PointGeometry

Zusammenfassung

A PointGeometry object is a shape that has neither length nor area at a given scale.

Diskussion

Bei vielen Workflows der Geoverarbeitung möchten Sie eventuell bestimmte Vorgänge mit Koordinaten- und Geometriedaten ausführen, jedoch nicht unbedingt eine neue (temporäre) Feature-Class erstellen, diese mit Cursorn füllen, die Feature-Class verwenden und dann die vorläufige Feature-Class wieder löschen. Sie können anstelle von Eingabe und Ausgabe auch Geometrieobjekte verwenden und so die Geoverarbeitung vereinfachen. Geometrieobjekte können von Grund auf neu mit Geometry-, Multipoint-, PointGeometry-, Polygon- oder Polyline-Classes erstellt werden.

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 numeric operators can be used in place of geometry methods:

Geometry method	Numeric operator
intersect	+
union	|
difference	-
symmetricDifference	^

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.

Syntax

 PointGeometry  (inputs, {spatial_reference}, {has_z}, {has_m})

Parameter	Erläuterung	Datentyp
inputs	The Point used to create the object.	Point
spatial_reference	The spatial reference of the new geometry. (Der Standardwert ist None)	SpatialReference
has_z	The Z state: True for geometry if Z is enabled and False if it is not. (Der Standardwert ist False)	Boolean
has_m	The M state: True for geometry if M is enabled and False if it is not. (Der Standardwert ist False)	Boolean

Eigenschaften

Eigenschaft	Erläuterung	Datentyp
JSON (Schreibgeschützt)	Returns an Esri JSON representation of the geometry as a string. Tipp: The returned string can be converted to a dictionary using the json module's loads function.	String
WKB (Schreibgeschützt)	Returns the well-known binary (WKB) representation for OGC geometry. It provides a portable representation of a geometry value as a contiguous stream of bytes.	Bytearray
WKT (Schreibgeschützt)	Returns the well-known text (WKT) representation for OGC geometry. It 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 (Schreibgeschützt)	The area of a polygon feature. It is zero for all other feature types.	Double
centroid (Schreibgeschützt)	The true centroid if it is within or on the feature; otherwise, the label point is returned.	Point
extent (Lesen und schreiben)	The extent of the geometry.	Extent
firstPoint (Schreibgeschützt)	The first coordinate point of the geometry.	Point
hasCurves (Schreibgeschützt)	Returns True if the geometry has a curve.	Boolean
hullRectangle (Schreibgeschützt)	A space-delimited string of the coordinate pairs of the convex hull rectangle.	String
isMultipart (Schreibgeschützt)	Returns True if the number of parts for this geometry is more than one.	Boolean
labelPoint (Schreibgeschützt)	The point at which the label is located. The labelPoint is always located within or on a feature.	Point
lastPoint (Schreibgeschützt)	The last coordinate of the feature.	Point
length (Schreibgeschützt)	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 (Schreibgeschützt)	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. Vorsicht: 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. Vorsicht: This property is only available for projected data.	Double
partCount (Schreibgeschützt)	The number of geometry parts for the feature.	Integer
pointCount (Schreibgeschützt)	The total number of points for the feature.	Integer
spatialReference (Schreibgeschützt)	The spatial reference of the geometry.	SpatialReference
trueCentroid (Schreibgeschützt)	The center of gravity for a feature.	Point
type (Schreibgeschützt)	The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, or annotation.	String

Methodenübersicht

Methode	Erläuterung
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)	Gibt an, ob die beiden Geometrien sich in einer Geometrie mit einem geringeren Shape-Typ überschneiden. Zwei Polylinien kreuzen sich, wenn sie nur Punkte gemeinsam haben, von denen mindestens einer kein Endpunkt ist. Eine Polylinie und ein Polygon kreuzen sich, wenn sie im Inneren des Polygons eine Polylinie oder einen Punkt (für eine vertikale Linie) gemeinsam haben, die bzw. der nicht der gesamten Polylinie entspricht. 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)	Gibt an, ob die Basis- und die Vergleichsgeometrie keine gemeinsamen Punkte aufweisen. Zwei Geometrien überschneiden sich, wenn disjoint den Wert False zurückgibt. 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.
overlaps (second_geometry)	Gibt an, üb die Überschneidung der beiden Geometrien denselben Shape-Typ wie eine der Eingabegeometrien aufweist, aber keiner der Eingabegeometrien entspricht. 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, the geometry must have a spatial reference, and not have 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.
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.

Methoden

angleAndDistanceTo (other, {method})

Parameter	Erläuterung	Datentyp
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. GEODESIC—The shortest line between any two points on the earth's surface on a spheroid (ellipsoid). One use for a geodesic line is to determine the shortest distance between two cities for an airplane's flight path. This is also known as a great circle line if based on a sphere rather than an ellipsoid. GREAT_ELLIPTIC—The line on a spheroid (ellipsoid) defined by the intersection at the surface by a plane that passes through the center of the spheroid and the start and endpoints of a segment. This is also known as a great circle when a sphere is used. LOXODROME—The line follows a single compass bearing, or azimuth. Great circle routes are often broken into a series of loxodromes, which simplifies navigation. This is also known as a rhumb line. PLANAR—Planar measurements use 2D Cartesian mathematics to calculate lengths and areas. This option is only available when measuring in a projected coordinate system and the 2D plane of that coordinate system will be used as the basis for the measurements. Planar measurements reflect the projection of geographic data onto a 2D surface, and do not account for the curvature of the earth. PRESERVE_SHAPE—This type calculates the area or length of the geometry on the surface of the earth ellipsoid, for geometry defined in a projected or geographic coordinate system. This option preserves the shape of the geometry in its coordinate system. (Der Standardwert ist GEODESIC)	String

Rückgabewert

Datentyp	Erläuterung
tuple	Returns a tuple of angle (in degrees) and distance (in meters) to another point.

boundary ()

Rückgabewert

Datentyp	Erläuterung
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)

Parameter	Erläuterung	Datentyp
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

Rückgabewert

Datentyp	Erläuterung
Polygon	The buffered polygon geometry.

clip (envelope)

Parameter	Erläuterung	Datentyp
envelope	An Extent object used to define the clip extent.	Extent

Rückgabewert

Datentyp	Erläuterung
Object	An output geometry clipped to the specified extent.

contains (second_geometry, {relation})

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object
relation	The spatial relationship type. BOUNDARY— Relationship has no restrictions for interiors or boundaries. CLEMENTINI— Interiors of geometries must intersect. Specifying CLEMENTINI is equivalent to specifying None. This is the default. PROPER— Boundaries of geometries must not intersect. (Der Standardwert ist None)	String

Rückgabewert

Datentyp	Erläuterung
Boolean	A return Boolean value of True indicates this geometry contains the second geometry.

convexHull ()

Rückgabewert

Datentyp	Erläuterung
Object	The resulting geometry. The convex hull of a single point is the point itself.

crosses (second_geometry)

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Boolean	Der boolesche Rückgabetyp "True" gibt an, dass sich die beiden Geometrien in einer Geometrie mit einem geringeren Shape-Typ schneiden.

difference (other)

Parameter	Erläuterung	Datentyp
other	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Object	The resulting geometry.

disjoint (second_geometry)

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Boolean	Der boolesche Rückgabetyp "True" gibt an, dass die beiden Geometrien keine gemeinsamen Punkte aufweisen.

distanceTo (other)

Parameter	Erläuterung	Datentyp
other	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Double	The distance between the two geometries.

equals (second_geometry)

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
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)

Parameter	Erläuterung	Datentyp
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. (Der Standardwert ist 8)	Integer

Rückgabewert

Datentyp	Erläuterung
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})

Parameter	Erläuterung	Datentyp
index	The index position of the geometry.	Integer

Rückgabewert

Datentyp	Erläuterung
Array	The resultant Array object.

intersect (other, dimension)

Parameter	Erläuterung	Datentyp
other	The second geometry.	Object
dimension	The topological dimension (shape type) of the resulting geometry. 1—A zero-dimensional geometry (point or multipoint). 2—A one-dimensional geometry (polyline). 4—A two-dimensional geometry (polygon).	Integer

Rückgabewert

Datentyp	Erläuterung
Object	A new geometry (point, multipoint, polyline, or polygon) that is the geometric intersection of the two input geometries.

overlaps (second_geometry)

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Boolean	Der boolesche Rückgabetyp True gibt an, dass die Überschneidung der beiden Geometrien dieselbe Dimension wie eine der Eingabegeometrien aufweist.

pointFromAngleAndDistance (angle, distance, {method})

Parameter	Erläuterung	Datentyp
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. GEODESIC—The shortest line between any two points on the earth's surface on a spheroid (ellipsoid). One use for a geodesic line is when you want to determine the shortest distance between two cities for an airplane's flight path. This is also known as a great circle line if based on a sphere rather than an ellipsoid. GREAT_ELLIPTIC—The line on a spheroid (ellipsoid) defined by the intersection at the surface by a plane that passes through the center of the spheroid and the start and endpoints of a segment. This is also known as a great circle when a sphere is used. LOXODROME—A loxodrome is not the shortest distance between two points but instead defines the line of constant bearing, or azimuth. Great circle routes are often broken into a series of loxodromes, which simplifies navigation. This is also known as a rhumb line. PLANAR—Planar measurements use 2D Cartesian mathematics to calculate lengths and areas. This option is only available when measuring in a projected coordinate system, and the 2D plane of that coordinate system will be used as the basis for the measurements. PRESERVE_SHAPE—This type calculates the area or length of the geometry on the surface of the earth ellipsoid for geometry defined in a projected or geographic coordinate system. This option preserves the shape of the geometry in its coordinate system. (Der Standardwert ist GEODESIC)	String

Rückgabewert

Datentyp	Erläuterung
PointGeometry	Returns a point at a given angle and distance in degrees and meters.

projectAs (spatial_reference, {transformation_name})

Parameter	Erläuterung	Datentyp
spatial_reference	The new spatial reference. This can be a SpatialReference object or the coordinate system name.	SpatialReference
transformation_name	The geotransformation name.	String

Rückgabewert

Datentyp	Erläuterung
Object	The projected geometry.

symmetricDifference (other)

Parameter	Erläuterung	Datentyp
other	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Object	The resulting geometry.

toCoordString (notation)

Parameter	Erläuterung	Datentyp
notation	The coordinate system notation to be generated. DD— Decimal degrees. For example, 34.05719570N 117.19647020W DDM— Degrees decimal minutes. For example, 34 03.43174200N 117 11.78821200W DDS— Degree Minute Seconds. For example, 34 03 25.90452000N 117 11 47.29272000W GARS— Global Area Reference System. Based on latitude and longitude, it divides and subdivides the world into cells. For example, 126LJ47 GEOREF— World Geographic Reference System. For example, EJCE4821203432 MGRS— Military Grid Reference System. For example, 11SMT8186968515 USNG— United States National Grid. For example, 11S MT 81869 68515 UTM— Universal Transverse Mercator. For example, 11S 481868 3768515 UTMNS— Universal Transverse Mercator (no spaces). For example, 11N4818683768515	None

Rückgabewert

Datentyp	Erläuterung
String	The point in the chosen coordinate system notation.

touches (second_geometry)

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Boolean	A return Boolean value of True indicates the boundaries of the geometries intersect.

union (other)

Parameter	Erläuterung	Datentyp
other	A second geometry.	Object

Rückgabewert

Datentyp	Erläuterung
Object	The resulting geometry.

within (second_geometry, {relation})

Parameter	Erläuterung	Datentyp
second_geometry	A second geometry.	Object
relation	The spatial relationship type. BOUNDARY— Relationship has no restrictions for interiors or boundaries. CLEMENTINI— Interiors of geometries must intersect. Specifying CLEMENTINI is equivalent to specifying None. This is the default. PROPER— Boundaries of geometries must not intersect. (Der Standardwert ist None)	String

Rückgabewert

Datentyp	Erläuterung
Boolean	A return Boolean value of True indicates this geometry is contained within the second geometry.

Codebeispiel

PointGeometry example

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")