affine(geometry, a, b, c, d, e, f, g, h, i, xOff, yOff, zOff)
ST_Affine(geometry, a, b, d, e, xOff, yOff)
Since: v1.5.0
Examples:
ST_Affine(geometry, 1, 2, 4, 1, 1, 2, 3, 2, 5, 4, 8, 3)
Input: LINESTRING EMPTY
Output: LINESTRING EMPTY
Input: POLYGON ((1 0 1, 1 1 1, 2 2 2, 1 0 1))
Output: POLYGON Z((9 11 11, 11 12 13, 18 16 23, 9 11 11))
Input: POLYGON ((1 0, 1 1, 2 1, 2 0, 1 0), (1 0.5, 1 0.75, 1.5 0.75, 1.5 0.5, 1 0.5))
Output: POLYGON((5 9, 7 10, 8 11, 6 10, 5 9), (6 9.5, 6.5 9.75, 7 10.25, 6.5 10, 6 9.5))
ST_Affine(geometry, 1, 2, 1, 2, 1, 2)
Input: POLYGON EMPTY
Output: POLYGON EMPTY
Input: GEOMETRYCOLLECTION (MULTIPOLYGON (((1 0, 1 1, 2 1, 2 0, 1 0), (1 0.5, 1 0.75, 1.5 0.75, 1.5 0.5, 1 0.5)), ((5 0, 5 5, 7 5, 7 0, 5 0))), POINT (10 10))
Output: GEOMETRYCOLLECTION (MULTIPOLYGON (((2 3, 4 5, 5 6, 3 4, 2 3), (3 4, 3.5 4.5, 4 5, 3.5 4.5, 3 4)), ((6 7, 16 17, 18 19, 8 9, 6 7))), POINT (31 32))
Input: POLYGON ((1 0 1, 1 1 1, 2 2 2, 1 0 1))
Output: POLYGON Z((2 3 1, 4 5 1, 7 8 2, 2 3 1))
ST_Angle¶
Introduction: Compute and return the angle between two vectors represented by the provided points or linestrings.
There are three variants possible for ST_Angle:
ST_Angle(point1: Geometry, point2: Geometry, point3: Geometry, point4: Geometry)
Computes the angle formed by vectors represented by point1 - point2 and point3 - point4
ST_Angle(point1: Geometry, point2: Geometry, point3: Geometry)
Computes the angle formed by vectors represented by point2 - point1 and point2 - point3
ST_Angle(line1: Geometry, line2: Geometry)
Computes the angle formed by vectors S1 - E1 and S2 - E2, where S and E denote start and end points respectively
Note
If any other geometry type is provided, ST_Angle throws an IllegalArgumentException. Additionally, if any of the provided geometry is empty, ST_Angle throws an IllegalArgumentException.
Note
If a 3D geometry is provided, ST_Angle computes the angle ignoring the z ordinate, equivalent to calling ST_Angle for corresponding 2D geometries.
Tip
ST_Angle returns the angle in radian between 0 and 2\Pi. To convert the angle to degrees, use ST_Degrees.
Format: ST_Angle(p1, p2, p3, p4) | ST_Angle(p1, p2, p3) | ST_Angle(line1, line2)
Since: v1.5.0
Example:
SELECT ST_Angle(ST_GeomFromWKT('POINT(0 0)'), ST_GeomFromWKT('POINT (1 1)'), ST_GeomFromWKT('POINT(1 0)'), ST_GeomFromWKT('POINT(6 2)'))
Output:
0.4048917862850834
Example:
SELECT ST_Angle(ST_GeomFromWKT('POINT (1 1)'), ST_GeomFromWKT('POINT (0 0)'), ST_GeomFromWKT('POINT(3 2)'))
Output:
0.19739555984988044
Example:
SELECT ST_Angle(ST_GeomFromWKT('LINESTRING (0 0, 1 1)'), ST_GeomFromWKT('LINESTRING (0 0, 3 2)'))
Output:
0.19739555984988044
ST_Area¶
Introduction: Return the area of A
Format: ST_Area (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_Area(ST_GeomFromText("POLYGON(0 0, 0 10, 10 10, 0 10, 0 0)"))
Output:
10
ST_AreaSpheroid¶
Introduction: Return the geodesic area of A using WGS84 spheroid. Unit is meter. Works better for large geometries (country level) compared to ST_Area + ST_Transform. It is equivalent to PostGIS ST_Area(geography, use_spheroid=true) function and produces nearly identical results.
Geometry must be in EPSG:4326 (WGS84) projection and must be in lon/lat order. You can use ST_FlipCoordinates to swap lat and lon.
Note
By default, this function uses lon/lat order since v1.5.0. Before, it used lat/lon order.
Format: ST_AreaSpheroid (A: Geometry)
Since: v1.4.1
Example:
SELECT ST_AreaSpheroid(ST_GeomFromWKT('Polygon ((34 35, 28 30, 25 34, 34 35))'))
Output:
201824850811.76245
ST_AsBinary¶
Introduction: Return the Well-Known Binary representation of a geometry
Format: ST_AsBinary (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsBinary(ST_GeomFromWKT('POINT (1 1)'))
Output:
0101000000000000000000f87f000000000000f87f
ST_AsEWKB¶
Introduction: Return the Extended Well-Known Binary representation of a geometry. EWKB is an extended version of WKB which includes the SRID of the geometry. The format originated in PostGIS but is supported by many GIS tools. If the geometry is lacking SRID a WKB format is produced. It will ignore the M coordinate if present.
Format: ST_AsEWKB (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsEWKB(ST_SetSrid(ST_GeomFromWKT('POINT (1 1)'), 3021))
Output:
0101000020cd0b0000000000000000f03f000000000000f03f
ST_AsEWKT¶
Introduction: Return the Extended Well-Known Text representation of a geometry. EWKT is an extended version of WKT which includes the SRID of the geometry. The format originated in PostGIS but is supported by many GIS tools. If the geometry is lacking SRID a WKT format is produced. See ST_SetSRID It will support M coordinate if present since v1.5.0.
Format: ST_AsEWKT (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_AsEWKT(ST_SetSrid(ST_GeomFromWKT('POLYGON((0 0,0 1,1 1,1 0,0 0))'), 4326))
Output:
SRID=4326;POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))
Example:
SELECT ST_AsEWKT(ST_MakePointM(1.0, 1.0, 1.0))
Output:
POINT M(1 1 1)
Example:
SELECT ST_AsEWKT(ST_MakePoint(1.0, 1.0, 1.0, 1.0))
Output:
POINT ZM(1 1 1 1)
ST_AsGeoJSON¶
Introduction: Return the GeoJSON string representation of a geometry.
The type parameter (Since: v1.6.1) takes the following options -
- "Simple" (default): Returns a simple GeoJSON geometry.
- "Feature": Wraps the geometry in a GeoJSON Feature.
- "FeatureCollection": Wraps the Feature in a GeoJSON FeatureCollection.
Format:
ST_AsGeoJSON (A: Geometry)
ST_AsGeoJSON (A: Geometry, type: String)
Since: v1.3.0
SQL Example (Simple GeoJSON):
SELECT ST_AsGeoJSON(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'))
Output:
{
"type":"Polygon",
"coordinates":[
[[1.0,1.0],
[8.0,1.0],
[8.0,8.0],
[1.0,8.0],
[1.0,1.0]]
]
}
SQL Example (Feature GeoJSON):
Output:
{
"type":"Feature",
"geometry": {
"type":"Polygon",
"coordinates":[
[[1.0,1.0],
[8.0,1.0],
[8.0,8.0],
[1.0,8.0],
[1.0,1.0]]
]
}
}
SQL Example (FeatureCollection GeoJSON):
Output:
{
"type":"FeatureCollection",
"features": [{
"type":"Feature",
"geometry": {
"type":"Polygon",
"coordinates":[
[[1.0,1.0],
[8.0,1.0],
[8.0,8.0],
[1.0,8.0],
[1.0,1.0]]
]
}
}
]
}
ST_AsGML¶
Introduction: Return the GML string representation of a geometry
Format: ST_AsGML (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsGML(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'))
Output:
1.0,1.0 8.0,1.0 8.0,8.0 1.0,8.0 1.0,1.0
ST_AsHEXEWKB¶
Introduction: This function returns the input geometry encoded to a text representation in HEXEWKB format. The HEXEWKB encoding can use either little-endian (NDR) or big-endian (XDR) byte ordering. If no encoding is explicitly specified, the function defaults to using the little-endian (NDR) format.
Format: ST_AsHEXEWKB(geom: Geometry, endian: String = NDR)
Since: v1.6.1
SQL Example
SELECT ST_AsHEXEWKB(ST_GeomFromWKT('POINT(1 2)'), 'XDR')
Output:
00000000013FF00000000000004000000000000000
SQL Example
SELECT ST_AsHEXEWKB(ST_GeomFromWKT('LINESTRING (30 20, 20 25, 20 15, 30 20)'))
Output:
0102000000040000000000000000003E4000000000000034400000000000003440000000000000394000000000000034400000000000002E400000000000003E400000000000003440
ST_AsKML¶
Introduction: Return the KML string representation of a geometry
Format: ST_AsKML (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsKML(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'))
Output:
1.0,1.0 8.0,1.0 8.0,8.0 1.0,8.0 1.0,1.0
ST_AsText¶
Introduction: Return the Well-Known Text string representation of a geometry. It will support M coordinate if present since v1.5.0.
Format: ST_AsText (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsText(ST_SetSRID(ST_Point(1.0,1.0), 3021))
Output:
POINT (1 1)
Example:
SELECT ST_AsText(ST_MakePointM(1.0, 1.0, 1.0))
Output:
POINT M(1 1 1)
Example:
SELECT ST_AsText(ST_MakePoint(1.0, 1.0, 1.0, 1.0))
Output:
POINT ZM(1 1 1 1)
ST_Azimuth¶
Introduction: Returns Azimuth for two given points in radians null otherwise.
Format: ST_Azimuth(pointA: Point, pointB: Point)
Since: v1.3.0
Example:
SELECT ST_Azimuth(ST_POINT(0.0, 25.0), ST_POINT(0.0, 0.0))
Output:
3.141592653589793
ST_BestSRID¶
Introduction: Returns the estimated most appropriate Spatial Reference Identifier (SRID) for a given geometry, based on its spatial extent and location. It evaluates the geometry's bounding envelope and selects an SRID that optimally represents the geometry on the Earth's surface. The function prioritizes Universal Transverse Mercator (UTM), Lambert Azimuthal Equal Area (LAEA), or falls back to the Mercator projection. The function takes a WGS84 geometry and must be in lon/lat order.
- For geometries in the Arctic or Antarctic regions, the Lambert Azimuthal Equal Area projection is used.
- For geometries that fit within a single UTM zone and do not cross the International Date Line (IDL), a corresponding UTM SRID is chosen.
- In cases where none of the above conditions are met, the function defaults to the Mercator projection.
- For Geometries that cross the IDL,
ST_BestSRIDdefaults the SRID to Mercator. Currently,ST_BestSRIDdoes not handle geometries crossing the IDL.
Warning
ST_BestSRID is designed to estimate a suitable SRID from a set of approximately 125 EPSG codes and works best for geometries that fit within the UTM zones. It should not be solely relied upon to determine the most accurate SRID, especially for specialized or high-precision spatial requirements.
Format: ST_BestSRID(geom: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_BestSRID(ST_GeomFromWKT('POLYGON((-73.9980 40.7265, -73.9970 40.7265, -73.9970 40.7255, -73.9980 40.7255, -73.9980 40.7265))'))
Output:
32618
ST_Boundary¶
Introduction: Returns the closure of the combinatorial boundary of this Geometry.
Format: ST_Boundary(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_Boundary(ST_GeomFromText('POLYGON ((1 1, 0 0, -1 1, 1 1))'))
Output:
LINEARRING (1 1, 0 0, -1 1, 1 1)
ST_BoundingDiagonal¶
Introduction: Returns a linestring spanning minimum and maximum values of each dimension of the given geometry's coordinates as its start and end point respectively. If an empty geometry is provided, the returned LineString is also empty. If a single vertex (POINT) is provided, the returned LineString has both the start and end points same as the points coordinates
Format: ST_BoundingDiagonal(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_BoundingDiagonal(ST_GeomFromWKT(geom))
Input: POLYGON ((1 1 1, 3 3 3, 0 1 4, 4 4 0, 1 1 1))
Output: LINESTRING Z(0 1 1, 4 4 4)
Input: POINT (10 10)
Output: LINESTRING (10 10, 10 10)
Input: GEOMETRYCOLLECTION(POLYGON ((5 5 5, -1 2 3, -1 -1 0, 5 5 5)), POINT (10 3 3))
Output: LINESTRING Z(-1 -1 0, 10 5 5)
ST_Buffer¶
Introduction: Returns a geometry/geography that represents all points whose distance from this Geometry/geography is less than or equal to distance. The function supports both Planar/Euclidean and Spheroidal/Geodesic buffering (Since v1.6.0). Spheroidal buffer also supports geometries crossing the International Date Line (IDL).
Mode of buffer calculation (Since: v1.6.0):
The optional third parameter, useSpheroid, controls the mode of buffer calculation.
- Planar Buffering (default): When
useSpheroidis false,ST_Bufferperforms standard planar buffering based on the provided parameters. - Spheroidal Buffering:
- When
useSpheroidis set to true, the function returns the spheroidal buffer polygon for more accurate representation over the Earth. In this mode, the unit of the buffer distance is interpreted as meters. - ST_Buffer first determines the most appropriate Spatial Reference Identifier (SRID) for a given geometry, based on its spatial extent and location, using
ST_BestSRID. - The geometry is then transformed from its original SRID to the selected SRID. If the input geometry does not have a set SRID,
ST_Bufferdefaults to using WGS 84 (SRID 4326) as its original SRID. - The standard planar buffer operation is then applied in this coordinate system.
- Finally, the buffered geometry is transformed back to its original SRID, or to WGS 84 if the original SRID was not set.
- When
Note
Spheroidal buffering only supports lon/lat coordinate systems and will throw an IllegalArgumentException for input geometries in meter based coordinate systems.
Note
Spheroidal buffering may not produce accurate output buffer for input geometries larger than a UTM zone.
Buffer Style Parameters:
The optional forth parameter controls the buffer accuracy and style. Buffer accuracy is specified by the number of line segments approximating a quarter circle, with a default of 8 segments. Buffer style can be set by providing blank-separated key=value pairs in a list format.
quad_segs=#: Number of line segments utilized to approximate a quarter circle (default is 8).endcap=round|flat|square: End cap style (default isround).buttis an accepted synonym forflat.join=round|mitre|bevel: Join style (default isround).miteris an accepted synonym formitre.mitre_limit=#.#: mitre ratio limit and it only affects mitred join style.miter_limitis an accepted synonym formitre_limit.side=both|left|right: The optionleftorrightenables a single-sided buffer operation on the geometry, with the buffered side aligned according to the direction of the line. This functionality is specific to LINESTRING geometry and has no impact on POINT or POLYGON geometries. By default, square end caps are applied.
Note
ST_Buffer throws an IllegalArgumentException if the correct format, parameters, or options are not provided.
Format:
ST_Buffer (A: Geometry, buffer: Double)
ST_Buffer (A: Geometry, buffer: Double, useSpheroid: Boolean)
ST_Buffer (A: Geometry, buffer: Double, useSpheroid: Boolean, bufferStyleParameters: String)
Since: v1.5.1
SQL Example:
SELECT ST_Buffer(ST_GeomFromWKT('POINT(0 0)'), 10)
SELECT ST_Buffer(ST_GeomFromWKT('POINT(0 0)'), 10, false, 'quad_segs=2')
Output:
8 Segments 2 Segments
SQL Example:
SELECT ST_Buffer(ST_GeomFromWKT('LINESTRING(0 0, 50 70, 100 100)'), 10, false, 'side=left')
Output:
Original Linestring Left side buffed Linestring
ST_BuildArea¶
Introduction: Returns the areal geometry formed by the constituent linework of the input geometry.
Format: ST_BuildArea (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_BuildArea(ST_Collect(smallDf, bigDf)) AS geom
FROM smallDf, bigDf
Input: MULTILINESTRING((0 0, 10 0, 10 10, 0 10, 0 0),(10 10, 20 10, 20 20, 10 20, 10 10))
Output: MULTIPOLYGON(((0 0,0 10,10 10,10 0,0 0)),((10 10,10 20,20 20,20 10,10 10)))
ST_Centroid¶
Introduction: Return the centroid point of A
Format: ST_Centroid (A: Geometry)
Since: v1.5.0
Example:
SELECT ST_Centroid(ST_GeomFromWKT('MULTIPOINT(-1 0, -1 2, 7 8, 9 8, 10 6)'))
Output:
POINT (4.8 4.8)
ST_ClosestPoint¶
Introduction: Returns the 2-dimensional point on geom1 that is closest to geom2. This is the first point of the shortest line between the geometries. If using 3D geometries, the Z coordinates will be ignored. If you have a 3D Geometry, you may prefer to use ST_3DClosestPoint. It will throw an exception indicates illegal argument if one of the params is an empty geometry.
Format: ST_ClosestPoint(g1: Geometry, g2: Geometry)
Since: v1.5.0
Example:
SELECT ST_AsText( ST_ClosestPoint(g1, g2)) As ptwkt;
Input: g1: POINT (160 40), g2: LINESTRING (10 30, 50 50, 30 110, 70 90, 180 140, 130 190)
Output: POINT(160 40)
Input: g1: LINESTRING (10 30, 50 50, 30 110, 70 90, 180 140, 130 190), g2: POINT (160 40)
Output: POINT(125.75342465753425 115.34246575342466)
Input: g1: 'POLYGON ((190 150, 20 10, 160 70, 190 150))', g2: ST_Buffer('POINT(80 160)', 30)
Output: POINT(131.59149149528952 101.89887534906197)
ST_Collect¶
Introduction: Returns MultiGeometry object based on geometry column/s or array with geometries
Format:
ST_Collect(*geom: Geometry)
ST_Collect(geom: ARRAY[Geometry])
Since: v1.5.0
Example:
SELECT ST_Collect(
ST_GeomFromText('POINT(21.427834 52.042576573)'),
ST_GeomFromText('POINT(45.342524 56.342354355)')
) AS geom
Result:
+---------------------------------------------------------------+
|geom |
+---------------------------------------------------------------+
|MULTIPOINT ((21.427834 52.042576573), (45.342524 56.342354355))|
+---------------------------------------------------------------+
Example:
SELECT ST_Collect(
Array(
ST_GeomFromText('POINT(21.427834 52.042576573)'),
ST_GeomFromText('POINT(45.342524 56.342354355)')
)
) AS geom
Result:
+---------------------------------------------------------------+
|geom |
+---------------------------------------------------------------+
|MULTIPOINT ((21.427834 52.042576573), (45.342524 56.342354355))|
+---------------------------------------------------------------+
ST_CollectionExtract¶
Introduction: Returns a homogeneous multi-geometry from a given geometry collection.
The type numbers are:
- POINT
- LINESTRING
- POLYGON
If the type parameter is omitted a multi-geometry of the highest dimension is returned.
Format:
ST_CollectionExtract (A: Geometry)
ST_CollectionExtract (A: Geometry, type: Integer)
Since: v1.5.0
Example:
WITH test_data as (
ST_GeomFromText(
'GEOMETRYCOLLECTION(POINT(40 10), POLYGON((0 0, 0 5, 5 5, 5 0, 0 0)))'
) as geom
)
SELECT ST_CollectionExtract(geom) as c1, ST_CollectionExtract(geom, 1) as c2
FROM test_data
Result:
+----------------------------------------------------------------------------+
|c1 |c2 |
+----------------------------------------------------------------------------+
|MULTIPOLYGON(((0 0, 0 5, 5 5, 5 0, 0 0))) |MULTIPOINT(40 10) | |
+----------------------------------------------------------------------------+
ST_ConcaveHull¶
Introduction: Return the Concave Hull of polygon A, with alpha set to pctConvex[0, 1] in the Delaunay Triangulation method, the concave hull will not contain a hole unless allowHoles is set to true
Format:
ST_ConcaveHull (A: Geometry, pctConvex: Double)
ST_ConcaveHull (A: Geometry, pctConvex: Double, allowHoles: Boolean)
Since: v1.4.0
Example:
SELECT ST_ConcaveHull(ST_GeomFromWKT('POLYGON((175 150, 20 40, 50 60, 125 100, 175 150))'), 1)
Output:
POLYGON ((125 100, 20 40, 50 60, 175 150, 125 100))
ST_ConvexHull¶
Introduction: Return the Convex Hull of polygon A
Format: ST_ConvexHull (A: Geometry)
Since: v1.5.0
Example:
SELECT ST_ConvexHull(ST_GeomFromText('POLYGON((175 150, 20 40, 50 60, 125 100, 175 150))'))
Output:
POLYGON ((20 40, 175 150, 125 100, 20 40))
ST_CoordDim¶
Introduction: Returns the coordinate dimensions of the geometry. It is an alias of ST_NDims.
Format: ST_CoordDim(geom: Geometry)
Since: v1.5.0
Example with x, y, z coordinate:
SELECT ST_CoordDim(ST_GeomFromText('POINT(1 1 2'))
Output:
3
Example with x, y coordinate:
SELECT ST_CoordDim(ST_GeomFromWKT('POINT(3 7)'))
Output:
2
ST_CrossesDateLine¶
Introduction: This function determines if a given geometry crosses the International Date Line. It operates by checking if the difference in longitude between any pair of consecutive points in the geometry exceeds 180 degrees. If such a difference is found, it is assumed that the geometry crosses the Date Line. It returns true if the geometry crosses the Date Line, and false otherwise.
Note
The function assumes that the provided geometry is in lon/lat coordinate reference system where longitude values range from -180 to 180 degrees.
Note
For multi-geometries (e.g., MultiPolygon, MultiLineString), this function will return true if any one of the geometries within the multi-geometry crosses the International Date Line.
Format: ST_CrossesDateLine(geometry: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_CrossesDateLine(ST_GeomFromWKT('LINESTRING(170 30, -170 30)'))
Output:
true
Warning
For geometries that span more than 180 degrees in longitude without actually crossing the Date Line, this function may still return true, indicating a crossing.
ST_Dimension¶
Introduction: Return the topological dimension of this Geometry object, which must be less than or equal to the coordinate dimension. OGC SPEC s2.1.1.1 - returns 0 for POINT, 1 for LINESTRING, 2 for POLYGON, and the largest dimension of the components of a GEOMETRYCOLLECTION. If the dimension is unknown (e.g. for an empty GEOMETRYCOLLECTION) 0 is returned.
Format: ST_Dimension (A: Geometry) | ST_Dimension (C: Geometrycollection)
Since: v1.5.0
Example:
SELECT ST_Dimension('GEOMETRYCOLLECTION(LINESTRING(1 1,0 0),POINT(0 0))');
Result:
1
ST_Distance¶
Introduction: Return the Euclidean distance between A and B
Format: ST_Distance (A: Geometry, B: Geometry)
Since: v1.2.0
Example:
SELECT ST_Distance(ST_GeomFromText('POINT(72 42)'), ST_GeomFromText('LINESTRING(-72 -42, 82 92)'))
Output:
31.155515639003543
ST_DistanceSphere¶
Introduction: Return the haversine / great-circle distance of A using a given earth radius (default radius: 6371008.0). Unit is meter. Works better for large geometries (country level) compared to ST_Distance + ST_Transform. It is equivalent to PostGIS ST_Distance(geography, use_spheroid=false) and ST_DistanceSphere function and produces nearly identical results. It provides faster but less accurate result compared to ST_DistanceSpheroid.
Geometry must be in EPSG:4326 (WGS84) projection and must be in lon/lat order. You can use ST_FlipCoordinates to swap lat and lon. For non-point data, we first take the centroids of both geometries and then compute the distance.
Note
By default, this function uses lon/lat order since v1.5.0. Before, it used lat/lon order.
Format: ST_DistanceSphere (A: Geometry)
Since: v1.4.1
Example 1:
SELECT ST_DistanceSphere(ST_GeomFromWKT('POINT (-0.56 51.3168)'), ST_GeomFromWKT('POINT (-3.1883 55.9533)'))
Output:
543796.9506134904
Example 2:
SELECT ST_DistanceSphere(ST_GeomFromWKT('POINT (-0.56 51.3168)'), ST_GeomFromWKT('POINT (-3.1883 55.9533)'), 6378137.0)
Output:
544405.4459192449
ST_DistanceSpheroid¶
Introduction: Return the geodesic distance of A using WGS84 spheroid. Unit is meter. Works better for large geometries (country level) compared to ST_Distance + ST_Transform. It is equivalent to PostGIS ST_Distance(geography, use_spheroid=true) and ST_DistanceSpheroid function and produces nearly identical results. It provides slower but more accurate result compared to ST_DistanceSphere.
Geometry must be in EPSG:4326 (WGS84) projection and must be in lon/lat order. You can use ST_FlipCoordinates to swap lat and lon. For non-point data, we first take the centroids of both geometries and then compute the distance.
Note
By default, this function uses lon/lat order since v1.5.0. Before, it used lat/lon order.
Format: ST_DistanceSpheroid (A: Geometry)
Since: v1.4.1
Example:
SELECT ST_DistanceSpheroid(ST_GeomFromWKT('POINT (-0.56 51.3168)'), ST_GeomFromWKT('POINT (-3.1883 55.9533)'))
Output:
544430.9411996207
ST_Degrees¶
Introduction: Convert an angle in radian to degrees.
Format: ST_Degrees(angleInRadian)
Since: v1.5.0
Example:
SELECT ST_Degrees(0.19739555984988044)
Output:
11.309932474020195
ST_DelaunayTriangles¶
Introduction: This function computes the Delaunay triangulation for the set of vertices in the input geometry. An optional tolerance parameter allows snapping nearby input vertices together prior to triangulation and can improve robustness in certain scenarios by handling near-coincident vertices. The default for tolerance is 0. The Delaunay triangulation geometry is bounded by the convex hull of the input vertex set.
The output geometry representation depends on the provided flag:
0- a GeometryCollection of triangular Polygons (default option)1- a MultiLinestring of the edges of the triangulation
Format:
ST_DelaunayTriangles(geometry: Geometry)
ST_DelaunayTriangles(geometry: Geometry, tolerance: Double)
ST_DelaunayTriangles(geometry: Geometry, tolerance: Double, flag: Integer)
Since: v1.6.1
SQL Example
SELECT ST_DelaunayTriangles(
ST_GeomFromWKT('POLYGON ((10 10, 15 30, 20 25, 25 35, 30 20, 40 30, 50 10, 45 5, 35 15, 30 5, 25 15, 20 10, 15 20, 10 10))')
)
Output:
GEOMETRYCOLLECTION (POLYGON ((15 30, 10 10, 15 20, 15 30)), POLYGON ((15 30, 15 20, 20 25, 15 30)), POLYGON ((15 30, 20 25, 25 35, 15 30)), POLYGON ((25 35, 20 25, 30 20, 25 35)), POLYGON ((25 35, 30 20, 40 30, 25 35)), POLYGON ((40 30, 30 20, 35 15, 40 30)), POLYGON ((40 30, 35 15, 50 10, 40 30)), POLYGON ((50 10, 35 15, 45 5, 50 10)), POLYGON ((30 5, 45 5, 35 15, 30 5)), POLYGON ((30 5, 35 15, 25 15, 30 5)), POLYGON ((30 5, 25 15, 20 10, 30 5)), POLYGON ((30 5, 20 10, 10 10, 30 5)), POLYGON ((10 10, 20 10, 15 20, 10 10)), POLYGON ((15 20, 20 10, 25 15, 15 20)), POLYGON ((15 20, 25 15, 20 25, 15 20)), POLYGON ((20 25, 25 15, 30 20, 20 25)), POLYGON ((30 20, 25 15, 35 15, 30 20)))
ST_Difference¶
Introduction: Return the difference between geometry A and B (return part of geometry A that does not intersect geometry B)
Format: ST_Difference (A: Geometry, B: Geometry)
Since: v1.5.0
Example:
SELECT ST_Difference(ST_GeomFromWKT('POLYGON ((-3 -3, 3 -3, 3 3, -3 3, -3 -3))'), ST_GeomFromWKT('POLYGON ((0 -4, 4 -4, 4 4, 0 4, 0 -4))'))
Result:
POLYGON ((0 -3, -3 -3, -3 3, 0 3, 0 -3))
ST_Dump¶
Introduction: It expands the geometries. If the geometry is simple (Point, Polygon Linestring etc.) it returns the geometry itself, if the geometry is collection or multi it returns record for each of collection components.
Format: ST_Dump(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_Dump(ST_GeomFromText('MULTIPOINT ((10 40), (40 30), (20 20), (30 10))'))
Output:
[POINT (10 40), POINT (40 30), POINT (20 20), POINT (30 10)]
ST_DumpPoints¶
Introduction: Returns list of Points which geometry consists of.
Format: ST_DumpPoints(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_DumpPoints(ST_GeomFromText('LINESTRING (0 0, 1 1, 1 0)'))
Output:
[POINT (0 0), POINT (0 1), POINT (1 1), POINT (1 0), POINT (0 0)]
ST_EndPoint¶
Introduction: Returns last point of given linestring.
Format: ST_EndPoint(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_EndPoint(ST_GeomFromText('LINESTRING(100 150,50 60, 70 80, 160 170)'))
Output:
POINT(160 170)
ST_Envelope¶
Introduction: Return the envelope boundary of A
Format: ST_Envelope (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_Envelope(ST_GeomFromWKT('LINESTRING(0 0, 1 3)'))
Output:
POLYGON ((0 0, 0 3, 1 3, 1 0, 0 0))
ST_Expand¶
Introduction: Returns a geometry expanded from the bounding box of the input. The expansion can be specified in two ways:
- By individual axis using
deltaX,deltaY, ordeltaZparameters. - Uniformly across all axes using the
uniformDeltaparameter.
Note
Things to consider when using this function:
- The
uniformDeltaparameter expands Z dimensions for XYZ geometries; otherwise, it only affects XY dimensions. - For XYZ geometries, specifying only
deltaXanddeltaYwill preserve the original Z dimension. - If the input geometry has an M dimension then using this function will drop the said M dimension.
Format:
ST_Expand(geometry: Geometry, uniformDelta: Double)
ST_Expand(geometry: Geometry, deltaX: Double, deltaY: Double)
ST_Expand(geometry: Geometry, deltaX: Double, deltaY: Double, deltaZ: Double)
Since: v1.6.1
SQL Example:
SELECT ST_Expand(
ST_GeomFromWKT('POLYGON Z((50 50 1, 50 80 2, 80 80 3, 80 50 2, 50 50 1))'),
10
)
Output:
POLYGON Z((40 40 -9, 40 90 -9, 90 90 13, 90 40 13, 40 40 -9))
ST_ExteriorRing¶
Introduction: Returns a LINESTRING representing the exterior ring (shell) of a POLYGON. Returns NULL if the geometry is not a polygon.
Format: ST_ExteriorRing(A: Geometry)
Since: v1.2.1
Example:
SELECT ST_ExteriorRing(ST_GeomFromText('POLYGON((0 0 1, 1 1 1, 1 2 1, 1 1 1, 0 0 1))'))
Output:
LINESTRING (0 0, 1 1, 1 2, 1 1, 0 0)
ST_FlipCoordinates¶
Introduction: Returns a version of the given geometry with X and Y axis flipped.
Format: ST_FlipCoordinates(A: Geometry)
Since: v1.2.0
Example:
SELECT ST_FlipCoordinates(ST_GeomFromWKT("POINT (1 2)"))
Output:
POINT (2 1)
ST_Force_2D¶
Introduction: Forces the geometries into a "2-dimensional mode" so that all output representations will only have the X and Y coordinates
Format: ST_Force_2D (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_Force_2D(ST_GeomFromText('POLYGON((0 0 2,0 5 2,5 0 2,0 0 2),(1 1 2,3 1 2,1 3 2,1 1 2))'))
Output:
POLYGON((0 0,0 5,5 0,0 0),(1 1,3 1,1 3,1 1))
ST_Force3D¶
Introduction: Forces the geometry into a 3-dimensional model so that all output representations will have X, Y and Z coordinates. An optionally given zValue is tacked onto the geometry if the geometry is 2-dimensional. Default value of zValue is 0.0 If the given geometry is 3-dimensional, no change is performed on it. If the given geometry is empty, no change is performed on it.
Note
Example output is after calling ST_AsText() on returned geometry, which adds Z for in the WKT for 3D geometries
Format: ST_Force3D(geometry: Geometry, zValue: Double)
Since: v1.4.1
Example:
SELECT ST_AsText(ST_Force3D(ST_GeomFromText('POLYGON((0 0 2,0 5 2,5 0 2,0 0 2),(1 1 2,3 1 2,1 3 2,1 1 2))'), 2.3))
Output:
POLYGON Z((0 0 2, 0 5 2, 5 0 2, 0 0 2), (1 1 2, 3 1 2, 1 3 2, 1 1 2))
Example:
SELECT ST_AsText(ST_Force3D(ST_GeomFromText('LINESTRING(0 1,1 0,2 0)'), 2.3))
Output:
LINESTRING Z(0 1 2.3, 1 0 2.3, 2 0 2.3)
Example:
SELECT ST_AsText(ST_Force3D(ST_GeomFromText('LINESTRING EMPTY'), 3))
Output:
LINESTRING EMPTY
ST_Force3DM¶
Introduction: Forces the geometry into XYM mode. Retains any existing M coordinate, but removes the Z coordinate if present. Assigns a default M value of 0.0 if mValue is not specified.
Note
Example output is after calling ST_AsText() on returned geometry, which adds M for in the WKT.
Format: ST_Force3DM(geometry: Geometry, mValue: Double = 0.0)
Since: v1.6.1
SQL Example
SELECT ST_AsText(ST_Force3DM(ST_GeomFromText('POLYGON M((0 0 3,0 5 3,5 0 3,0 0 3),(1 1 3,3 1 3,1 3 3,1 1 3))'), 2.3))
Output:
POLYGON M((0 0 3, 0 5 3, 5 0 3, 0 0 3), (1 1 3, 3 1 3, 1 3 3, 1 1 3))
SQL Example
SELECT ST_AsText(ST_Force3DM(ST_GeomFromText('LINESTRING(0 1,1 0,2 0)'), 2.3))
Output:
LINESTRING M(0 1 2.3, 1 0 2.3, 2 0 2.3)
SQL Example
SELECT ST_AsText(ST_Force3DM(ST_GeomFromText('LINESTRING Z(0 1 3,1 0 3,2 0 3)'), 5))
Output:
LINESTRING M(0 1 5, 1 0 5, 2 0 5)
ST_Force3DZ¶
Introduction: Forces the geometry into a 3-dimensional model so that all output representations will have X, Y and Z coordinates. An optionally given zValue is tacked onto the geometry if the geometry is 2-dimensional. Default value of zValue is 0.0 If the given geometry is 3-dimensional, no change is performed on it. If the given geometry is empty, no change is performed on it. This function is an alias for ST_Force3D.
Note
Example output is after calling ST_AsText() on returned geometry, which adds Z for in the WKT for 3D geometries
Format: ST_Force3DZ(geometry: Geometry, zValue: Double)
Since: v1.6.1
SQL Example
SELECT ST_AsText(ST_Force3DZ(ST_GeomFromText('POLYGON((0 0 2,0 5 2,5 0 2,0 0 2),(1 1 2,3 1 2,1 3 2,1 1 2))'), 2.3))
Output:
POLYGON Z((0 0 2, 0 5 2, 5 0 2, 0 0 2), (1 1 2, 3 1 2, 1 3 2, 1 1 2))
SQL Example
SELECT ST_AsText(ST_Force3DZ(ST_GeomFromText('LINESTRING(0 1,1 0,2 0)'), 2.3))
Output:
LINESTRING Z(0 1 2.3, 1 0 2.3, 2 0 2.3)
ST_Force4D¶
Introduction: Converts the input geometry to 4D XYZM representation. Retains original Z and M values if present. Assigning 0.0 defaults if mValue and zValue aren't specified. The output contains X, Y, Z, and M coordinates. For geometries already in 4D form, the function returns the original geometry unmodified.
Note
Example output is after calling ST_AsText() on returned geometry, which adds Z for in the WKT for 3D geometries
Format:
ST_Force4D(geom: Geometry, zValue: Double, mValue: Double)
ST_Force4D(geom: Geometry
Since: v1.6.1
SQL Example
SELECT ST_AsText(ST_Force4D(ST_GeomFromText('POLYGON((0 0 2,0 5 2,5 0 2,0 0 2),(1 1 2,3 1 2,1 3 2,1 1 2))'), 5, 10))
Output:
POLYGON ZM((0 0 2 10, 0 5 2 10, 5 0 2 10, 0 0 2 10), (1 1 2 10, 3 1 2 10, 1 3 2 10, 1 1 2 10))
SQL Example
SELECT ST_AsText(ST_Force4D(ST_GeomFromText('LINESTRING(0 1,1 0,2 0)'), 3, 1))
Output:
LINESTRING ZM(0 1 3 1, 1 0 3 1, 2 0 3 1)
ST_ForceCollection¶
Introduction: This function converts the input geometry into a GeometryCollection, regardless of the original geometry type. If the input is a multipart geometry, such as a MultiPolygon or MultiLineString, it will be decomposed into a GeometryCollection containing each individual Polygon or LineString element from the original multipart geometry.
Format: ST_ForceCollection(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_ForceCollection(
ST_GeomFromWKT(
"MULTIPOINT (30 10, 40 40, 20 20, 10 30, 10 10, 20 50)"
)
)
Output:
GEOMETRYCOLLECTION (POINT (30 10), POINT (40 40), POINT (20 20), POINT (10 30), POINT (10 10), POINT (20 50))
ST_ForcePolygonCCW¶
Introduction: For (Multi)Polygon geometries, this function sets the exterior ring orientation to counter-clockwise and interior rings to clockwise orientation. Non-polygonal geometries are returned unchanged.
Format: ST_ForcePolygonCCW(geom: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_AsText(ST_ForcePolygonCCW(ST_GeomFromText('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))')))
Output:
POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))
ST_ForcePolygonCW¶
Introduction: For (Multi)Polygon geometries, this function sets the exterior ring orientation to clockwise and interior rings to counter-clockwise orientation. Non-polygonal geometries are returned unchanged.
Format: ST_ForcePolygonCW(geom: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_AsText(ST_ForcePolygonCW(ST_GeomFromText('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20))')))
Output:
POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))
ST_ForceRHR¶
Introduction: Sets the orientation of polygon vertex orderings to follow the Right-Hand-Rule convention. The exterior ring will have a clockwise winding order, while any interior rings are oriented counter-clockwise. This ensures the area bounded by the polygon falls on the right-hand side relative to the ring directions. The function is an alias for ST_ForcePolygonCW.
Format: ST_ForceRHR(geom: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_AsText(ST_ForceRHR(ST_GeomFromText('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35),(30 20, 20 15, 20 25, 30 20))')))
Output:
POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))
ST_FrechetDistance¶
Introduction: Computes and returns discrete Frechet Distance between the given two geometries, based on Computing Discrete Frechet Distance
If any of the geometries is empty, returns 0.0
Format: ST_FrechetDistance(g1: Geometry, g2: Geometry)
Since: v1.5.0
Example:
SELECT ST_FrechetDistance(ST_GeomFromWKT('POINT (0 1)'), ST_GeomFromWKT('LINESTRING (0 0, 1 0, 2 0, 3 0, 4 0, 5 0)'))
Output:
5.0990195135927845
ST_GeneratePoints¶
Introduction: Generates a specified quantity of pseudo-random points within the boundaries of the provided polygonal geometry. When seed is either zero or not defined then output will be random.
Format:
ST_GeneratePoints(geom: Geometry, numPoints: Integer, seed: Long = 0)
ST_GeneratePoints(geom: Geometry, numPoints: Integer)
Since: v1.6.1
SQL Example:
SELECT ST_GeneratePoints(
ST_GeomFromWKT('POLYGON((0 0, 1 0, 1 1, 0 1, 0 0))'), 4
)
Output:
Note
Due to the pseudo-random nature of point generation, the output of this function will vary between executions and may not match any provided examples.
MULTIPOINT ((0.2393028905520183 0.9721563442837837), (0.3805848547053376 0.7546556656982678), (0.0950295778200995 0.2494334895495989), (0.4133520939987385 0.3447046312451945))
ST_GeoHash¶
Introduction: Returns GeoHash of the geometry with given precision
Format: ST_GeoHash(geom: Geometry, precision: Integer)
Since: v1.2.0
Example:
SELECT ST_GeoHash(ST_GeomFromText('POINT(21.427834 52.042576573)'), 5) AS geohash
Output:
u3r0p
ST_GeometricMedian¶
Introduction: Computes the approximate geometric median of a MultiPoint geometry using the Weiszfeld algorithm. The geometric median provides a centrality measure that is less sensitive to outlier points than the centroid.
The algorithm will iterate until the distance change between successive iterations is less than the supplied tolerance parameter. If this condition has not been met after maxIter iterations, the function will produce an error and exit, unless failIfNotConverged is set to false.
If a tolerance value is not provided, a default tolerance value is 1e-6.
Format:
ST_GeometricMedian(geom: Geometry, tolerance: Double, maxIter: Integer, failIfNotConverged: Boolean)
ST_GeometricMedian(geom: Geometry, tolerance: Double, maxIter: Integer)
ST_GeometricMedian(geom: Geometry, tolerance: Double)
ST_GeometricMedian(geom: Geometry)
Default parameters: tolerance: 1e-6, maxIter: 1000, failIfNotConverged: false
Since: v1.4.1
Example:
SELECT ST_GeometricMedian(ST_GeomFromWKT('MULTIPOINT((0 0), (1 1), (2 2), (200 200))'))
Output:
POINT (1.9761550281255005 1.9761550281255005)
ST_GeometryN¶
Introduction: Return the 0-based Nth geometry if the geometry is a GEOMETRYCOLLECTION, (MULTI)POINT, (MULTI)LINESTRING, MULTICURVE or (MULTI)POLYGON. Otherwise, return null
Format: ST_GeometryN(geom: Geometry, n: Integer)
Since: v1.3.0
Example:
SELECT ST_GeometryN(ST_GeomFromText('MULTIPOINT((1 2), (3 4), (5 6), (8 9))'), 1)
Output:
POINT (3 4)
ST_GeometryType¶
Introduction: Returns the type of the geometry as a string. EG: 'ST_Linestring', 'ST_Polygon' etc.
Format: ST_GeometryType (A: Geometry)
Since: v1.5.0
Example:
SELECT ST_GeometryType(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)'))
Output:
ST_LINESTRING
ST_H3CellDistance¶
Introduction: return result of h3 function gridDistance(cel1, cell2). As described by H3 documentation
Finding the distance can fail because the two indexes are not comparable (different resolutions), too far apart, or are separated by pentagonal distortion. This is the same set of limitations as the local IJ coordinate space functions.
In this case, Sedona use in-house implementation of estimation the shortest path and return the size as distance.
Format: ST_H3CellDistance(cell1: Long, cell2: Long)
Since: v1.5.0
Example:
select ST_H3CellDistance(ST_H3CellIDs(ST_GeomFromWKT('POINT(1 2)'), 8, true)[1], ST_H3CellIDs(ST_GeomFromWKT('POINT(1.23 1.59)'), 8, true)[1])
Output:
+----+----------------------+
| op | EXPR$0 |
+----+----------------------+
| +I | 78 |
+----+----------------------+
ST_H3CellIDs¶
Introduction: Cover the geometry by H3 cell IDs with the given resolution(level). To understand the cell statistics please refer to H3 Doc H3 native fill functions doesn't guarantee full coverage on the shapes.
Cover Polygon¶
When fullCover = false, for polygon sedona will use polygonToCells. This can't guarantee full coverage but will guarantee no false positive.
When fullCover = true, sedona will add on extra traversal logic to guarantee full coverage on shapes. This will lead to redundancy but can guarantee full coverage.
Choose the option according to your use case.
Cover LineString¶
For the lineString, sedona will call gridPathCells(https://h3geo.org/docs/api/traversal#gridpathcells) per segment. From H3's documentation
This function may fail to find the line between two indexes, for example if they are very far apart. It may also fail when finding distances for indexes on opposite sides of a pentagon.
When the gridPathCells function throw error, Sedona implemented in-house approximate implementation to generate the shortest path, which can cover the corner cases.
Both functions can't guarantee full coverage. When the fullCover = true, we'll do extra cell traversal to guarantee full cover.
In worst case, sedona will use MBR to guarantee the full coverage.
If you seek to get the shortest path between cells, you can call this function with fullCover = false
Format: ST_H3CellIDs(geom: geometry, level: Int, fullCover: true)
Since: v1.5.0
Example:
SELECT ST_H3CellIDs(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'), 6, true)
Output:
+----+--------------------------------+
| op | EXPR$0 |
+----+--------------------------------+
| +I | [605547539457900543, 605547... |
+----+--------------------------------+
ST_H3KRing¶
Introduction: return the result of H3 function gridDisk(cell, k).
K means the distance of the origin index, gridDisk(cell, k) return cells with distance <=k from the original cell.
exactRing : Boolean, when set to true, sedona will remove the result of gridDisk(cell, k-1) from the original results,
means only keep the cells with distance exactly k from the original cell
Format: ST_H3KRing(cell: Long, k: Int, exactRing: Boolean)
Since: v1.5.0
Example:
select ST_H3KRing(ST_H3CellIDs(ST_GeomFromWKT('POINT(1 2)'), 8, true)[1], 1, false), ST_H3KRing(ST_H3CellIDs(ST_GeomFromWKT('POINT(1 2)'), 8, true)[1], 1, true)
Output:
+----+--------------------------------+--------------------------------+
| op | EXPR$0 | EXPR$1 |
+----+--------------------------------+--------------------------------+
| +I | [614552609325318143, 614552... | [614552597293957119, 614552... |
+----+--------------------------------+--------------------------------+
ST_H3ToGeom¶
Introduction: Return the result of H3 function cellsToMultiPolygon(cells).
Converts an array of Uber H3 cell indices into an array of Polygon geometries, where each polygon represents a hexagonal H3 cell.
Hint
To convert a Polygon array to MultiPolygon, use ST_Collect. However, the result may be an invalid geometry. Apply ST_MakeValid to the ST_Collect output to ensure a valid MultiPolygon.
An alternative approach to consolidate a Polygon array into a Polygon/MultiPolygon, use the ST_Union function.
Format: ST_H3ToGeom(cells: Array[Long])
Since: v1.6.0
Example:
SELECT ST_H3ToGeom(ST_H3CellIDs(ST_GeomFromWKT('POINT(1 2)'), 8, true)[0], 1, true))
Output:
[POLYGON ((1.0057629565405093 1.9984665139177547, 1.0037116327309097 2.0018325249140068, 0.999727799357053 2.001163270465665, 0.9977951427833316 1.997128228393235, 0.9998461908217928 1.993762152933182, 1.0038301712104316 1.9944311839965523, 1.0057629565405093 1.9984665139177547))]
ST_HasM¶
Introduction: Checks for the presence of M coordinate values representing measures or linear references. Returns true if the input geometry includes an M coordinate, false otherwise.
Format: ST_HasM(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_HasM(
ST_GeomFromWKT('POLYGON ZM ((30 10 5 1, 40 40 10 2, 20 40 15 3, 10 20 20 4, 30 10 5 1))')
)
Output:
True
ST_HasZ¶
Introduction: Checks for the presence of Z coordinate values representing measures or linear references. Returns true if the input geometry includes an Z coordinate, false otherwise.
Format: ST_HasZ(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_HasZ(
ST_GeomFromWKT('LINESTRING Z (30 10 5, 40 40 10, 20 40 15, 10 20 20)')
)
Output:
True
ST_HausdorffDistance¶
Introduction: Returns a discretized (and hence approximate) Hausdorff distance between the given 2 geometries. Optionally, a densityFraction parameter can be specified, which gives more accurate results by densifying segments before computing hausdorff distance between them. Each segment is broken down into equal-length subsegments whose ratio with segment length is closest to the given density fraction.
Hence, the lower the densityFrac value, the more accurate is the computed hausdorff distance, and the more time it takes to compute it.
If any of the geometry is empty, 0.0 is returned.
Note
Accepted range of densityFrac is (0.0, 1.0], if any other value is provided, ST_HausdorffDistance throws an IllegalArgumentException
Note
Even though the function accepts 3D geometry, the z ordinate is ignored and the computed hausdorff distance is equivalent to the geometries not having the z ordinate.
Format: ST_HausdorffDistance(g1: Geometry, g2: Geometry, densityFrac: Double)
Since: v1.5.0
Example:
SELECT ST_HausdorffDistance(ST_GeomFromWKT('POINT (0.0 1.0)'), ST_GeomFromWKT('LINESTRING (0 0, 1 0, 2 0, 3 0, 4 0, 5 0)'), 0.1)
Output:
5.0990195135927845
Example:
SELECT ST_HausdorffDistance(ST_GeomFromText('POLYGON Z((1 0 1, 1 1 2, 2 1 5, 2 0 1, 1 0 1))'), ST_GeomFromText('POLYGON Z((4 0 4, 6 1 4, 6 4 9, 6 1 3, 4 0 4))'))
Output:
5.0
ST_InteriorRingN¶
Introduction: Returns the Nth interior linestring ring of the polygon geometry. Returns NULL if the geometry is not a polygon or the given N is out of range
Format: ST_InteriorRingN(geom: Geometry, n: Integer)
Since: v1.3.0
Example:
SELECT ST_InteriorRingN(ST_GeomFromText('POLYGON((0 0, 0 5, 5 5, 5 0, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1), (1 3, 2 3, 2 4, 1 4, 1 3), (3 3, 4 3, 4 4, 3 4, 3 3))'), 0)
Output:
LINEARRING (1 1, 2 1, 2 2, 1 2, 1 1)
ST_Intersection¶
Introduction: Return the intersection geometry of A and B
Format: ST_Intersection (A: Geometry, B: Geometry)
Since: v1.5.0
Example:
SELECT ST_Intersection(
ST_GeomFromWKT("POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))"),
ST_GeomFromWKT("POLYGON((2 2, 9 2, 9 9, 2 9, 2 2))")
)
Output:
POLYGON ((2 8, 8 8, 8 2, 2 2, 2 8))
ST_IsClosed¶
Introduction: RETURNS true if the LINESTRING start and end point are the same.
Format: ST_IsClosed(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_IsClosed(ST_GeomFromText('LINESTRING(0 0, 1 1, 1 0)'))
Output:
false
ST_IsCollection¶
Introduction: Returns TRUE if the geometry type of the input is a geometry collection type.
Collection types are the following:
- GEOMETRYCOLLECTION
- MULTI{POINT, POLYGON, LINESTRING}
Format: ST_IsCollection(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_IsCollection(ST_GeomFromText('MULTIPOINT(0 0), (6 6)'))
Output:
true
Example:
SELECT ST_IsCollection(ST_GeomFromText('POINT(5 5)'))
Output:
false
ST_IsEmpty¶
Introduction: Test if a geometry is empty geometry
Format: ST_IsEmpty (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_IsEmpty(ST_GeomFromWKT('POLYGON((0 0,0 1,1 1,1 0,0 0))'))
Output:
false
ST_IsPolygonCCW¶
Introduction: Returns true if all polygonal components in the input geometry have their exterior rings oriented counter-clockwise and interior rings oriented clockwise.
Format: ST_IsPolygonCCW(geom: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_IsPolygonCCW(ST_GeomFromWKT('POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20, 20 35), (30 20, 20 15, 20 25, 30 20))'))
Output:
true
ST_IsPolygonCW¶
Introduction: Returns true if all polygonal components in the input geometry have their exterior rings oriented counter-clockwise and interior rings oriented clockwise.
Format: ST_IsPolygonCW(geom: Geometry)
Since: v1.6.0
SQL Example:
SELECT ST_IsPolygonCW(ST_GeomFromWKT('POLYGON ((20 35, 45 20, 30 5, 10 10, 10 30, 20 35), (30 20, 20 25, 20 15, 30 20))'))
Output:
true
ST_IsRing¶
Introduction: RETURN true if LINESTRING is ST_IsClosed and ST_IsSimple.
Format: ST_IsRing(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_IsRing(ST_GeomFromText("LINESTRING(0 0, 0 1, 1 1, 1 0, 0 0)"))
Output:
true
ST_IsSimple¶
Introduction: Test if geometry's only self-intersections are at boundary points.
Format: ST_IsSimple (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_IsSimple(ST_GeomFromWKT('POLYGON((1 1, 3 1, 3 3, 1 3, 1 1))'))
Output:
true
ST_IsValid¶
Introduction: Test if a geometry is well-formed. The function can be invoked with just the geometry or with an additional flag (from v1.5.1). The flag alters the validity checking behavior. The flags parameter is a bitfield with the following options:
- 0 (default): Use usual OGC SFS (Simple Features Specification) validity semantics.
- 1: "ESRI flag", Accepts certain self-touching rings as valid, which are considered invalid under OGC standards.
Formats:
ST_IsValid (A: Geometry)
ST_IsValid (A: Geometry, flag: Integer)
Since: v1.0.0
SQL Example:
SELECT ST_IsValid(ST_GeomFromWKT('POLYGON((0 0, 10 0, 10 10, 0 10, 0 0), (15 15, 15 20, 20 20, 20 15, 15 15))'))
Output:
false
ST_IsValidReason¶
Introduction: Returns text stating if the geometry is valid. If not, it provides a reason why it is invalid. The function can be invoked with just the geometry or with an additional flag. The flag alters the validity checking behavior. The flags parameter is a bitfield with the following options:
- 0 (default): Use usual OGC SFS (Simple Features Specification) validity semantics.
- 1: "ESRI flag", Accepts certain self-touching rings as valid, which are considered invalid under OGC standards.
Formats:
ST_IsValidReason (A: Geometry)
ST_IsValidReason (A: Geometry, flag: Integer)
Since: v1.5.1
SQL Example for valid geometry:
SELECT ST_IsValidReason(ST_GeomFromWKT('POLYGON ((100 100, 100 300, 300 300, 300 100, 100 100))')) as validity_info
Output:
Valid Geometry
SQL Example for invalid geometries:
SELECT gid, ST_IsValidReason(geom) as validity_info
FROM Geometry_table
WHERE ST_IsValid(geom) = false
ORDER BY gid
Output:
gid | validity_info
-----+----------------------------------------------------
5330 | Self-intersection at or near point (32.0, 5.0, NaN)
5340 | Self-intersection at or near point (42.0, 5.0, NaN)
5350 | Self-intersection at or near point (52.0, 5.0, NaN)
ST_IsValidTrajectory¶
Introduction: This function checks if a geometry is a valid trajectory representation. For a trajectory to be considered valid, it must be a LineString that includes measure (M) values. The key requirement is that the M values increase from one vertex to the next as you move along the line.
Format: ST_IsValidTrajectory(geom: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_IsValidTrajectory(
ST_GeomFromText('LINESTRING M (0 0 1, 0 1 2)')
)
Output:
true
SQL Example:
SELECT ST_IsValidTrajectory(
ST_GeomFromText('LINESTRING M (0 0 1, 0 1 0)')
)
Output:
false
ST_Length¶
Introduction: Returns the perimeter of A.
Format: ST_Length (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_Length(ST_GeomFromWKT('LINESTRING(38 16,38 50,65 50,66 16,38 16)'))
Output:
123.0147027033899
ST_Length2D¶
Introduction: Returns the perimeter of A. This function is an alias of ST_Length.
Format: ST_Length2D (A:geometry)
Since: v1.6.1
Example:
SELECT ST_Length2D(ST_GeomFromWKT('LINESTRING(38 16,38 50,65 50,66 16,38 16)'))
Output:
123.0147027033899
ST_LengthSpheroid¶
Introduction: Return the geodesic perimeter of A using WGS84 spheroid. Unit is meter. Works better for large geometries (country level) compared to ST_Length + ST_Transform. It is equivalent to PostGIS ST_Length(geography, use_spheroid=true) and ST_LengthSpheroid function and produces nearly identical results.
Geometry must be in EPSG:4326 (WGS84) projection and must be in lon/lat order. You can use ST_FlipCoordinates to swap lat and lon.
Note
By default, this function uses lon/lat order since v1.5.0. Before, it used lat/lon order.
Format: ST_LengthSpheroid (A: Geometry)
Since: v1.4.1
Example:
SELECT ST_LengthSpheroid(ST_GeomFromWKT('Polygon ((0 0, 90 0, 0 0))'))
Output:
20037508.342789244
ST_LineFromMultiPoint¶
Introduction: Creates a LineString from a MultiPoint geometry.
Format: ST_LineFromMultiPoint (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_LineFromMultiPoint(ST_GeomFromText('MULTIPOINT((10 40), (40 30), (20 20), (30 10))'))
Output:
LINESTRING (10 40, 40 30, 20 20, 30 10)
ST_LineInterpolatePoint¶
Introduction: Returns a point interpolated along a line. First argument must be a LINESTRING. Second argument is a Double between 0 and 1 representing fraction of total linestring length the point has to be located.
Format: ST_LineInterpolatePoint (geom: Geometry, fraction: Double)
Since: v1.5.0
Example:
SELECT ST_LineInterpolatePoint(ST_GeomFromWKT('LINESTRING(25 50, 100 125, 150 190)'), 0.2)
Output:
POINT (51.5974135047432 76.5974135047432)
ST_LineLocatePoint¶
Introduction: Returns a double between 0 and 1, representing the location of the closest point on the LineString as a fraction of its total length. The first argument must be a LINESTRING, and the second argument is a POINT geometry.
Format: ST_LineLocatePoint(linestring: Geometry, point: Geometry)
Since: v1.5.1
SQL Example:
SELECT ST_LineLocatePoint(ST_GeomFromWKT('LINESTRING(0 0, 1 1, 2 2)'), ST_GeomFromWKT('POINT(0 2)'))
Output:
0.5
ST_LineMerge¶
Introduction: Returns a LineString formed by sewing together the constituent line work of a MULTILINESTRING.
Note
Only works for MULTILINESTRING. Using other geometry will return a GEOMETRYCOLLECTION EMPTY. If the MultiLineString can't be merged, the original MULTILINESTRING is returned.
Format: ST_LineMerge (A: Geometry)
Since: v1.5.0
Example:
SELECT ST_LineMerge(ST_GeomFromWKT('MULTILINESTRING ((-29 -27, -30 -29.7, -45 -33), (-45 -33, -46 -32))'))
Output:
LINESTRING (-29 -27, -30 -29.7, -45 -33, -46 -32)
ST_LineSubstring¶
Introduction: Return a linestring being a substring of the input one starting and ending at the given fractions of total 2d length. Second and third arguments are Double values between 0 and 1. This only works with LINESTRINGs.
Format: ST_LineSubstring (geom: Geometry, startfraction: Double, endfraction: Double)
Since: v1.5.0
Example:
SELECT ST_LineSubstring(ST_GeomFromWKT('LINESTRING(25 50, 100 125, 150 190)'), 0.333, 0.666)
Output:
LINESTRING (69.28469348539744 94.28469348539744, 100 125, 111.70035626068274 140.21046313888758)
ST_LocateAlong¶
Introduction: This function computes Point or MultiPoint geometries representing locations along a measured input geometry (LineString or MultiLineString) corresponding to the provided measure value(s). Polygonal geometry inputs are not supported. The output points lie directly on the input line at the specified measure positions.
Additionally, an optional offset parameter can shift the resulting points left or right from the input line. A positive offset displaces the points to the left side, while a negative value offsets them to the right side by the given distance.
This allows identifying precise locations along a measured linear geometry based on supplied measure values, with the ability to offset the output points if needed.
Format:
ST_LocateAlong(linear: Geometry, measure: Double, offset: Double)
ST_LocateAlong(linear: Geometry, measure: Double)
Since: v1.6.1
SQL Example:
SELECT ST_LocateAlong(
ST_GeomFromText('LINESTRING M (10 30 1, 50 50 1, 30 110 2, 70 90 2, 180 140 3, 130 190 3)')
)
Output:
MULTIPOINT M((30 110 2), (50 100 2), (70 90 2))
ST_LongestLine¶
Introduction: Returns the LineString geometry representing the maximum distance between any two points from the input geometries.
Format: ST_LongestLine(geom1: Geometry, geom2: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_LongestLine(
ST_GeomFromText("POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))"),
ST_GeomFromText("POLYGON ((10 20, 30 30, 40 20, 30 10, 10 20))")
)
Output:
LINESTRING (40 40, 10 20)
ST_M¶
Introduction: Returns M Coordinate of given Point, null otherwise.
Format: ST_M(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_M(ST_MakePoint(1, 2, 3, 4))
Output:
4.0
ST_MMax¶
Introduction: Returns M maxima of the given geometry or null if there is no M coordinate.
Format: ST_MMax(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_MMax(
ST_GeomFromWKT('POLYGON ZM ((30 10 5 1, 40 40 10 2, 20 40 15 3, 10 20 20 4, 30 10 5 1))')
)
Output:
4.0
ST_MMin¶
Introduction: Returns M minima of the given geometry or null if there is no M coordinate.
Format: ST_MMin(geom: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_MMin(
ST_GeomFromWKT('LINESTRING ZM(1 1 1 1, 2 2 2 2, 3 3 3 3, -1 -1 -1 -1)')
)
Output:
-1.0
ST_MakeLine¶
Introduction: Creates a LineString containing the points of Point, MultiPoint, or LineString geometries. Other geometry types cause an error.
Format:
ST_MakeLine(geom1: Geometry, geom2: Geometry)
ST_MakeLine(geoms: ARRAY[Geometry])
Since: v1.5.0
Example:
SELECT ST_AsText( ST_MakeLine(ST_Point(1,2), ST_Point(3,4)) );
Output:
LINESTRING(1 2,3 4)
Example:
SELECT ST_AsText( ST_MakeLine( 'LINESTRING(0 0, 1 1)', 'LINESTRING(2 2, 3 3)' ) );
Output:
LINESTRING(0 0,1 1,2 2,3 3)
ST_MakePolygon¶
Introduction: Function to convert closed linestring to polygon including holes
Format: ST_MakePolygon(geom: Geometry, holes: ARRAY[Geometry])
Since: v1.5.0
Example:
SELECT ST_MakePolygon(
ST_GeomFromText('LINESTRING(7 -1, 7 6, 9 6, 9 1, 7 -1)'),
ARRAY(ST_GeomFromText('LINESTRING(6 2, 8 2, 8 1, 6 1, 6 2)'))
)
Output:
POLYGON ((7 -1, 7 6, 9 6, 9 1, 7 -1), (6 2, 8 2, 8 1, 6 1, 6 2))
ST_MakeValid¶
Introduction: Given an invalid geometry, create a valid representation of the geometry.
Collapsed geometries are either converted to empty (keepCollapsed=true) or a valid geometry of lower dimension (keepCollapsed=false). Default is keepCollapsed=false.
Format:
ST_MakeValid (A: Geometry)
ST_MakeValid (A: Geometry, keepCollapsed: Boolean)
Since: v1.5.0
Example:
WITH linestring AS (
SELECT ST_GeomFromWKT('LINESTRING(1 1, 1 1)') AS geom
) SELECT ST_MakeValid(geom), ST_MakeValid(geom, true) FROM linestring
Result:
+------------------+------------------------+
|st_makevalid(geom)|st_makevalid(geom, true)|
+------------------+------------------------+
| LINESTRING EMPTY| POINT (1 1)|
+------------------+------------------------+
ST_MaxDistance¶
Introduction: Calculates and returns the length value representing the maximum distance between any two points across the input geometries. This function is an alias for ST_LongestDistance.
Format: ST_MaxDistance(geom1: Geometry, geom2: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_MaxDistance(
ST_GeomFromText("POLYGON ((30 10, 40 40, 20 40, 10 20, 30 10))"),
ST_GeomFromText("POLYGON ((10 20, 30 30, 40 20, 30 10, 10 20))")
)
Output:
36.05551275463989
ST_MinimumClearance¶
Introduction: The minimum clearance is a metric that quantifies a geometry's tolerance to changes in coordinate precision or vertex positions. It represents the maximum distance by which vertices can be adjusted without introducing invalidity to the geometry's structure. A larger minimum clearance value indicates greater robustness against such perturbations.
For a geometry with a minimum clearance of x, the following conditions hold:
- No two distinct vertices are separated by a distance less than
x. - No vertex lies within a distance
xfrom any line segment it is not an endpoint of.
For geometries with no definable minimum clearance, such as single Point geometries or MultiPoint geometries where all points occupy the same location, the function returns Double.MAX_VALUE.
Format: ST_MinimumClearance(geometry: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_MinimumClearance(
ST_GeomFromWKT('POLYGON ((65 18, 62 16, 64.5 16, 62 14, 65 14, 65 18))')
)
Output:
0.5
ST_MinimumClearanceLine¶
Introduction: This function returns a two-point LineString geometry representing the minimum clearance distance of the input geometry. If the input geometry does not have a defined minimum clearance, such as for single Points or coincident MultiPoints, an empty LineString geometry is returned instead.
Format: ST_MinimumClearanceLine(geometry: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_MinimumClearanceLine(
ST_GeomFromWKT('POLYGON ((65 18, 62 16, 64.5 16, 62 14, 65 14, 65 18))')
)
Output:
LINESTRING (64.5 16, 65 16)
ST_MinimumBoundingCircle¶
Introduction: Returns the smallest circle polygon that contains a geometry. The optional quadrantSegments parameter determines how many segments to use per quadrant and the default number of segments is 48.
Format:
ST_MinimumBoundingCircle(geom: Geometry, [Optional] quadrantSegments: Integer)
Since: v1.5.0
Example:
SELECT ST_MinimumBoundingCircle(ST_GeomFromWKT('LINESTRING(0 0, 0 1)'))
Output:
POLYGON ((0.5 0.5, 0.4997322937381828 0.4836404585891119, 0.4989294616193017 0.4672984353849285, 0.4975923633360985 0.4509914298352197, 0.4957224306869052 0.4347369038899742, 0.4933216660424395 0.4185522633027057, 0.4903926402016152 0.4024548389919359, 0.4869384896386668 0.3864618684828134, 0.4829629131445342 0.3705904774487396, 0.4784701678661044 0.3548576613727689, 0.4734650647475528 0.3392802673484192, 0.4679529633786629 0.3238749760393833, 0.4619397662556434 0.3086582838174551, 0.4554319124605879 0.2936464850978027, 0.4484363707663442 0.2788556548904993, 0.4409606321741775 0.2643016315870012, 0.4330127018922194 0.25, 0.4246010907632894 0.2359660746748161, 0.4157348061512726 0.2222148834901989, 0.4064233422958076 0.2087611515660989, 0.3966766701456176 0.1956192854956397, 0.3865052266813685 0.1828033579181773, 0.3759199037394887 0.1703270924499656, 0.3649320363489179 0.1582038489885644, 0.3535533905932738 0.1464466094067263, 0.3417961510114357 0.1350679636510822, 0.3296729075500345 0.1240800962605114, 0.3171966420818228 0.1134947733186316, 0.3043807145043603 0.1033233298543824, 0.2912388484339011 0.0935766577041924, 0.2777851165098012 0.0842651938487274, 0.264033925325184 0.0753989092367106, 0.2500000000000001 0.0669872981077807, 0.2356983684129989 0.0590393678258225, 0.2211443451095007 0.0515636292336559, 0.2063535149021975 0.0445680875394122, 0.1913417161825449 0.0380602337443566, 0.1761250239606168 0.0320470366213372, 0.1607197326515808 0.0265349352524472, 0.1451423386272312 0.0215298321338956, 0.1294095225512605 0.0170370868554659, 0.1135381315171867 0.0130615103613332, 0.0975451610080642 0.0096073597983848, 0.0814477366972944 0.0066783339575605, 0.0652630961100259 0.0042775693130948, 0.0490085701647804 0.0024076366639016, 0.0327015646150716 0.0010705383806983, 0.0163595414108882 0.0002677062618172, 0 0, -0.016359541410888 0.0002677062618172, -0.0327015646150715 0.0010705383806983, -0.0490085701647802 0.0024076366639015, -0.0652630961100257 0.0042775693130948, -0.0814477366972942 0.0066783339575605, -0.097545161008064 0.0096073597983847, -0.1135381315171866 0.0130615103613332, -0.1294095225512603 0.0170370868554658, -0.1451423386272311 0.0215298321338955, -0.1607197326515807 0.0265349352524472, -0.1761250239606166 0.0320470366213371, -0.1913417161825448 0.0380602337443566, -0.2063535149021973 0.044568087539412, -0.2211443451095006 0.0515636292336558, -0.2356983684129987 0.0590393678258224, -0.2499999999999999 0.0669872981077806, -0.264033925325184 0.0753989092367106, -0.277785116509801 0.0842651938487273, -0.291238848433901 0.0935766577041924, -0.3043807145043602 0.1033233298543823, -0.3171966420818227 0.1134947733186314, -0.3296729075500343 0.1240800962605111, -0.3417961510114356 0.1350679636510821, -0.3535533905932737 0.1464466094067262, -0.3649320363489177 0.1582038489885642, -0.3759199037394886 0.1703270924499655, -0.3865052266813683 0.1828033579181771, -0.3966766701456175 0.1956192854956396, -0.4064233422958076 0.2087611515660989, -0.4157348061512725 0.2222148834901987, -0.4246010907632894 0.235966074674816, -0.4330127018922192 0.2499999999999998, -0.4409606321741775 0.264301631587001, -0.4484363707663441 0.2788556548904991, -0.4554319124605878 0.2936464850978025, -0.4619397662556434 0.3086582838174551, -0.4679529633786628 0.3238749760393831, -0.4734650647475528 0.3392802673484191, -0.4784701678661044 0.3548576613727686, -0.4829629131445341 0.3705904774487395, -0.4869384896386668 0.3864618684828132, -0.4903926402016152 0.4024548389919357, -0.4933216660424395 0.4185522633027056, -0.4957224306869052 0.434736903889974, -0.4975923633360984 0.4509914298352196, -0.4989294616193017 0.4672984353849282, -0.4997322937381828 0.4836404585891118, -0.5 0.4999999999999999, -0.4997322937381828 0.5163595414108879, -0.4989294616193017 0.5327015646150715, -0.4975923633360985 0.5490085701647801, -0.4957224306869052 0.5652630961100257, -0.4933216660424395 0.5814477366972941, -0.4903926402016153 0.597545161008064, -0.4869384896386668 0.6135381315171865, -0.4829629131445342 0.6294095225512601, -0.4784701678661045 0.645142338627231, -0.4734650647475529 0.6607197326515806, -0.4679529633786629 0.6761250239606166, -0.4619397662556435 0.6913417161825446, -0.455431912460588 0.7063535149021972, -0.4484363707663442 0.7211443451095005, -0.4409606321741776 0.7356983684129986, -0.4330127018922194 0.7499999999999999, -0.4246010907632896 0.7640339253251838, -0.4157348061512727 0.777785116509801, -0.4064233422958078 0.7912388484339008, -0.3966766701456177 0.8043807145043602, -0.3865052266813686 0.8171966420818226, -0.3759199037394889 0.8296729075500342, -0.3649320363489179 0.8417961510114356, -0.353553390593274 0.8535533905932735, -0.3417961510114358 0.8649320363489177, -0.3296729075500345 0.8759199037394887, -0.317196642081823 0.8865052266813683, -0.3043807145043604 0.8966766701456175, -0.2912388484339011 0.9064233422958076, -0.2777851165098015 0.9157348061512725, -0.2640339253251843 0.9246010907632893, -0.2500000000000002 0.9330127018922192, -0.235698368412999 0.9409606321741775, -0.2211443451095007 0.9484363707663441, -0.2063535149021977 0.9554319124605877, -0.1913417161825452 0.9619397662556433, -0.176125023960617 0.9679529633786628, -0.1607197326515809 0.9734650647475528, -0.1451423386272312 0.9784701678661044, -0.1294095225512608 0.9829629131445341, -0.1135381315171869 0.9869384896386668, -0.0975451610080643 0.9903926402016152, -0.0814477366972945 0.9933216660424395, -0.0652630961100262 0.9957224306869051, -0.0490085701647807 0.9975923633360984, -0.0327015646150718 0.9989294616193017, -0.0163595414108883 0.9997322937381828, -0.0000000000000001 1, 0.0163595414108876 0.9997322937381828, 0.0327015646150712 0.9989294616193019, 0.04900857016478 0.9975923633360985, 0.0652630961100256 0.9957224306869052, 0.0814477366972943 0.9933216660424395, 0.0975451610080637 0.9903926402016153, 0.1135381315171863 0.9869384896386669, 0.1294095225512601 0.9829629131445342, 0.145142338627231 0.9784701678661045, 0.1607197326515807 0.9734650647475529, 0.1761250239606164 0.967952963378663, 0.1913417161825446 0.9619397662556435, 0.2063535149021972 0.955431912460588, 0.2211443451095005 0.9484363707663442, 0.2356983684129984 0.9409606321741777, 0.2499999999999997 0.9330127018922195, 0.2640339253251837 0.9246010907632896, 0.2777851165098009 0.9157348061512727, 0.291238848433901 0.9064233422958077, 0.3043807145043599 0.8966766701456179, 0.3171966420818225 0.8865052266813687, 0.3296729075500342 0.8759199037394889, 0.3417961510114355 0.8649320363489179, 0.3535533905932737 0.8535533905932738, 0.3649320363489175 0.841796151011436, 0.3759199037394885 0.8296729075500346, 0.3865052266813683 0.817196642081823, 0.3966766701456175 0.8043807145043604, 0.4064233422958076 0.7912388484339011, 0.4157348061512723 0.7777851165098015, 0.4246010907632893 0.7640339253251842, 0.4330127018922192 0.7500000000000002, 0.4409606321741774 0.735698368412999, 0.4484363707663439 0.7211443451095011, 0.4554319124605877 0.7063535149021978, 0.4619397662556433 0.6913417161825453, 0.4679529633786628 0.676125023960617, 0.4734650647475528 0.6607197326515809, 0.4784701678661043 0.6451423386272317, 0.482962913144534 0.6294095225512608, 0.4869384896386668 0.613538131517187, 0.4903926402016152 0.5975451610080643, 0.4933216660424395 0.5814477366972945, 0.4957224306869051 0.5652630961100262, 0.4975923633360984 0.5490085701647807, 0.4989294616193017 0.5327015646150718, 0.4997322937381828 0.5163595414108882, 0.5 0.5))
ST_MinimumBoundingRadius¶
Introduction: Returns a struct containing the center point and radius of the smallest circle that contains a geometry.
Format: ST_MinimumBoundingRadius(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_MinimumBoundingRadius(ST_GeomFromText('POLYGON((1 1,0 0, -1 1, 1 1))'))
Output:
{POINT (0 1), 1.0}
ST_Multi¶
Introduction: Returns a MultiGeometry object based on the geometry input. ST_Multi is basically an alias for ST_Collect with one geometry.
Format: ST_Multi(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_Multi(ST_GeomFromText('POINT(1 1)'))
Output:
MULTIPOINT (1 1)
ST_Normalize¶
Introduction: Returns the input geometry in its normalized form.
Format: ST_Normalize(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_AsEWKT(ST_Normalize(ST_GeomFromWKT('POLYGON((0 1, 1 1, 1 0, 0 0, 0 1))')))
Result:
POLYGON ((0 0, 0 1, 1 1, 1 0, 0 0))
ST_NPoints¶
Introduction: Returns the number of points of the geometry
Format: ST_NPoints (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_NPoints(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)'))
Output:
4
ST_NDims¶
Introduction: Returns the coordinate dimension of the geometry.
Format: ST_NDims(geom: Geometry)
Since: v1.3.1
Example with z coordinate:
SELECT ST_NDims(ST_GeomFromEWKT('POINT(1 1 2)'))
Output:
3
Example with x,y coordinate:
SELECT ST_NDims(ST_GeomFromText('POINT(1 1)'))
Output:
2
ST_NRings¶
Introduction: Returns the number of rings in a Polygon or MultiPolygon. Contrary to ST_NumInteriorRings, this function also takes into account the number of exterior rings.
This function returns 0 for an empty Polygon or MultiPolygon. If the geometry is not a Polygon or MultiPolygon, an IllegalArgument Exception is thrown.
Format: ST_NRings(geom: Geometry)
Since: v1.4.1
Examples:
Input: POLYGON ((1 0, 1 1, 2 1, 2 0, 1 0))
Output: 1
Input: 'MULTIPOLYGON (((1 0, 1 6, 6 6, 6 0, 1 0), (2 1, 2 2, 3 2, 3 1, 2 1)), ((10 0, 10 6, 16 6, 16 0, 10 0), (12 1, 12 2, 13 2, 13 1, 12 1)))'
Output: 4
Input: 'POLYGON EMPTY'
Output: 0
Input: 'LINESTRING (1 0, 1 1, 2 1)'
Output: Unsupported geometry type: LineString, only Polygon or MultiPolygon geometries are supported.
ST_NumGeometries¶
Introduction: Returns the number of Geometries. If geometry is a GEOMETRYCOLLECTION (or MULTI*) return the number of geometries, for single geometries will return 1.
Format: ST_NumGeometries (A: Geometry)
Since: v1.3.0
Example
SELECT ST_NumGeometries(ST_GeomFromWKT('LINESTRING (-29 -27, -30 -29.7, -45 -33)'))
Output:
1
ST_NumInteriorRing¶
Introduction: Returns number of interior rings of polygon geometries. It is an alias of ST_NumInteriorRings.
Format: ST_NumInteriorRing(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_NumInteriorRing(ST_GeomFromText('POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1))'))
Output:
1
ST_NumInteriorRings¶
Introduction: Returns number of interior rings of polygon geometries.
Format: ST_NumInteriorRings(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_NumInteriorRings(ST_GeomFromText('POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0), (1 1, 2 1, 2 2, 1 2, 1 1))'))
Output:
1
ST_NumPoints¶
Introduction: Returns number of points in a LineString.
Note
If any other geometry is provided as an argument, an IllegalArgumentException is thrown.
Example:
SELECT ST_NumPoints(ST_GeomFromWKT('MULTIPOINT ((0 0), (1 1), (0 1), (2 2))'))
Output: IllegalArgumentException: Unsupported geometry type: MultiPoint, only LineString geometry is supported.
Format: ST_NumPoints(geom: Geometry)
Since: v1.4.1
Example:
SELECT ST_NumPoints(ST_GeomFromText('LINESTRING(1 2, 1 3)'))
Output:
2
ST_PointN¶
Introduction: Return the Nth point in a single linestring or circular linestring in the geometry. Negative values are counted backwards from the end of the LineString, so that -1 is the last point. Returns NULL if there is no linestring in the geometry.
Format: ST_PointN(A: Geometry, B: Integer)
Since: v1.2.1
Examples:
SELECT ST_PointN(df.geometry, 2)
FROM df
Input: LINESTRING(0 0, 1 2, 2 4, 3 6), 2
Output: POINT (1 2)
Input: LINESTRING(0 0, 1 2, 2 4, 3 6), -2
Output: POINT (2 4)
Input: CIRCULARSTRING(1 1, 1 2, 2 4, 3 6, 1 2, 1 1), -1
Output: POINT (1 1)
ST_PointOnSurface¶
Introduction: Returns a POINT guaranteed to lie on the surface.
Format: ST_PointOnSurface(A: Geometry)
Since: v1.2.1
Examples:
SELECT ST_PointOnSurface(df.geometry)
FROM df
- Input:
POINT (0 5)
Output: POINT (0 5)
- Input:
LINESTRING(0 5, 0 10)
Output: POINT (0 5)
- Input:
POLYGON((0 0, 0 5, 5 5, 5 0, 0 0))
Output: POINT (2.5 2.5)
- Input:
LINESTRING(0 5 1, 0 0 1, 0 10 2)
Output: POINT Z(0 0 1)
ST_Points¶
Introduction: Returns a MultiPoint geometry consisting of all the coordinates of the input geometry. It preserves duplicate points as well as M and Z coordinates.
Format: ST_Points(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_AsText(ST_Points(ST_GeomFromEWKT('LINESTRING (2 4, 3 3, 4 2, 7 3)')));
Output:
MULTIPOINT ((2 4), (3 3), (4 2), (7,3))
ST_Polygon¶
Introduction: Function to create a polygon built from the given LineString and sets the spatial reference system from the srid
Format: ST_Polygon(geom: Geometry, srid: Integer)
Since: v1.5.0
Example:
SELECT ST_AsText( ST_Polygon(ST_GeomFromEWKT('LINESTRING(75 29 1, 77 29 2, 77 29 3, 75 29 1)'), 4326) );
Output:
POLYGON((75 29 1, 77 29 2, 77 29 3, 75 29 1))
ST_Polygonize¶
Introduction: Generates a GeometryCollection composed of polygons that are formed from the linework of an input GeometryCollection. When the input does not contain any linework that forms a polygon, the function will return an empty GeometryCollection.
Note
ST_Polygonize function assumes that the input geometries form a valid and simple closed linestring that can be turned into a polygon. If the input geometries are not noded or do not form such linestrings, the resulting GeometryCollection may be empty or may not contain the expected polygons.
Format: ST_Polygonize(geom: Geometry)
Since: v1.6.0
Example:
SELECT ST_AsText(ST_Polygonize(ST_GeomFromEWKT('GEOMETRYCOLLECTION (LINESTRING (2 0, 2 1, 2 2), LINESTRING (2 2, 2 3, 2 4), LINESTRING (0 2, 1 2, 2 2), LINESTRING (2 2, 3 2, 4 2), LINESTRING (0 2, 1 3, 2 4), LINESTRING (2 4, 3 3, 4 2))')));
Output:
GEOMETRYCOLLECTION (POLYGON ((0 2, 1 3, 2 4, 2 3, 2 2, 1 2, 0 2)), POLYGON ((2 2, 2 3, 2 4, 3 3, 4 2, 3 2, 2 2)))
ST_ReducePrecision¶
Introduction: Reduce the decimals places in the coordinates of the geometry to the given number of decimal places. The last decimal place will be rounded.
Format: ST_ReducePrecision (A: Geometry, B: Integer)
Since: v1.5.0
Example:
SELECT ST_ReducePrecision(ST_GeomFromWKT('Point(0.1234567890123456789 0.1234567890123456789)')
, 9)
The new coordinates will only have 9 decimal places.
Output:
POINT (0.123456789 0.123456789)
ST_Reverse¶
Introduction: Return the geometry with vertex order reversed
Format: ST_Reverse (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_Reverse(ST_GeomFromWKT('LINESTRING(0 0, 1 2, 2 4, 3 6)'))
Output:
LINESTRING (3 6, 2 4, 1 2, 0 0)
ST_RemovePoint¶
Introduction: Return Linestring with removed point at given index, position can be omitted and then last one will be removed.
Format:
ST_RemovePoint(geom: Geometry, position: Integer)
ST_RemovePoint(geom: Geometry)
Since: v1.3.0
Example:
SELECT ST_RemovePoint(ST_GeomFromText("LINESTRING(0 0, 1 1, 1 0)"), 1)
Output:
LINESTRING(0 0, 1 0)
ST_Rotate¶
Introduction: Rotates a geometry by a specified angle in radians counter-clockwise around a given origin point. The origin for rotation can be specified as either a POINT geometry or x and y coordinates. If the origin is not specified, the geometry is rotated around POINT(0 0).
Formats;
ST_Rotate (geometry: Geometry, angle: Double)
ST_Rotate (geometry: Geometry, angle: Double, originX: Double, originY: Double)
ST_Rotate (geometry: Geometry, angle: Double, pointOrigin: Geometry)
Since: v1.6.1
SQL Example:
SELECT ST_Rotate(ST_GeomFromEWKT('SRID=4326;POLYGON ((0 0, 1 0, 1 1, 0 0))'), 10, 0, 0)
Output:
SRID=4326;POLYGON ((0 0, -0.8390715290764524 -0.5440211108893698, -0.2950504181870827 -1.383092639965822, 0 0))
ST_RotateX¶
Introduction: Performs a counter-clockwise rotation of the specified geometry around the X-axis by the given angle measured in radians.
Format: ST_RotateX(geometry: Geometry, angle: Double)
Since: v1.6.1
SQL Example:
SELECT ST_RotateX(ST_GeomFromEWKT('SRID=4326;POLYGON ((0 0, 1 0, 1 1, 0 0))'), 10)
Output:
SRID=4326;POLYGON ((0 0, 1 0, 1 -0.8390715290764524, 0 0))
ST_S2CellIDs¶
Introduction: Cover the geometry with Google S2 Cells, return the corresponding cell IDs with the given level. The level indicates the size of cells. With a bigger level, the cells will be smaller, the coverage will be more accurate, but the result size will be exponentially increasing.
Format: ST_S2CellIDs(geom: Geometry, level: Integer)
Since: v1.4.0
Example:
SELECT ST_S2CellIDs(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'), 6)
Output:
[1159395429071192064, 1159958379024613376, 1160521328978034688, 1161084278931456000, 1170091478186196992, 1170654428139618304]
ST_S2ToGeom¶
Introduction: Returns an array of Polygons for the corresponding S2 cell IDs.
Hint
To convert a Polygon array to MultiPolygon, use ST_Collect. However, the result may be an invalid geometry. Apply ST_MakeValid to the ST_Collect output to ensure a valid MultiPolygon.
An alternative approach to consolidate a Polygon array into a Polygon/MultiPolygon, use the ST_Union function.
Format: ST_S2ToGeom(cellIds: Array[Long])
Since: v1.6.0
SQL Example:
SELECT ST_S2ToGeom(array(11540474045136890))
Output:
[POLYGON ((-36.609392788630245 -38.169532607255846, -36.609392706252954 -38.169532607255846, -36.609392706252954 -38.169532507473015, -36.609392788630245 -38.169532507473015, -36.609392788630245 -38.169532607255846))]
ST_SetPoint¶
Introduction: Replace Nth point of linestring with given point. Index is 0-based. Negative index are counted backwards, e.g., -1 is last point.
Format: ST_SetPoint (linestring: Geometry, index: Integer, point: Geometry)
Since: v1.3.0
Example:
SELECT ST_SetPoint(ST_GeomFromText('LINESTRING (0 0, 0 1, 1 1)'), 2, ST_GeomFromText('POINT (1 0)'))
Output:
LINESTRING (0 0, 0 1, 1 0)
ST_SetSRID¶
Introduction: Sets the spatial reference system identifier (SRID) of the geometry.
Format: ST_SetSRID (A: Geometry, srid: Integer)
Since: v1.3.0
Example:
SELECT ST_AsEWKT(ST_SetSRID(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'), 3021))
Output:
SRID=3021;POLYGON ((1 1, 8 1, 8 8, 1 8, 1 1))
ST_ShiftLongitude¶
Introduction: Modifies longitude coordinates in geometries, shifting values between -180..0 degrees to 180..360 degrees and vice versa. This is useful for normalizing data across the International Date Line and standardizing coordinate ranges for visualization and spheroidal calculations.
Note
This function is only applicable to geometries that use lon/lat coordinate systems.
Format: ST_ShiftLongitude (geom: geometry)
Since: v1.6.0
SQL example:
SELECT ST_ShiftLongitude(ST_GeomFromText('LINESTRING(177 10, 179 10, -179 10, -177 10)'))
Output:
LINESTRING(177 10, 179 10, 181 10, 183 10)
ST_SRID¶
Introduction: Return the spatial reference system identifier (SRID) of the geometry.
Format: ST_SRID (A: Geometry)
Since: v1.3.0
Example:
SELECT ST_SRID(ST_SetSRID(ST_GeomFromWKT('POLYGON((1 1, 8 1, 8 8, 1 8, 1 1))'), 3021))
Output:
3021
ST_SimplifyPolygonHull¶
Introduction: This function computes a topology-preserving simplified hull, either outer or inner, for a polygonal geometry input. An outer hull fully encloses the original geometry, while an inner hull lies entirely within. The result maintains the same structure as the input, including handling of MultiPolygons and holes, represented as a polygonal geometry formed from a subset of vertices.
Vertex reduction is governed by the vertexFactor parameter ranging from 0 to 1, with lower values yielding simpler outputs with fewer vertices and reduced concavity. For both hull types, a vertexFactor of 1.0 returns the original geometry. Specifically, for outer hulls, 0.0 computes the convex hull; for inner hulls, 0.0 produces a triangular geometry.
The simplification algorithm iteratively removes concave corners containing the least area until reaching the target vertex count. It preserves topology by preventing edge crossings, ensuring the output is a valid polygonal geometry in all cases.
Format:
ST_SimplifyPolygonHull(geom: Geometry, vertexFactor: Double, isOuter: Boolean = true)
ST_SimplifyPolygonHull(geom: Geometry, vertexFactor: Double)
Since: v1.6.1
SQL Example
SELECT ST_SimplifyPolygonHull(
ST_GeomFromText('POLYGON ((30 10, 40 40, 45 45, 50 30, 55 25, 60 50, 65 45, 70 30, 75 20, 80 25, 70 10, 30 10))'),
0.4
)
Output:
POLYGON ((30 10, 40 40, 45 45, 60 50, 65 45, 80 25, 70 10, 30 10))
SQL Example
SELECT ST_SimplifyPolygonHull(
ST_GeomFromText('POLYGON ((30 10, 40 40, 45 45, 50 30, 55 25, 60 50, 65 45, 70 30, 75 20, 80 25, 70 10, 30 10))'),
0.4, false
)
Output:
POLYGON ((30 10, 70 10, 60 50, 55 25, 30 10))
ST_SimplifyPreserveTopology¶
Introduction: Simplifies a geometry and ensures that the result is a valid geometry having the same dimension and number of components as the input, and with the components having the same topological relationship.
Since: v1.5.0
Format: ST_SimplifyPreserveTopology (A: Geometry, distanceTolerance: Double)
Example:
SELECT ST_SimplifyPreserveTopology(ST_GeomFromText('POLYGON((8 25, 28 22, 28 20, 15 11, 33 3, 56 30, 46 33,46 34, 47 44, 35 36, 45 33, 43 19, 29 21, 29 22,35 26, 24 39, 8 25))'), 10)
Output:
POLYGON ((8 25, 28 22, 15 11, 33 3, 56 30, 47 44, 35 36, 43 19, 24 39, 8 25))
ST_SimplifyVW¶
Introduction: This function simplifies the input geometry by applying the Visvalingam-Whyatt algorithm.
Note
The simplification may not preserve topology, potentially producing invalid geometries. Use ST_SimplifyPreserveTopology to retain valid topology after simplification.
Format: ST_SimplifyVW(geom: Geometry, tolerance: Double)
Since: v1.6.1
SQL Example
SELECT ST_SimplifyVW(ST_GeomFromWKT('POLYGON((8 25, 28 22, 28 20, 15 11, 33 3, 56 30, 46 33,46 34, 47 44, 35 36, 45 33, 43 19, 29 21, 29 22,35 26, 24 39, 8 25))'), 80)
Output:
POLYGON ((8 25, 28 22, 15 11, 33 3, 56 30, 47 44, 43 19, 24 39, 8 25))
ST_Snap¶
Introduction: Snaps the vertices and segments of the input geometry to reference geometry within the specified tolerance distance. The tolerance parameter controls the maximum snap distance.
If the minimum distance between the geometries exceeds the tolerance, the input geometry is returned unmodified. Adjusting the tolerance value allows tuning which vertices should snap to the reference and which remain untouched.
Since: v1.6.0
Format: ST_Snap(input: Geometry, reference: Geometry, tolerance: double)
Input geometry:
SQL Example:
SELECT
ST_Snap(poly, line, ST_Distance(poly, line) * 1.01) AS polySnapped FROM (
SELECT ST_GeomFromWKT('POLYGON ((236877.58 -6.61, 236878.29 -8.35, 236879.98 -8.33, 236879.72 -7.63, 236880.35 -6.62, 236877.58 -6.61), (236878.45 -7.01, 236878.43 -7.52, 236879.29 -7.50, 236878.63 -7.22, 236878.76 -6.89, 236878.45 -7.01))') as poly,
ST_GeomFromWKT('LINESTRING (236880.53 -8.22, 236881.15 -7.68, 236880.69 -6.81)') as line
)
Output:
POLYGON ((236877.58 -6.61, 236878.29 -8.35, 236879.98 -8.33, 236879.72 -7.63, 236880.69 -6.81, 236877.58 -6.61), (236878.45 -7.01, 236878.43 -7.52, 236879.29 -7.5, 236878.63 -7.22, 236878.76 -6.89, 236878.45 -7.01))
ST_StartPoint¶
Introduction: Returns first point of given linestring.
Format: ST_StartPoint(geom: Geometry)
Since: v1.5.0
Example:
SELECT ST_StartPoint(ST_GeomFromText('LINESTRING(100 150,50 60, 70 80, 160 170)'))
Output:
POINT(100 150)
ST_SubDivide¶
Introduction: Returns list of geometries divided based of given maximum number of vertices.
Format: ST_SubDivide(geom: Geometry, maxVertices: Integer)
Since: v1.5.0
Example:
SELECT ST_SubDivide(ST_GeomFromText("POLYGON((35 10, 45 45, 15 40, 10 20, 35 10), (20 30, 35 35, 30 20, 20 30))"), 5)
Output:
[
POLYGON((37.857142857142854 20, 35 10, 10 20, 37.857142857142854 20)),
POLYGON((15 20, 10 20, 15 40, 15 20)),
POLYGON((20 20, 15 20, 15 30, 20 30, 20 20)),
POLYGON((26.428571428571427 20, 20 20, 20 30, 26.4285714 23.5714285, 26.4285714 20)),
POLYGON((15 30, 15 40, 20 40, 20 30, 15 30)),
POLYGON((20 40, 26.4285714 40, 26.4285714 32.1428571, 20 30, 20 40)),
POLYGON((37.8571428 20, 30 20, 34.0476190 32.1428571, 37.8571428 32.1428571, 37.8571428 20)),
POLYGON((34.0476190 34.6825396, 26.4285714 32.1428571, 26.4285714 40, 34.0476190 40, 34.0476190 34.6825396)),
POLYGON((34.0476190 32.1428571, 35 35, 37.8571428 35, 37.8571428 32.1428571, 34.0476190 32.1428571)),
POLYGON((35 35, 34.0476190 34.6825396, 34.0476190 35, 35 35)),
POLYGON((34.0476190 35, 34.0476190 40, 37.8571428 40, 37.8571428 35, 34.0476190 35)),
POLYGON((30 20, 26.4285714 20, 26.4285714 23.5714285, 30 20)),
POLYGON((15 40, 37.8571428 43.8095238, 37.8571428 40, 15 40)),
POLYGON((45 45, 37.8571428 20, 37.8571428 43.8095238, 45 45))
]
Example:
SELECT ST_SubDivide(ST_GeomFromText("LINESTRING(0 0, 85 85, 100 100, 120 120, 21 21, 10 10, 5 5)"), 5)
Output:
[
LINESTRING(0 0, 5 5)
LINESTRING(5 5, 10 10)
LINESTRING(10 10, 21 21)
LINESTRING(21 21, 60 60)
LINESTRING(60 60, 85 85)
LINESTRING(85 85, 100 100)
LINESTRING(100 100, 120 120)
]
ST_SymDifference¶
Introduction: Return the symmetrical difference between geometry A and B (return parts of geometries which are in either of the sets, but not in their intersection)
Format: ST_SymDifference (A: Geometry, B: Geometry)
Since: v1.5.0
Example:
SELECT ST_SymDifference(ST_GeomFromWKT('POLYGON ((-3 -3, 3 -3, 3 3, -3 3, -3 -3))'), ST_GeomFromWKT('POLYGON ((-2 -3, 4 -3, 4 3, -2 3, -2 -3))'))
Output:
MULTIPOLYGON (((-2 -3, -3 -3, -3 3, -2 3, -2 -3)), ((3 -3, 3 3, 4 3, 4 -3, 3 -3)))
ST_Transform¶
Introduction:
Transform the Spatial Reference System / Coordinate Reference System of A, from SourceCRS to TargetCRS. For SourceCRS and TargetCRS, WKT format is also available since v1.3.1.
Lon/Lat Order in the input geometry
If the input geometry is in lat/lon order, it might throw an error such as too close to pole, latitude or longitude exceeded limits, or give unexpected results.
You need to make sure that the input geometry is in lon/lat order. If the input geometry is in lat/lon order, you can use ST_FlipCoordinates to swap X and Y.
Lon/Lat Order in the source and target CRS
Sedona will force the source and target CRS to be in lon/lat order. If the source CRS or target CRS is in lat/lon order, it will be swapped to lon/lat order.
CRS code
The CRS code is the code of the CRS in the official EPSG database (https://epsg.org/) in the format of EPSG:XXXX. A community tool EPSG.io can help you quick identify a CRS code. For example, the code of WGS84 is EPSG:4326.
WKT format
You can also use OGC WKT v1 format to specify the source CRS and target CRS. An example OGC WKT v1 CRS of EPGS:3857 is as follows:
PROJCS["WGS 84 / Pseudo-Mercator",
GEOGCS["WGS 84",
DATUM["WGS_1984",
SPHEROID["WGS 84",6378137,298.257223563,
AUTHORITY["EPSG","7030"]],
AUTHORITY["EPSG","6326"]],
PRIMEM["Greenwich",0,
AUTHORITY["EPSG","8901"]],
UNIT["degree",0.0174532925199433,
AUTHORITY["EPSG","9122"]],
AUTHORITY["EPSG","4326"]],
PROJECTION["Mercator_1SP"],
PARAMETER["central_meridian",0],
PARAMETER["scale_factor",1],
PARAMETER["false_easting",0],
PARAMETER["false_northing",0],
UNIT["metre",1,
AUTHORITY["EPSG","9001"]],
AXIS["Easting",EAST],
AXIS["Northing",NORTH],
EXTENSION["PROJ4","+proj=merc +a=6378137 +b=6378137 +lat_ts=0 +lon_0=0 +x_0=0 +y_0=0 +k=1 +units=m +nadgrids=@null +wktext +no_defs"],
AUTHORITY["EPSG","3857"]]
Note
By default, this function uses lon/lat order since v1.5.0. Before, it used lat/lon order.
Note
By default, ST_Transform follows the lenient mode which tries to fix issues by itself. You can append a boolean value at the end to enable the strict mode. In strict mode, ST_Transform will throw an error if it finds any issue.
Format:
ST_Transform (A: Geometry, SourceCRS: String, TargetCRS: String, [Optional] lenientMode: Boolean)
Since: v1.2.0
Example:
SELECT ST_AsText(ST_Transform(ST_GeomFromText('POLYGON((170 50,170 72,-130 72,-130 50,170 50))'),'EPSG:4326', 'EPSG:32649'))
SELECT ST_AsText(ST_Transform(ST_GeomFromText('POLYGON((170 50,170 72,-130 72,-130 50,170 50))'),'EPSG:4326', 'EPSG:32649', false))
Output:
POLYGON ((8766047.980342899 17809098.336766362, 5122546.516721856 18580261.912528664, 3240775.0740796793 -13688660.50985159, 4556241.924514083 -12463044.21488129, 8766047.980342899 17809098.336766362))
ST_Translate¶
Introduction: Returns the input geometry with its X, Y and Z coordinates (if present in the geometry) translated by deltaX, deltaY and deltaZ (if specified)
If the geometry is 2D, and a deltaZ parameter is specified, no change is done to the Z coordinate of the geometry and the resultant geometry is also 2D.
If the geometry is empty, no change is done to it.
If the given geometry contains sub-geometries (GEOMETRY COLLECTION, MULTI POLYGON/LINE/POINT), all underlying geometries are individually translated.
Format:
ST_Translate(geometry: Geometry, deltaX: Double, deltaY: Double, deltaZ: Double)
Since: v1.4.1
Example:
SELECT ST_Translate(ST_GeomFromText('GEOMETRYCOLLECTION(MULTIPOLYGON(((3 2,3 3,4 3,4 2,3 2)),((3 4,5 6,5 7,3 4))), POINT(1 1 1), LINESTRING EMPTY)'), 2, 2, 3)
Output:
GEOMETRYCOLLECTION (MULTIPOLYGON (((5 4, 5 5, 6 5, 6 4, 5 4)), ((5 6, 7 8, 7 9, 5 6))), POINT (3 3), LINESTRING EMPTY)
Example:
SELECT ST_Translate(ST_GeomFromText('POINT(-71.01 42.37)'),1,2)
Output:
POINT (-70.01 44.37)
ST_TriangulatePolygon¶
Introduction: Generates the constrained Delaunay triangulation for the input Polygon. The constrained Delaunay triangulation is a set of triangles created from the Polygon's vertices that covers the Polygon area precisely, while maximizing the combined interior angles across all triangles compared to other possible triangulations. This produces the highest quality triangulation representation of the Polygon geometry. The function returns a GeometryCollection of Polygon geometries comprising this optimized constrained Delaunay triangulation. Polygons with holes and MultiPolygon types are supported. For any other geometry type provided, such as Point, LineString, etc., an empty GeometryCollection will be returned.
Format: ST_TriangulatePolygon(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_TriangulatePolygon(
ST_GeomFromWKT('POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0), (5 5, 5 8, 8 8, 8 5, 5 5))')
)
Output:
GEOMETRYCOLLECTION (POLYGON ((0 0, 0 10, 5 5, 0 0)), POLYGON ((5 8, 5 5, 0 10, 5 8)), POLYGON ((10 0, 0 0, 5 5, 10 0)), POLYGON ((10 10, 5 8, 0 10, 10 10)), POLYGON ((10 0, 5 5, 8 5, 10 0)), POLYGON ((5 8, 10 10, 8 8, 5 8)), POLYGON ((10 10, 10 0, 8 5, 10 10)), POLYGON ((8 5, 8 8, 10 10, 8 5)))
ST_UnaryUnion¶
Introduction: This variant of ST_Union operates on a single geometry input. The input geometry can be a simple Geometry type, a MultiGeometry, or a GeometryCollection. The function calculates the geometric union across all components and elements within the provided geometry object.
Format: ST_UnaryUnion(geometry: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_UnaryUnion(ST_GeomFromWKT('MULTIPOLYGON(((0 10,0 30,20 30,20 10,0 10)),((10 0,10 20,30 20,30 0,10 0)))'))
Output:
POLYGON ((10 0, 10 10, 0 10, 0 30, 20 30, 20 20, 30 20, 30 0, 10 0))
ST_Union¶
Introduction:
Variant 1: Return the union of geometry A and B.
Variant 2: This function accepts an array of Geometry objects and returns the geometric union of all geometries in the input array. If the polygons within the input array do not share common boundaries, the ST_Union result will be a MultiPolygon geometry.
Format:
ST_Union (A: Geometry, B: Geometry)
ST_Union (geoms: Array(Geometry))
Since: v1.6.0
SQL Example
SELECT ST_Union(ST_GeomFromWKT('POLYGON ((-3 -3, 3 -3, 3 3, -3 3, -3 -3))'), ST_GeomFromWKT('POLYGON ((1 -2, 5 0, 1 2, 1 -2))'))
Output:
POLYGON ((3 -1, 3 -3, -3 -3, -3 3, 3 3, 3 1, 5 0, 3 -1))
SQL Example
SELECT ST_Union(
Array(
ST_GeomFromWKT('POLYGON ((-3 -3, 3 -3, 3 3, -3 3, -3 -3))'),
ST_GeomFromWKT('POLYGON ((-2 1, 2 1, 2 4, -2 4, -2 1))')
)
)
Output:
POLYGON ((2 3, 3 3, 3 -3, -3 -3, -3 3, -2 3, -2 4, 2 4, 2 3))
ST_VoronoiPolygons¶
Introduction: Returns a two-dimensional Voronoi diagram from the vertices of the supplied geometry. The result is a GeometryCollection of Polygons that covers an envelope larger than the extent of the input vertices. Returns null if input geometry is null. Returns an empty geometry collection if the input geometry contains only one vertex. Returns an empty geometry collection if the extend_to envelope has zero area.
Format: ST_VoronoiPolygons(g1: Geometry, tolerance: Double, extend_to: Geometry)
Optional parameters:
tolerance : The distance within which vertices will be considered equivalent. Robustness of the algorithm can be improved by supplying a nonzero tolerance distance. (default = 0.0)
extend_to : If a geometry is supplied as the "extend_to" parameter, the diagram will be extended to cover the envelope of the "extend_to" geometry, unless that envelope is smaller than the default envelope (default = NULL. By default, we extend the bounding box of the diagram by the max between bounding box's height and bounding box's width).
Since: v1.5.0
Example:
SELECT st_astext(ST_VoronoiPolygons(ST_GeomFromText('MULTIPOINT ((0 0), (1 1))')));
Output:
GEOMETRYCOLLECTION(POLYGON((-1 2,2 -1,-1 -1,-1 2)),POLYGON((-1 2,2 2,2 -1,-1 2)))
ST_X¶
Introduction: Returns X Coordinate of given Point, null otherwise.
Format: ST_X(pointA: Point)
Since: v1.3.0
Example:
SELECT ST_X(ST_POINT(0.0 25.0))
Output:
0.0
ST_XMax¶
Introduction: Returns the maximum X coordinate of a geometry
Format: ST_XMax (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_XMax(ST_GeomFromText('POLYGON ((-1 -11, 0 10, 1 11, 2 12, -1 -11))'))
Output:
2
ST_XMin¶
Introduction: Returns the minimum X coordinate of a geometry
Format: ST_XMin (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_XMin(ST_GeomFromText('POLYGON ((-1 -11, 0 10, 1 11, 2 12, -1 -11))'))
Output:
-1
ST_Y¶
Introduction: Returns Y Coordinate of given Point, null otherwise.
Format: ST_Y(pointA: Point)
Since: v1.3.0
Example:
SELECT ST_Y(ST_POINT(0.0 25.0))
Output:
25.0
ST_YMax¶
Introduction: Return the minimum Y coordinate of A
Format: ST_YMax (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_YMax(ST_GeomFromText('POLYGON((0 0 1, 1 1 1, 1 2 1, 1 1 1, 0 0 1))'))
Output :
2
ST_YMin¶
Introduction: Return the minimum Y coordinate of A
Format: ST_Y_Min (A: Geometry)
Since: v1.2.1
Example:
SELECT ST_YMin(ST_GeomFromText('POLYGON((0 0 1, 1 1 1, 1 2 1, 1 1 1, 0 0 1))'))
Output:
0
ST_Z¶
Introduction: Returns Z Coordinate of given Point, null otherwise.
Format: ST_Z(pointA: Point)
Since: v1.3.0
Example:
SELECT ST_Z(ST_POINT(0.0 25.0 11.0))
Output:
11.0
ST_ZMax¶
Introduction: Returns Z maxima of the given geometry or null if there is no Z coordinate.
Format: ST_ZMax(geom: Geometry)
Since: v1.3.1
Example:
SELECT ST_ZMax(ST_GeomFromText('POLYGON((0 0 1, 1 1 1, 1 2 1, 1 1 1, 0 0 1))'))
Output:
1.0
ST_ZMin¶
Introduction: Returns Z minima of the given geometry or null if there is no Z coordinate.
Format: ST_ZMin(geom: Geometry)
Since: v1.3.1
Example:
SELECT ST_ZMin(ST_GeomFromText('LINESTRING(1 3 4, 5 6 7)'))
Output:
4.0
ST_Zmflag¶
Introduction: Returns a code indicating the Z and M coordinate dimensions present in the input geometry.
Values are: 0 = 2D, 1 = 3D-M, 2 = 3D-Z, 3 = 4D.
Format: ST_Zmflag(geom: Geometry)
Since: v1.6.1
SQL Example
SELECT ST_Zmflag(
ST_GeomFromWKT('LINESTRING Z(1 2 3, 4 5 6)')
)
Output:
2
SQL Example
SELECT ST_Zmflag(
ST_GeomFromWKT('POINT ZM(1 2 3 4)')
)
Output:
3