Resumen
A PointGeometry object is a shape that has neither length nor area at a given scale.
Debate
En muchos flujos de trabajo de geoprocesamiento, puede que necesite ejecutar una operación concreta utilizando información de coordenadas y geometría, pero que no necesariamente desee pasar por el proceso de crear una nueva clase de entidad (temporal), llenar la clase de entidad con cursores, utilizar la clase de entidad y, a continuación, eliminar la clase de entidad temporal. En su lugar, puede utilizar objetos de geometría tanto para la entrada como para la salida con el fin de facilitar el geoprocesamiento. Los objetos de geometría se pueden crear desde cero usando clases Geometry, Multipoint, PointGeometry, Polygon o Polyline.
During the creation of a geometry object, a simplification process is performed to make the geometry topologically consistent according to its geometry type. For instance, it rectifies polygons that may be self-intersecting or contain incorrect ring orientations. Coordinates may move within the resolution of the geometry's spatial reference.
The following operators can be used in place of geometry methods:
Python operator | Geometry method |
---|---|
+ | intersect |
| | union |
- | difference |
^ | symmetricDifference |
== | equals |
!= | not equals |
For example, to union two geometry objects, g3 = g1 | g2 is equivalent to g3 = g1.union(g2).
The + operator will use the geometry type (dimension) of the first geometry to determine the geometry type of the output.
Sintaxis
PointGeometry (inputs, {spatial_reference}, {has_z}, {has_m}, {has_id})
Parámetro | Explicación | Tipo de datos |
inputs | A Point object used to create the object. | Point |
spatial_reference | The spatial reference of the new geometry. (El valor predeterminado es None) | SpatialReference |
has_z | Specifies whether the geometry will be z-enabled. (El valor predeterminado es False) | Boolean |
has_m | Specifies whether the geometry will be m-enabled. (El valor predeterminado es False) | Boolean |
has_id | Specifies whether the geometry will support point IDs. (El valor predeterminado es False) | Boolean |
Propiedades
Propiedad | Explicación | Tipo de datos |
JSON (Sólo lectura) | An Esri JSON representation of the geometry as a string. Sugerencia:The returned string can be converted to a dictionary using the json module's loads function. | String |
WKB (Sólo lectura) | The well-known binary (WKB) representation for OGC geometry. This property provides a portable representation of a geometry value as a contiguous stream of bytes. | Bytearray |
WKT (Sólo lectura) | The well-known text (WKT) representation for OGC geometry. This property provides a portable representation of a geometry value as a text string. Any true curves in the geometry will be densified into approximate curves in the WKT string. | String |
area (Sólo lectura) | The area of a polygon feature. The area is zero for all other feature types. | Double |
centroid (Sólo lectura) | The true centroid if it is within or on the feature; otherwise, it is the label point. | Point |
extent (Lectura y escritura) | The extent of the geometry. | Extent |
firstPoint (Sólo lectura) | The first coordinate point of the geometry. | Point |
hasCurves (Sólo lectura) | Specifies whether the geometry has a curve. | Boolean |
hullRectangle (Sólo lectura) | A space-delimited string of the coordinate pairs of the convex hull rectangle. | String |
isMultipart (Sólo lectura) | Specifies whether the number of parts for the geometry is more than one. | Boolean |
labelPoint (Sólo lectura) | The point at which the label is located. This point is always located within or on a feature. | Point |
lastPoint (Sólo lectura) | The last coordinate of the feature. | Point |
length (Sólo lectura) | The length of the linear feature. The calculation uses 2D Cartesian mathematics. For point and multipoint geometry, the length will be zero. For polygon geometry, the length will be the 2D length of the boundary. | Double |
length3D (Sólo lectura) | The 3D length of the linear feature. The calculation uses 3D Cartesian mathematics. For point and multipoint geometry, the length will be zero. For polygon geometry, the length will be the 3D length of the boundary. Precaución:The operation does not perform unit conversion between the horizontal and the vertical coordinate systems. The x, y, and z coordinates are assumed to be in the same linear unit. Precaución:This property is only available for projected data. | Double |
partCount (Sólo lectura) | The number of geometry parts for the feature. | Integer |
pointCount (Sólo lectura) | The total number of points for the feature. | Integer |
spatialReference (Sólo lectura) | The spatial reference of the geometry. | SpatialReference |
trueCentroid (Sólo lectura) | The center of gravity for a feature. | Point |
type (Sólo lectura) | The geometry type: polygon, polyline, point, or multipoint. | String |
Descripción general del método
Método | Explicación |
angleAndDistanceTo (other, {method}) | Returns a tuple of angle and distance to a point or polygon. |
boundary () | Constructs the boundary of the geometry. |
buffer (distance) | Constructs a polygon at a specified distance from the geometry. |
clip (envelope) | Constructs the intersection of the geometry and the specified extent. |
contains (second_geometry, {relation}) | Indicates if the base geometry contains the comparison geometry. contains is the opposite of within. Only True relationships are shown in this illustration. |
convexHull () | Constructs the geometry that is the minimal bounding polygon such that all outer angles are convex. |
crosses (second_geometry) | Indicates if the two geometries intersect in a geometry of a lesser shape type. Two polylines cross if they share only points in common, at least one of which is not an endpoint. A polyline and an polygon cross if they share a polyline or a point (for vertical line) in common on the interior of the polygon which is not equivalent to the entire polyline. Only True relationships are shown in this illustration. |
difference (other) | Constructs the geometry that is composed only of the region unique to the base geometry but not part of the other geometry. The following illustration shows the results when the red polygon is the source geometry. |
disjoint (second_geometry) | Indicates if the base and comparison geometries share no points in common. Two geometries intersect if disjoint returns False. Only True relationships are shown in this illustration. |
distanceTo (other) | Returns the minimum distance between two geometries. The distance is in the units of the geometry's spatial reference. If the geometries intersect, the minimum distance is 0. Both geometries must have the same projection. |
equals (second_geometry) | Indicates if the base and comparison geometries are of the same shape type and define the same set of points in the plane. This is a 2D comparison only; M and Z values are ignored. Only True relationships are shown in this illustration. |
getGeohash (precision) | Converts a PointGeometry in geographic coordinate system coordinates of latitude and longitude to a geohash string that is accurate to an arbitrary precision within a bounding box in the geohash grid. |
getPart ({index}) | Returns an Array object of Point objects for a particular part of the geometry if an index is specified. If an index is not specified, an Array object containing an Array of Point objects for each geometry part is returned. The getPart method is equivalent to indexing an object; that is, obj.getPart(0) is equivalent to obj[0]. |
intersect (other, dimension) | Constructs a geometry that is the geometric intersection of the two input geometries. Different dimension values can be used to create different shape types. The intersection of two geometries of the same shape type is a geometry containing only the regions of overlap between the original geometries. For faster results, test if the two geometries are disjoint before calling intersect. |
move ({dx}, {dy}, {dz}) | Moves a geometry by specified distances along the x-, y-, and z-axes to create a new geometry. |
overlaps (second_geometry) | Indicates if the intersection of the two geometries has the same shape type as one of the input geometries and is not equivalent to either of the input geometries. Only True relationships are shown in this illustration. |
pointFromAngleAndDistance (angle, distance, {method}) | Returns a point at a given angle in degrees and distance in the units of the geometry's spatial reference using the specified measurement type. |
projectAs (spatial_reference, {transformation_name}) | Projects a geometry and optionally applies a geotransformation. To project a geometry, the geometry must have a spatial reference and not an unknown coordinate system. The new spatial reference system passed to the method defines the output coordinate system. If either spatial reference is unknown, the coordinates will not be changed. The z- and m-values are not changed by the projectAs method. |
scale ({origin}, {sx}, {sy}, {sz}) | Scales a geometry from a specified origin by specified factors along the x-, y-, and z-axes to create a new geometry. The position of a transformed point (or vertex) is given by
The transformation is applied relative to the origin, so that the origin remains stationary while the geometry expands or contracts around it. The position and the direction of the expansion or contraction for the resulting geometries is significantly affected by the origin. The following describes a few possible choices for the origin and its affect on the output:
|
symmetricDifference (other) | Constructs the geometry that is the union of two geometries minus the instersection of those geometries. The two input geometries must be the same shape type. |
toCoordString (notation) | Converts a PointGeometry to the selected coordinate system notation. |
touches (second_geometry) | Indicates if the boundaries of the geometries intersect. Two geometries touch when the intersection of the geometries is not empty, but the intersection of their interiors is empty. For example, a point touches a polyline only if the point is coincident with one of the polyline end points. Only True relationships are shown in this illustration. |
union (other) | Constructs the geometry that is the set-theoretic union of the input geometries. The two geometries being unioned must be the same shape type. |
within (second_geometry, {relation}) | Indicates if the base geometry is within the comparison geometry. within is the opposite operator of contains. Only True relationships are shown in this illustration. The base geometry is within the comparison geometry if the base geometry is the intersection of the geometries and the intersection of their interiors is not empty. within is a Clementini operator, except in the case of an empty base geometry. |
Métodos
angleAndDistanceTo (other, {method})
Parámetro | Explicación | Tipo de datos |
other | The second geometry. If the geometry is a polygon, the distance is measured to the centroid of the polygon. | PointGeometry |
method | The method used to measure distance.
(El valor predeterminado es GEODESIC) | String |
Tipo de datos | Explicación |
tuple | Returns a tuple of angle (in degrees) and distance (in meters) to another point. |
boundary ()
Tipo de datos | Explicación |
Object | A polygon's boundary is a polyline. A polyline's boundary is a multipoint, corresponding to the endpoints of the line. A point or multipoint's boundary is an empty point or multipoint. |
buffer (distance)
Parámetro | Explicación | Tipo de datos |
distance | The buffer distance. The buffer distance is in the same units as the geometry that is being buffered. A negative distance can only be specified against a polygon geometry. | Double |
Tipo de datos | Explicación |
Polygon | The buffered polygon geometry. |
clip (envelope)
Parámetro | Explicación | Tipo de datos |
envelope | An Extent object used to define the clip extent. | Extent |
Tipo de datos | Explicación |
Object | An output geometry clipped to the specified extent. |
contains (second_geometry, {relation})
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
relation | The spatial relationship type.
(El valor predeterminado es None) | String |
Tipo de datos | Explicación |
Boolean |
A return Boolean value of True indicates this geometry contains the second geometry. |
convexHull ()
Tipo de datos | Explicación |
Object | The resulting geometry. The convex hull of a single point is the point itself. |
crosses (second_geometry)
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
Tipo de datos | Explicación |
Boolean | A return Boolean value of True indicates the two geometries intersect in a geometry of a lesser shape type. |
difference (other)
Parámetro | Explicación | Tipo de datos |
other | A second geometry. | Object |
Tipo de datos | Explicación |
Object | The resulting geometry. |
disjoint (second_geometry)
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
Tipo de datos | Explicación |
Boolean | A return Boolean value of True indicates that the two geometries share no points in common. |
distanceTo (other)
Parámetro | Explicación | Tipo de datos |
other | A second geometry. | Object |
Tipo de datos | Explicación |
Double | The distance between the two geometries. |
equals (second_geometry)
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
Tipo de datos | Explicación |
Boolean |
A return Boolean value of True indicates that the two geometries are of the same shape type and define the same set of points in the plane. |
getGeohash (precision)
Parámetro | Explicación | Tipo de datos |
precision | The precision length of the hash string to return for the PointGeometry. The minimum length is 1 and the maximum length is 20. The default length is 8. (El valor predeterminado es 8) | Integer |
Tipo de datos | Explicación |
String | getGeohash returns a geohash string based on the input point geometry latitude and longitude coordinates and the length of precision. |
The spatial reference of the point geometry must be in a geographic coordinate system to return an accurate geohash.
import arcpy
# Spatial reference set to GCS_WGS_1984
spatial_reference = arcpy.SpatialReference(4326)
pnt = arcpy.Point(-88.236, 40.096)
pnt_geometry = arcpy.PointGeometry(pnt, spatial_reference)
print(pnt_geometry.getGeohash(6)) # dp1k05
getPart ({index})
Parámetro | Explicación | Tipo de datos |
index | The index position of the geometry. | Integer |
Tipo de datos | Explicación |
Array | The resultant Array object. |
intersect (other, dimension)
Parámetro | Explicación | Tipo de datos |
other | The second geometry. | Object |
dimension | The topological dimension (shape type) of the resulting geometry.
| Integer |
Tipo de datos | Explicación |
Object | A new geometry (point, multipoint, polyline, or polygon) that is the geometric intersection of the two input geometries. |
move ({dx}, {dy}, {dz})
Parámetro | Explicación | Tipo de datos |
dx | The distance the geometry will be moved along the x-axis. (El valor predeterminado es 0.0) | Double |
dy | The distance the geometry will be moved along the y-axis. (El valor predeterminado es 0.0) | Double |
dz | The distance the geometry will be moved along the z-axis. The geometry must be z-aware and have z-values. (El valor predeterminado es 0.0) | Double |
Tipo de datos | Explicación |
Geometry | An output geometry, moved by the specified distances along the x-, y-, and z-axes. |
overlaps (second_geometry)
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
Tipo de datos | Explicación |
Boolean | A return Boolean value of True indicates the intersection of the two geometries has the same dimension as one of the input geometries. |
pointFromAngleAndDistance (angle, distance, {method})
Parámetro | Explicación | Tipo de datos |
angle | The angle in degrees to the returned point. | Double |
distance | The distance in the units of the geometry's spatial reference to the returned point. | Double |
method | PLANAR measurements reflect the projection of geographic data onto the 2D surface (in other words, they will not take into account the curvature of the earth). GEODESIC, GREAT_ELLIPTIC, LOXODROME, or PRESERVE_SHAPE measurement types can be chosen as an alternative if desired.
(El valor predeterminado es GEODESIC) | String |
Tipo de datos | Explicación |
PointGeometry | Returns a point at a given angle and distance in degrees and meters. |
projectAs (spatial_reference, {transformation_name})
Parámetro | Explicación | Tipo de datos |
spatial_reference | The spatial reference of the projected geometry. This can be a SpatialReference object or the coordinate system name. | SpatialReference |
transformation_name | The geotransformation name. With ArcGIS Pro, if you do not specify a transformation, none will be applied. With ArcGIS Server, if you do not specify a transformation, a fallback transformation will be applied. | String |
Tipo de datos | Explicación |
Object | The projected geometry. |
scale ({origin}, {sx}, {sy}, {sz})
Parámetro | Explicación | Tipo de datos |
origin | The origin of the transformation. The argument can be either an arcpy.Point object or an arcpy.PointGeometry object. The default origin, arcpy.Point(0.0, 0.0, 0.0), will usually be located outside the target geometry. (El valor predeterminado es arcpy.Point(0.0, 0.0, 0.0)) | Point |
sx | The factor that will be used to scale the geometry along the x-axis. (El valor predeterminado es 1.0) | Double |
sy | The factor that will be used to scale the geometry along the y-axis. (El valor predeterminado es 1.0) | Double |
sz | The factor that will be used to scale the geometry along the z-axis. The geometry must be z-aware and have z-values. (El valor predeterminado es 1.0) | Double |
Tipo de datos | Explicación |
Geometry | An output geometry scaled from the specified origin and by specified factors along the x-, y-, and z-axes. |
symmetricDifference (other)
Parámetro | Explicación | Tipo de datos |
other | A second geometry. | Object |
Tipo de datos | Explicación |
Object | The resulting geometry. |
toCoordString (notation)
Parámetro | Explicación | Tipo de datos |
notation | The coordinate system notation to be generated.
| None |
Tipo de datos | Explicación |
String | The point in the specified coordinate system notation. |
touches (second_geometry)
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
Tipo de datos | Explicación |
Boolean | A return Boolean value of True indicates the boundaries of the geometries intersect. |
union (other)
Parámetro | Explicación | Tipo de datos |
other | A second geometry. | Object |
Tipo de datos | Explicación |
Object | The resulting geometry. |
within (second_geometry, {relation})
Parámetro | Explicación | Tipo de datos |
second_geometry | A second geometry. | Object |
relation | The spatial relationship type.
(El valor predeterminado es None) | String |
Tipo de datos | Explicación |
Boolean | A return Boolean value of True indicates this geometry is contained within the second geometry. |
Muestra de código
Create a point feature class from scratch.
import arcpy
# A list of coordinate pairs
pointList = [[1, 2], [3, 5], [7, 3]]
# Create an empty Point object
point = arcpy.Point()
# A list to hold the PointGeometry objects
pointGeometryList = []
# For each coordinate pair, populate the Point object and create a new
# PointGeometry object
for pt in pointList:
point.X = pt[0]
point.Y = pt[1]
pointGeometry = arcpy.PointGeometry(point)
pointGeometryList.append(pointGeometry)
# Create a copy of the PointGeometry objects, by using pointGeometryList as
# input to the CopyFeatures tool.
arcpy.CopyFeatures_management(pointGeometryList, "c:/geometry/a.gdb/points")