# Spatial Functions The following spatial functions are available in Neptune openCypher for working with geometry data types: + [ST\$1Point](access-graph-opencypher-22-spatial-functions-st-point.md) + [ST\$1GeomFromText](access-graph-opencypher-22-spatial-functions-st-geomfromtext.md) + [ST\$1AsText](access-graph-opencypher-22-spatial-functions-st-astext.md) + [ST\$1GeometryType](access-graph-opencypher-22-spatial-functions-st-geometrytype.md) + [ST\$1Equals](access-graph-opencypher-22-spatial-functions-st-equals.md) + [ST\$1Contains](access-graph-opencypher-22-spatial-functions-st-contains.md) + [ST\$1Intersects](access-graph-opencypher-22-spatial-functions-st-intersect.md) + [ST\$1Distance](access-graph-opencypher-22-spatial-functions-st-distance.md) + [ST\$1DistanceSpheroid](access-graph-opencypher-22-spatial-functions-st-distancespheroid.md) + [ST\$1Envelope](access-graph-opencypher-22-spatial-functions-st-envelope.md) + [ST\$1Buffer](access-graph-opencypher-22-spatial-functions-st-buffer.md) # ST\$1Point ST\$1Point returns a point from the input coordinate values. **Syntax** ``` ST_Point(x, y, z) ``` **Arguments** + `x` - A value of data type DOUBLE PRECISION that represents a first coordinate. + `y` - A value of data type DOUBLE PRECISION that represents a second coordinate. + `z` - (optional) **Coordinate order** When working with geographic coordinates, the first argument (`x`) represents **longitude** and the second argument (`y`) represents **latitude**. This follows the standard coordinate order used in spatial databases and the ISO 19125 standard. ``` // Correct: longitude first, latitude second ST_Point(-84.4281, 33.6367) // Atlanta airport // Incorrect: latitude first, longitude second ST_Point(33.6367, -84.4281) // This will return NaN in distance calculations ``` **Valid coordinate ranges** For geographic data, ensure coordinates fall within valid ranges: + Longitude (`x`): -180 to 180 + Latitude (`y`): -90 to 90 Coordinates outside these ranges will return `NaN` (Not a Number) when used with distance calculation functions like `ST_DistanceSpheroid`. **Return type** GEOMETRY of subtype POINT If x or y is null, then null is returned. **Examples** The following constructs a point geometry from the input coordinates. ``` RETURN ST_Point(5.0, 7.0); POINT(5 7) ``` # ST\$1GeomFromText ST\$1GeomFromText constructs a geometry object from a well-known text (WKT) representation of an input geometry. **Syntax** ``` ST_GeomFromText(wkt_string) ``` **Arguments** + `wkt_string` - A value of data type STRING that is a WKT representation of a geometry. **Return type** GEOMETRY If wkt\$1string is null, then null is returned. If wkt\$1string is not valid, then a BadRequestException is returned. **Examples** ``` RETURN ST_GeomFromText('POLYGON((0 0,0 1,1 1,1 0,0 0))') POLYGON((0 0,0 1,1 1,1 0,0 0)) ``` # ST\$1AsText ST\$1AsText returns the well-known text (WKT) representation of an input geometry. **Syntax** ``` ST_AsText(geo) ``` **Arguments** + `geo` - A value of data type GEOMETRY, or an expression that evaluates to a GEOMETRY. **Return type** STRING If geo is null, then null is returned. If the input parameter is not a Geometry, then a BadRequestException is returned. If the result is larger than a 64-KB STRING, then an error is returned. **Examples** ``` RETURN ST_AsText(ST_GeomFromText('POLYGON((0 0,0 1,1 1,1 0,0 0))')) POLYGON((0 0,0 1,1 1,1 0,0 0)) ``` # ST\$1GeometryType ST\$1GeometryType returns the type of the geometry as a string. **Syntax** ``` ST_GeometryType(geom) ``` **Arguments** + `geom` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. **Return type** STRING If geom is null, then null is returned. If the input parameter is not a Geometry, then a BadRequestException is returned. **Examples** ``` RETURN ST_GeometryType(ST_GeomFromText('LINESTRING(77.29 29.07,77.42 29.26,77.27 29.31,77.29 29.07)')); ST_LineString ``` # ST\$1Equals ST\$1Equals returns true if the 2D projections of the input geometries are topologically equal. Geometries are considered topologically equal if they have equal point sets. In topologically equal geometries, the order of vertices may differ while maintaining this equality. **Syntax** ``` ST_Equals(geom1, geom2) ``` **Arguments** + `geom1` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. + `geom2` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. This value is compared with geom1 to determine if it is equal to geom1. **Return type** BOOLEAN If geom1 or geom2 is null, then null is returned. If geom1 or geom2 are not Geometries, then a BadRequestException is returned. **Examples** ``` RETURN ST_Equals( ST_GeomFromText('POLYGON ((0 2,1 1,0 -1,0 2))'), ST_GeomFromText('POLYGON((-1 3,2 1,0 -3,-1 3))')); false ``` The following checks if the two linestrings are geometrically equal. ``` RETURN ST_Equals( ST_GeomFromText('LINESTRING (1 0, 10 0)'), ST_GeomFromText('LINESTRING(1 0,5 0,10 0)')); true ``` # ST\$1Contains ST\$1Contains returns true if the 2D projection of the first input geometry contains the 2D projection of the second input geometry. Geometry A contains geometry B if every point in B is a point in A, and their interiors have nonempty intersection. ST\$1Contains(A, B) is equivalent to ST\$1Within(B, A). **Syntax** ``` ST_Contains(geom1, geom2) ``` **Arguments** + `geom1` - A value of type GEOMETRY or an expression that evaluates to a GEOMETRY type. + `geom2` - A value of type GEOMETRY or an expression that evaluates to a GEOMETRY type. This value is compared with geom1 to determine if it is contained within geom1. **Return type** BOOLEAN If geom1 or geom2 is null, then null is returned. If the input parameter is not a Geometry, then a BadRequestException is returned. **Examples** ``` RETURN ST_Contains( ST_GeomFromText('POLYGON((0 2,1 1,0 -1,0 2))'), ST_GeomFromText('POLYGON((-1 3,2 1,0 -3,-1 3))')); false ``` # ST\$1Intersects ST\$1Intersects returns true if the 2D projections of the two input geometries have at least one point in common. **Syntax** ``` ST_Intersects(geom1, geom2) ``` **Arguments** + `geom1` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. + `geom2` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. **Return type** BOOLEAN If geom1 or geom2 is null, then null is returned. If the input parameter is not a Geometry, then a BadRequestException is returned. **Examples** ``` RETURN ST_Intersects( ST_GeomFromText('POLYGON((0 0,10 0,10 10,0 10,0 0),(2 2,2 5,5 5,5 2,2 2))'), ST_GeomFromText('MULTIPOINT((4 4),(6 6))')); true ``` # ST\$1Distance For input geometries, ST\$1Distance returns the minimum Euclidean distance between the 2D projections of the two input geometry values. **Syntax** ``` ST_Distance(geo1, geo2) ``` **Arguments** + `geo1` - A value of data type GEOMETRY, or an expression that evaluates to a GEOMETRY type. + `geo2` - A value of data type GEOMETRY, or an expression that evaluates to a GEOMETRY. **Return type** DOUBLE PRECISION in the same units as the input geometries. If geo1 or geo2 is null, then null is returned. If the input parameter is not a Geometry, then a BadRequestException is returned. **Examples** ``` RETURN ST_Distance( ST_GeomFromText('POLYGON((0 2,1 1,0 -1,0 2))'), ST_GeomFromText('POLYGON((-1 -3,-2 -1,0 -3,-1 -3))')); 1.4142135623731 ``` # ST\$1DistanceSpheroid Returns the minimum distance in meters between two lon/lat geometries. The spheroid is WGS84/SRID 4326. **Syntax** ``` ST_DistanceSpheroid(geom1, geom2); ``` **Arguments** + `geom1` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. + `geom2` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. **Return type** FLOAT If geom is null, then null is returned. **Examples** ``` RETURN ST_DistanceSpheroid( ST_GeomFromText('POINT(-110 42)'), ST_GeomFromText('POINT(-118 38)')) 814278.77 ``` # ST\$1Envelope ST\$1Envelope returns the minimum bounding box of the input geometry, as follows: + If the input geometry is empty, the returned geometry will be POINT EMPTY. + If the minimum bounding box of the input geometry degenerates to a point, the returned geometry is a point. + If none of the preceding is true, the function returns a counter-clockwise-oriented polygon whose vertices are the corners of the minimum bounding box. For all nonempty input, the function operates on the 2D projection of the input geometry. **Syntax** ``` ST_Envelope(geom) ``` **Arguments** + `geom` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. **Return type** GEOMETRY If geom is null, then null is returned. **Examples** ``` RETURN ST_Envelope(ST_GeomFromText("POLYGON ((2 1, 4 3, 6 1, 5 5, 3 4, 2 1))")) POLYGON ((2 1, 6 1, 6 5, 2 5, 2 1)) ``` # ST\$1Buffer ST\$1Buffer returns 2D geometry that represents all points whose distance from the input geometry projected on the xy-Cartesian plane is less than or equal to the input distance. **Syntax** ``` ST_Buffer(geom, distance, number_of_segments_per_quarter_circle) ``` **Arguments** + `geom` - A value of data type GEOMETRY or an expression that evaluates to a GEOMETRY type. + `distance` - A value of data type DOUBLE PRECISION that represents distance (or radius) of the buffer. + `number_of_segments_per_quarter_circle` - A value of data type INTEGER (should be larger or equal to 0). This value determines the number of points to approximate a quarter circle around each vertex of the input geometry. Negative values default to zero. The default is 8. **Return type** GEOMETRY The ST\$1Buffer function returns two-dimensional (2D) geometry in the xy-Cartesian plane. **Examples** ``` RETURN ST_Buffer(ST_GeomFromText('LINESTRING (1 2,5 2,5 8)'), 2, 4); POLYGON ((3 4, 3 8, 3.1522409349774265 8.76536686473018, 3.585786437626905 9.414213562373096, 4.234633135269821 9.847759065022574, 5 10, 5.765366864730179 9.847759065022574, 6.414213562373095 9.414213562373096, 6.847759065022574 8.76536686473018, 7 8, 7 2, 6.847759065022574 1.2346331352698203, 6.414213562373095 0.5857864376269051, 5.765366864730179 0.1522409349774265, 5 0, 1 0, 0.2346331352698193 0.152240934977427, -0.4142135623730954 0.5857864376269051, -0.8477590650225737 1.2346331352698208, -1 2.0000000000000004, -0.8477590650225735 2.7653668647301797, -0.4142135623730949 3.414213562373095, 0.2346331352698206 3.8477590650225735, 1 4, 3 4)) ``` The following returns the buffer of the input point geometry which approximates a circle. Because the command specifies 3 as the number of segments per quarter circle, the function uses three segments to approximate the quarter circle. ``` RETURN ST_Buffer(ST_GeomFromText('POINT (1 1)'), 1.0, 8)); POLYGON ((2 1, 1.9807852804032304 0.8049096779838718, 1.9238795325112867 0.6173165676349102, 1.8314696123025453 0.4444297669803978, 1.7071067811865475 0.2928932188134525, 1.5555702330196022 0.1685303876974548, 1.3826834323650898 0.0761204674887133, 1.1950903220161284 0.0192147195967696, 1 0, 0.8049096779838718 0.0192147195967696, 0.6173165676349103 0.0761204674887133, 0.444429766980398 0.1685303876974545, 0.2928932188134525 0.2928932188134524, 0.1685303876974546 0.4444297669803978, 0.0761204674887133 0.6173165676349102, 0.0192147195967696 0.8049096779838714, 0 0.9999999999999999, 0.0192147195967696 1.1950903220161284, 0.0761204674887132 1.3826834323650896, 0.1685303876974545 1.555570233019602, 0.2928932188134523 1.7071067811865475, 0.4444297669803978 1.8314696123025453, 0.6173165676349097 1.9238795325112865, 0.8049096779838714 1.9807852804032304, 0.9999999999999998 2, 1.1950903220161284 1.9807852804032304, 1.38268343236509 1.9238795325112865, 1.5555702330196017 1.8314696123025453, 1.7071067811865475 1.7071067811865477, 1.8314696123025453 1.5555702330196022, 1.9238795325112865 1.3826834323650905, 1.9807852804032304 1.1950903220161286, 2 1)) ```