PostGIS geographic function

5.3 Geometry
ST_Collect — Create a from a set of geometry GeometryCollection or Multi * The geometric .
ST_LineFromMultiPoint — from MultiPoint Geometry creation LineString.
ST_MakeEnvelope — Create a rectangle from the minimum and maximum coordinates Polygon.
ST_MakeLine — from Point,MultiPoint or LineString Geometry creates a string .
ST_MakePoint — establish 2D,3DZ or 4D spot .
ST_MakePointM — from X,Y and M Value to create a point .
ST_MakePolygon — Create polygons from an optional list of shells and holes .
ST_Point — Create a with the given coordinate values Point. ST_MakePoint Another name for .
ST_Polygon — From has a specified SRID Of LineString Create polygons .
ST_TileEnvelope — Use XYZ Collage system in Web Mercator（SRID：3857） Create a rectangular polygon .
ST_HexagonGrid — Returns a set of hexagon and cell indexes that completely cover the range of geometric parameters .
ST_SquareGrid — Returns a set of grid squares and cell indexes that completely cover the range of geometric parameters .
ST_Hexagon — Use the edge size and pixel coordinates provided in the hexagonal grid space , Returns a single hexagon .
ST_Square — Use the edge size and pixel coordinates provided in the hexagonal grid space , Returns a single square .

5.4 Geometric access
GeometryType — Returns the type of geometry as text .
ST_Boundary — Returns the boundary of the geometry .
ST_CoordDim — Returns the coordinate dimensions of geometry .
ST_Dimension — Returns the topological dimension of the geometry .
ST_Dump — Returns a set of... For geometry components geometry_dump That's ok .
ST_DumpPoints — Returns a set of points in geometry geometry_dump That's ok .
ST_DumpRings — Returns a set of outer and inner rings of a polygon geometry_dump That's ok .
ST_EndPoint — return LineString or CircularLineString The last point .
ST_Envelope — Returns the geometry that represents the geometry bounding box .
ST_BoundingDiagonal — Returns the diagonal of the geometric bounding box .
ST_ExteriorRing — Back on behalf of Polygon The outer ring of LineString.
ST_GeometryN — Returns the first... Of a geometric set N Geometric elements .
ST_GeometryType — Returns geometric as text SQL-MM type .
ST_HasArc — Test whether the geometry contains arcs
ST_InteriorRingN — Returns the second dimension of the polygon N An inner ring （ hole ）.
ST_IsPolygonCCW — Test whether the polygon has an outer ring positioned counterclockwise and an inner ring positioned clockwise .
ST_IsPolygonCW — Test whether the polygon has a clockwise outer ring and a counterclockwise inner ring .
ST_IsClosed — test LineStrings Whether the start point and the end point of the coincide . about PolyhedralSurface test , Is it closed （ Volume ）.
ST_IsCollection — Test if geometry is a geometry set type .
ST_IsEmpty — Test whether the geometry is empty .
ST_IsRing — test LineString Whether it is closed and simple .
ST_IsSimple — Test whether the geometry has no self intersecting or self tangent points .
ST_M — Return point M coordinate .
ST_MemSize — Returns the amount of memory space occupied by geometry .
ST_NDims — Returns the coordinate dimensions of geometry .
ST_NPoints — Returns a point in geometry （ The vertices ） Count .
ST_NRings — Returns the number of rings in polygon geometry .
ST_NumGeometries — Returns the number of elements in a geometric set .
ST_NumInteriorRings — Returns the number of inner rings of a polygon （ hole ）.
ST_NumInteriorRing — Returns the number of inner rings of a polygon （ hole ）. ST_NumInteriorRings Of Aias
ST_NumPatches — Returns the number of faces on a polyhedral surface . For non polyhedral Geometry , Will return null.
ST_NumPoints — return LineString or CircularString Points in .
ST_PatchN — Returns the first... Of a polyhedral surface N Geometry （ Noodles ）.
ST_PointN — Returns the first... In the geometry LineString Or round LineString No N A little bit .
ST_Points — Returns a that contains all the coordinates of the geometry MultiPoint.
ST_StartPoint — return LineString The first point of .
ST_Summary — Returns a text summary of the geometry content .
ST_X — Return point X coordinate .
ST_Y — Return point Y coordinate .
ST_Z — Return point Z coordinate .
ST_Zmflag — Returns... Indicating geometry ZM Code of coordinate dimension .

5.5 Geometry editing
These functions change the type 、 Structure or vertex to create modified geometry .
ST_AddPoint— Add points to LineString.
ST_CollectionExtract — Given （ many ） The geometric , Returns a that consists only of elements of the specified type （ many ） The geometric .
ST_CollectionHomogenize — Given a geometric set , Return the “ The most simple ” Representation form .
ST_CurveToLine — Convert geometry containing curves to linear geometry .
ST_FlipCoordinates — return X and Y A geometric version of the axis that has been flipped .
ST_Force2D — Force geometry to “ Two dimensional pattern ”.
ST_Force3D — Force geometry to XYZ Pattern . This is a ST_Force3DZ Another name for .
ST_Force3DZ — Force geometry to XYZ Pattern .
ST_Force3DM — Force geometry to XYM Pattern .
ST_Force4D — Force geometry to XYZM Pattern .
ST_ForcePolygonCCW — Rotate all outer rings counterclockwise , Rotate all inner rings clockwise .
ST_ForceCollection — Convert geometry to GEOMETRYCOLLECTION.
ST_ForcePolygonCW — Orient all outer rings clockwise , Orient all inner rings counterclockwise .
ST_ForceSFS — Force geometry to use only SFS 1.1 Geometric type .
ST_ForceRHR — Forces the orientation of vertices in a polygon to follow the right-hand rule .
ST_ForceCurve — Convert geometry to its bend type （ If applicable ）.
ST_LineMerge — Return by placing MULTILINESTRING Sewn together to form （ A group of ）LineString.
ST_LineToCurve — Convert linear geometry to curved geometry .
ST_Multi — Return the geometry to MULTI * The geometric .
ST_Normalize — Returns the geometry in canonical form .
ST_QuantizeCoordinates — Set the least significant bit of the coordinate to zero
ST_RemovePoint — Remove points from string .
ST_RemoveRepeatedPoints — Returns the version of the given geometry , The duplicate points are deleted .
ST_Reverse — Returns geometry with opposite vertex order .
ST_Segmentize — Return to the modified geometry / Geography , The length of its segment does not exceed the given distance .
ST_SetPoint — Replace the points of the string with the given points .
ST_ShiftLongitude — stay -180…180 and 0…360 The geometry of moving geographical coordinates between .
ST_WrapX — Wrap geometry around X value .
ST_SnapToGrid — Snap all points of the input geometry to a regular mesh .
ST_Snap — Align the segments and vertices of the input geometry with the vertices of the reference geometry .
ST_SwapOrdinates — Returns the version of a given geometry that exchanges a given ordinate value .

5.6 Geometric verification
These functions are based on OGC SFS The standard test geometry is valid . They also provide information about the nature and location of the disability . There is also a function to create a valid geometry from an invalid Geometry .
ST_IsValid — Test whether the geometry is 2D The format in is correct .
ST_IsValidDetail— return valid_detail That's ok , This line indicates whether the geometry is valid , If not , Explain the reason and location .
ST_IsValidReason — Returns text explaining why the geometry is valid or invalid .
ST_MakeValid — Try to make invalid geometry valid without losing vertices .

5.7 Spatial reference system functions
These functions work with geometric spatial reference systems .
ST_SetSRID — Put the... On the geometry SRID Set to a specific integer value .
ST_SRID — Returns the... Defined in the spatial index table ST_Geometry Spatial reference identifier of .
ST_Transform — Returns a new geometry , Its coordinates have been converted to other spatial reference systems .

5.8 Geometric input
These functions create geometry objects from various text or binary formats .

5.8.1. Well-Known Text (WKT)
ST_BdPolyFromText — Construct a polygon given a closed string as an arbitrary set of multi line well-known text representations .
ST_BdMPolyFromText — Construct a polygon , Given an arbitrary set of closed strings , As a multi string text representation, the well-known text representation .
ST_GeogFromText — Represent or extend from known text （WKT） Returns the specified geographic value .
ST_GeographyFromText — Represent or extend from known text （WKT） Returns the specified geographic value .
ST_GeomCollFromText — Using the given SRID From the collection WKT Generate assembly Geometry . If not given SRID, The default is 0.
ST_GeomFromEWKT — From the extended known text representation （EWKT） Returns the specified ST_Geometry.
ST_GeometryFromText — From known textual representations （WKT） Returns the specified ST_Geometry. This is a ST_GeomFromText Another name for
ST_GeomFromText — From known textual representations （WKT） Returns the specified ST_Geometry.
ST_LineFromText — Using the given SRID from WKT Represents the generated geometry . If not given SRID, The default is 0.
ST_MLineFromText — from WKT Means to return the specified stu MultiLineString value .
ST_MPointFromText — Using the given SRID from WKT Generate Geometry . If not given SRID, The default is 0.
ST_MPolyFromText — Using the given SRID from WKT Generate polygonal Geometry . If not given SRID, The default is 0.
ST_PointFromText — Using the given SRID from WKT Generate point geometry . If not given SRID, The default is unknown .
ST_PolygonFromText — Using the given SRID from WKT Generate Geometry . If not given SRID, The default is 0.
ST_WKTToSQL — From known textual representations （WKT） Returns the specified ST_Geometry. This is a ST_GeomFromText Another name for

5.8.2. Well-Known Binary (WKB)
ST_GeogFromWKB — From known binary geometric representations （WKB） Or extended known binary （EWKB） Create a geographic instance .
ST_GeomFromEWKB — From the extended known binary notation （EWKB） Returns the specified ST\ Geometric value .
ST_GeomFromWKB — Represent from known binary geometry （WKB） And optional SRID Create geometry instances .
ST_LineFromWKB — Using the given SRID from WKB Generate a LINESTRING
ST_LinestringFromWKB — Using the given SRID from WKB Generate Geometry .
ST_PointFromWKB — Using the given SRID from WKB Generate Geometry
ST_WKBToSQL — From known binary notation （WKB） Returns the specified ST_Geometry value . This is not necessary srid Of ST_GeomFromWKB Another name for

5.8.3. Other Formats
ST_Box2dFromGeoHash — from GeoHash String returns BOX2D.
ST_GeomFromGeoHash — from GeoHash String returns Geometry .
ST_GeomFromGML — In geometric form GML Representation as input , And the output PostGIS Geometry object
ST_GeomFromGeoJSON — Set the geometry's geojson Representation as input , And the output PostGIS Geometric object
ST_GeomFromKML — Set the geometry's KML Representation as input , And the output PostGIS Geometric object
ST_GeomFromTWKB — from TWKB（“Tiny Well-Known Binary”） Geometry represents creating geometry instances .
ST_GMLToSQL — from GML Means to return the specified ST\U Geometry values . This is a ST_GeomFromGML Another name for
ST_LineFromEncodedPolyline — Create line strings from encoded polylines .
ST_PointFromGeoHash — from GeoHash String returns a point .

5.9 Geometry output
These functions convert geometry objects to various text or binary formats .

5.9.1. Well-Known Text (WKT)
ST_AsEWKT — Return with SRID Known text of the geometry of the metadata （WKT） Express .
ST_AsText — Return without SRID Metadata Geometry / Known text of a geographic graphic （WKT） Representation form .

5.9.2. Well-Known Binary (WKB)
ST_AsBinary — Return without SRID The geometry of metadata / Known binary of geography （WKB） Express .
ST_AsEWKB — Return with SRID Known binary of the geometry of metadata （WKB） Express .
ST_AsHEXEWKB — Use the small end （NDR） Or big end （XDR） Code return HEXEWKB Formatted geometry （ As text ）.

5.9.3. Other formats
ST_AsEncodedPolyline — from LineString Geometry returns encoded polylines .
ST_AsGeobuf — Returns a set of rows Geobuf Representation form .
ST_AsGeoJSON — Treat geometry as GeoJSON Element returns .
ST_AsGML — Treat geometry as GML edition 2 or 3 Element returns .
ST_AsKML — Treat geometry as KML Element returns . Several variants . The default version =2, Default maxdecimaldigits=15
ST_AsLatLonText — Returns the degree of a given point 、 branch 、 Second representation .
ST_AsMVTGeom — Convert geometry to Mapbox Coordinate space of vector block .
ST_AsMVT — Returns a set of rows Mapbox An aggregate function represented by a vector tile .
ST_AsSVG — Returns the of the geometry SVG Path data .
ST_AsTWKB — Returns the geometry to TWKB, Also known as “Tiny Well-Known Binary”
ST_AsX3D — return X3D xml Geometry in node element format ： ISO-IEC-19776-1.2-X3DEncodings-XML
ST_GeoHash — Returns the of the geometry GeoHash Representation form .

5.11 Spatial relations
These functions determine the spatial relationship between geometric figures .

5.11.1 Topological relationship
ST_3DIntersects — If two geometries are 3D Intersect in space , Then return to true- For points only , String , polygon , Polyhedral surface （ Area ）.
ST_Contains — If and only if B The point of is not at A And B At least one point of the interior of is located at A When inside , To return to true.
ST_ContainsProperly — If B And A The interior, not the boundary （ Or outside ） The intersection , Then return to true. A It does not contain itself , But it contains itself .
ST_Covers — If B There is no point in A outside , Then return to true
ST_CoveredBy — If Geometry / Geography A There is no point in Geometry / Geography B outside , Then return to true
ST_Crosses — If two geometries have some, but not all, internally identical points , Then return to true.
ST_LineCrossingDirection — Return a number , Indicates two LineString The cross act of .
ST_Disjoint — If two geometries do not intersect in space （ They have nothing in common ）, Then return to true.
ST_Equals — If two geometries contain the same set of points in space , Then return to true.
ST_Intersects — If two “ The geometric ” /“ Geography ” stay 2D Intersect spatially （ At least one thing in common ）, Then return to true.
ST_OrderingEquals — If two geometries represent the same geometry and have the same direction order of points , Then return to true.
ST_Overlaps — If two geometries intersect and have the same size , But they do not completely contain each other , Then return to true.
ST_Relate — Tests whether the two geometries have a relation to the given “ Intersection matrix ” Topological relation of pattern matching , Or calculate their “ Intersection matrix ”
ST_RelateMatch — test DE-9IM Whether the intersection matrix matches the pattern of the intersection matrix
ST_Touches — If two geometries have at least one thing in common , But their interiors don't intersect , Then return to true.
ST_Within — If Geometry A Completely in Geometry B Inside , Then return to true

5.11.2 Distance relationship
ST_3DDWithin — If two 3D The geometry is in a given 3D Within the distance , Then return to true
ST_3DDFullyWithin — If two 3D The geometry is completely in the given 3D Within the distance , Then return to true
ST_DFullyWithin — If two geometries are completely within a given distance , Then return to true
ST_DWithin — If two geometries are within a given distance , Then return to true
ST_PointInsideCircle — Test whether the point geometry is within the circle defined by the center and radius .

5.12 Measurement function
ST_Area — Returns the area of polygon geometry .
ST_Azimuth — Returns the azimuth based on North , In radians , From the point of A The vertical direction to the point B The angle of is in radians .
ST_Angle — return 3 Between points or 2 The angle between two vectors （4 A point or 2 line ）.
ST_ClosestPoint — return g1 It's closest to g2 Of 2D spot . This is the first point of the shortest line .
ST_3DClosestPoint — return g1 It's closest to g2 Of 3D spot . This is a 3D The first point of the shortest line .
ST_Distance — Returns the distance between two geometric or geographic values .
ST_3DDistance — Returns the distance between two geometries in projected units 3D Cartesian minimum distance （ Based on spatial reference ）.
ST_DistanceSphere — Use the spherical earth model to return two lon / lat Minimum distance between geometries （ In meters ）.
ST_DistanceSpheroid — Use the spherical earth model to return two lon / lat Minimum distance between geometries .
ST_FrechetDistance — Returns the... Between two geometries Fréchet distance .
ST_HausdorffDistance — Returns the... Between two geometries Hausdorff distance .
ST_Length — Returns linear geometry 2D length .
ST_Length2D — Returns linear geometry 2D length . ST_Length Another name for
ST_3DLength — Returns linear geometry 3D length .
ST_LengthSpheroid — Return to the sphere lon / lat geometric 2D or 3D length / Perimeter .
ST_LongestLine — Returns the... Between two geometries 2D The longest line .
ST_3DLongestLine — Returns the... Between two geometries 3D The longest line
ST_MaxDistance — Returns the maximum 2D distance between two geometries in projected units .
ST_3DMaxDistance — Returns the distance between two geometries in projected units 3D Cartesian maximum distance （ Based on spatial reference ）.
ST_MinimumClearance — Returns the minimum clearance of the geometry , Measure the robustness of geometry .
ST_MinimumClearanceLine — Returns the two points that span the geometric minimum gap LineString.
ST_Perimeter — Returns the length of a polygon's geometric or geographic boundary .
ST_Perimeter2D — Returns the polygon geometry 2D Perimeter . ST_Perimeter Another name for .
ST_3DPerimeter — Returns the polygon geometry 3D Perimeter .
ST_Project — Returns a distance and azimuth projected from the starting point （ azimuth ） The point of .
ST_ShortestLine — Returns the... Between two geometries 2D The shortest line
ST_3DShortestLine — Returns the... Between two geometries 3D The shortest line

5.13 Stack function
These functions calculate the result of the superposition of two geometric figures . These are also known as point set theory Boolean operations . It also provides some related functions .
ST_ClipByBox2D — Returns part of the geometry that belongs to a rectangle .
ST_Difference — Returns the representation geometry A And geometry B The geometry of the intersecting parts .
ST_Intersection — Returns the representation geometry A and B Geometry of the shared part .
ST_MemUnion — Aggregate functions , Merge geometry in a memory efficient but slow way
ST_Node — A collection of nodal lines .
ST_Split — Returns a collection of geometry created by splitting one geometry into another .
ST_Subdivide — Line subdivision of computational geometry .
ST_SymDifference — Returns a geometry , Represents disjoint geometry A and B Part of .
ST_Union — Returns the geometry that represents the union of the point sets of the input Geometry .
ST_UnaryUnion — Calculates the union of components of a single geometry .

5.14 Geometric treatment
These functions calculate the geometry , Or change the geometry or shape
ST_Buffer — Return a geometry , This geometry covers all points within a given distance from the geometry .ST_BuildArea — Create polygonal geometry consisting of geometric lines .
ST_Centroid — Returns the geometric center of the geometry .ST_ConcaveHull — Calculates concave geometry that may contain all input geometry vertices
ST_ConvexHull — Convex hull of computational geometry .ST_DelaunayTriangles — Returns the of a geometric vertex Delaunay Triangulation .
ST_FilterByM — According to the vertex M Value to remove the vertex
ST_GeneratePoints — Generate random points contained in a polygon or polygon .
ST_GeometricMedian — return MultiPoint Geometric median of .
ST_MaximumInscribedCircle — Calculate the maximum circle completely contained in the geometry .
ST_MinimumBoundingCircle — Returns the smallest circular polygon containing geometry .
ST_MinimumBoundingRadius — Returns the center point and radius of the smallest circle containing geometry .
ST_OrientedEnvelope — Returns a rectangle containing the smallest area of geometry .
ST_OffsetCurve — Returns the offset line at a given distance and margin from the input line .
ST_PointOnSurface — Returns a point guaranteed to lie on a polygon or geometry .
ST_Polygonize — Calculates the set of polygons formed by the lines of a set of geometric figures .
ST_ReducePrecision — Returns a valid Geometry , All points are rounded to the grid tolerance provided .
ST_SharedPaths — Returns a string containing two input lines / A collection of paths shared by multiline strings .
ST_Simplify — Use Douglas-Peucker The algorithm returns a simplified version of the geometry .
ST_SimplifyPreserveTopology — Use Douglas-Peucker The algorithm returns a simplified and valid version of the geometry .
ST_SimplifyVW — Use Visvalingam-Whyatt The algorithm returns a simplified version of the geometry
ST_ChaikinSmoothing — Use Chaikin The algorithm returns a smoothed version of the geometry
ST_SetEffectiveArea — Use Visvalingam-Whyatt The algorithm sets the effective area of each vertex .
ST_VoronoiLines — Returns the of a geometric vertex Voronoi The boundary of a graph .
ST_VoronoiPolygons — Returns the of a geometric vertex Voronoi The pixel of a graph .

5.15 Affine transformation
These functions use affine transformations to change the position and shape of geometry .
ST_Affine — take 3D Affine transformation applied to geometry .
ST_Rotate — Rotate the geometry around the origin .
ST_RotateX — Around the X Axis rotation geometry .
ST_RotateY — around Y Axis rotation geometry .
ST_RotateZ — Around the Z Axis rotation geometry .
ST_Scale — Scale geometry by a given factor .
ST_Translate — Convert geometry at a given offset .
ST_TransScale — Translate and scale geometry by a given offset and coefficient .

5.16 Aggregation function
These functions implement the clustering algorithm of geometric sets .
ST_ClusterDBSCAN — Window function , Use DBSCAN The algorithm returns a cluster for each input geometry ID.
ST_ClusterIntersecting — Aggregate functions , Used to cluster input geometries into connected sets .
ST_ClusterKMeans — Window function , Use K-means The algorithm returns a cluster for each input geometry ID.
ST_ClusterWithin — Aggregate functions , Used to cluster input geometry by separation distance .

5.17 Border function
These functions generate or manipulate bounding boxes . By using automatic or explicit type conversions , They can also provide and accept geometric values .
Box2D — Returns the representation geometry 2D Scope BOX2D.
Box3D — Returns the representative Geometry 3D Scope BOX3D.
ST_EstimatedExtent — Returns the of the spatial table “ It is estimated that ” Range .
ST_Expand — Returns the bounding box extended from another bounding box or geometry .
ST_Extent — An aggregate function , This function returns the bounding box that encloses the geometric row .
ST_3DExtent — An aggregate function , This function returns 3D Bounding box , This bounding box limits the rows of geometry .
ST_MakeBox2D — Created by two 2D Defined by point geometry BOX2D.
ST_3DMakeBox — Created by two 3D Defined by point geometry BOX3D.
ST_XMax — return 2D or 3D Of a bounding box or geometry X Maximum .
ST_XMin — return 2D or 3D Bounding box or geometric X minimum value .
ST_YMax — return 2D or 3D Bounding box or geometric Y Maximum .
ST_YMin — return 2D or 3D Bounding box or geometric Y minimum value .
ST_ZMax — return 2D or 3D Bounding box or geometric Z Maximum .
ST_ZMin — return 2D or 3D Bounding box or geometric Z minimum value .

5.18 Linear reference
ST_LineInterpolatePoint — Returns the point interpolated along a line . The second parameter is a value between 0 and 1 Between float8, Represents a portion of the total length of the string that must locate the point .
ST_3DLineInterpolatePoint — Return edge 3D The point at which the line is inserted . The second parameter is a value between 0 and 1 Between float8, Represents a portion of the total length of the string that must locate the point .
ST_LineInterpolatePoints — Returns one or more points interpolated along a line .
ST_LineLocatePoint — return 0 To 1 The floating point number between , Express LineString Above and given Point The position of the nearest point , To sum up 2d A part of the line length indicates .
ST_LineSubstring — Returns a string , This string is the input substring , From total 2d Start and end of a given fraction of length . The second and third parameters are between 0 and 1 Between float8 value .
ST_LocateAlong — Returns the derived geometry set value with elements that match the specified metric . Polygon elements are not supported .
ST_LocateBetween — Returns the derived geometry set value , Its elements correspond to the specified range （ Including the scope ） Match .
ST_LocateBetweenElevations — Returns the derived geometry （ aggregate ） value , Its elements intersect the specified elevation range .
ST_InterpolatePoint — Returns the value of the measured dimension of the geometry at a point close to the point provided .
ST_AddMeasure — Returns the derived geometry of the measurement element with linear interpolation between the start and end points .

5.19 locus function
These functions support the use of trajectories . The trajectory has a metric on every coordinate (M value ) Linear geometry of . The measured value must increase in a straight line . Spatiotemporal data can be obtained by using relative time ( Such as epoch) Model as a measure .
ST_IsValidTrajectory — If geometry is a valid trajectory , Then return to true.
ST_ClosestPointOfApproach — Returns the closest measurement of the points interpolated along two tracks .
ST_DistanceCPA — Returns the distance between the closest points of two tracks .
ST_CPAWithin — If the closest point of two tracks is within the specified distance , Then return to true.

5.20 SFCGAL function
SFCGAL It's a circle CGAL Of c++ Packing house , Provides advanced 2D and 3D Space function . For robustness , Geometric coordinates have an exact rational representation .
The installation instructions for this library can be found in SFCGAL Home page (http://www.sfcgal.org) Found on the . To enable these functions , Please use create extension postgis_sfcgal.
postgis_sfcgal_version — Returns the in use SFCGAL Version of
ST_Extrude — Extrude the surface to the relevant volume
ST_StraightSkeleton — Calculate the line skeleton from the geometry
ST_CloseMedialAxis — Calculate the approximate intermediate axis of the plane geometry .
ST_IsPlanar — Check if the surface is flat
ST_Orientation — Orient the surface
ST_ForceLHR — mandatory LHR Direction
ST_MinkowskiSum — perform Minkowski and
ST_ConstrainedDelaunayTriangles — Returns a constraint around a given input geometry Delaunay Triangulation .
ST_3DIntersection — perform 3D The intersection
ST_3DDifference — perform 3D differences
ST_3DUnion — perform 3D Merge
ST_3DArea — Calculation 3D The area of the surface geometry . For entities, returns 0.
ST_Tesselate — Perform surface tessellation on polygonal or polyhedral surfaces , And TIN or TINS The form of the collection returns
ST_Volume — Calculation 3D The volume of a solid . If applied to a surface （ Even close ） The geometric , Will return to 0.
ST_MakeSolid — Convert geometry to solids . Do not perform checks . To get a valid entity , The input geometry must be a closed polyhedral surface or a closed TIN.
ST_IsSolid — Test whether the geometry is solid . Do not perform validity checks .

format conversion
ST_Force2D(geom) postgres 3D data cannot be previewed in
ST_AsText(geom) wkb turn wkt
ST_AsGeoJSON(geom) wkb turn geojson

Geometric treatment
ST_LineMerge(ST_Union(geoms)) Segment join merge , Low efficiency , But for most scenarios
ST_MakeLine(geoms) The efficiency of segment connection and merging is high , But the direction is strictly required to be consistent
ST_SimplifyPreserveTopology(geometry ,< threshold >) Geometric thinning

Geometry query
ST_Numgeometries(geom) Calculation mulit The type contains the number of geometries
ST_GeometryN(geom,index) obtain mulit The number of monomer geometries in the type
ST_Lenght(geom) Calculate the length

Topological relationship
ST_Intersects Intersecting relationship , There is a common part between the two figures , For example, public points , Public lines , Public face
ST_Disjoint Separation relationship , The two figures have nothing in common , And ST_Intersects The opposite
ST_Contains Inclusion relation , graphics A Include graphics B：ST_Contains(A,B), If the point is in the face , The line is in the plane .
ST_Within Be included in a relationship , graphics A By B contain :ST_Within(A,B), And ST_Contains The opposite .
ST_Covers Covering relationships , graphics A Completely covering the graphics B：ST_Covers (A,B), Part of the relationship is with ST_Contains overlap , But it's not exactly the same .
ST_Crosses Through relationships , graphics A And graphics B There are some public interior points , But not all .
ST_Equals Equality relation , The two figures are exactly equal .
ST_Overlaps This relationship
ST_Touches Connected relationship , Only the boundary between the two figures has a common connection relationship .