PointGeometry

Summary

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

Discussion

In many geoprocessing workflows, you may need to run a specific operation using coordinate and geometry information but don't necessarily want to go through the process of creating a new (temporary) feature class, populating the feature class with cursors, using the feature class, then deleting the temporary feature class. Geometry objects can be used instead for both input and output to make geoprocessing easier. Geometry objects can be created from scratch using Geometry, Multipoint, PointGeometry, Polygon, or Polyline classes.

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.

Syntax

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

Parameter	Explanation	Data Type
inputs	The Point used to create the object.	Point
spatial_reference	The spatial reference of the new geometry. (The default value is None)	SpatialReference
has_z	The Z state: True for geometry if Z is enabled and False if it is not. (The default value is False)	Boolean
has_m	The M state: True for geometry if M is enabled and False if it is not. (The default value is False)	Boolean

Properties

Property	Explanation	Data Type
JSON (Read Only)	Returns an Esri JSON representation of the geometry as a string. Tip: The returned string can be converted to a dictionary using the json module's loads function.	String
WKB (Read Only)	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 (Read Only)	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 (Read Only)	The area of a polygon feature. It is zero for all other feature types.	Double
centroid (Read Only)	The true centroid if it is within or on the feature; otherwise, the label point is returned.	Point
extent (Read and Write)	The extent of the geometry.	Extent
firstPoint (Read Only)	The first coordinate point of the geometry.	Point
hasCurves (Read Only)	Returns True if the geometry has a curve.	Boolean
hullRectangle (Read Only)	A space-delimited string of the coordinate pairs of the convex hull rectangle.	String
isMultipart (Read Only)	Returns True if the number of parts for this geometry is more than one.	Boolean
labelPoint (Read Only)	The point at which the label is located. The labelPoint is always located within or on a feature.	Point
lastPoint (Read Only)	The last coordinate of the feature.	Point
length (Read Only)	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 (Read Only)	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. Caution: 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. Caution: This property is only available for projected data.	Double
partCount (Read Only)	The number of geometry parts for the feature.	Integer
pointCount (Read Only)	The total number of points for the feature.	Integer
spatialReference (Read Only)	The spatial reference of the geometry.	SpatialReference
trueCentroid (Read Only)	The center of gravity for a feature.	Point
type (Read Only)	The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, or annotation.	String

Method Overview

Method	Explanation
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.
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, 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.

Methods

angleAndDistanceTo (other, {method})

Parameter	Explanation	Data Type
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. (The default value is GEODESIC)	String

Return Value

Data Type	Explanation
tuple	Returns a tuple of angle (in degrees) and distance (in meters) to another point.

boundary ()

Return Value

Data Type	Explanation
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	Explanation	Data Type
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

Return Value

Data Type	Explanation
Polygon	The buffered polygon geometry.

clip (envelope)

Parameter	Explanation	Data Type
envelope	An Extent object used to define the clip extent.	Extent

Return Value

Data Type	Explanation
Object	An output geometry clipped to the specified extent.

contains (second_geometry, {relation})

Parameter	Explanation	Data Type
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. (The default value is None)	String

Return Value

Data Type	Explanation
Boolean	A return Boolean value of True indicates this geometry contains the second geometry.

convexHull ()

Return Value

Data Type	Explanation
Object	The resulting geometry. The convex hull of a single point is the point itself.

crosses (second_geometry)

Parameter	Explanation	Data Type
second_geometry	A second geometry.	Object

Return Value

Data Type	Explanation
Boolean	A return Boolean value of True indicates the two geometries intersect in a geometry of a lesser shape type.

difference (other)

Parameter	Explanation	Data Type
other	A second geometry.	Object

Return Value

Data Type	Explanation
Object	The resulting geometry.

disjoint (second_geometry)

Parameter	Explanation	Data Type
second_geometry	A second geometry.	Object

Return Value

Data Type	Explanation
Boolean	A return Boolean value of True indicates that the two geometries share no points in common.

distanceTo (other)

Parameter	Explanation	Data Type
other	A second geometry.	Object

Return Value

Data Type	Explanation
Double	The distance between the two geometries.

equals (second_geometry)

Parameter	Explanation	Data Type
second_geometry	A second geometry.	Object

Return Value

Data Type	Explanation
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	Explanation	Data Type
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. (The default value is 8)	Integer

Return Value

Data Type	Explanation
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	Explanation	Data Type
index	The index position of the geometry.	Integer

Return Value

Data Type	Explanation
Array	The resultant Array object.

intersect (other, dimension)

Parameter	Explanation	Data Type
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

Return Value

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

overlaps (second_geometry)

Parameter	Explanation	Data Type
second_geometry	A second geometry.	Object

Return Value

Data Type	Explanation
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})

Parameter	Explanation	Data Type
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. (The default value is GEODESIC)	String

Return Value

Data Type	Explanation
PointGeometry	Returns a point at a given angle and distance in degrees and meters.

projectAs (spatial_reference, {transformation_name})

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

Return Value

Data Type	Explanation
Object	The projected geometry.

symmetricDifference (other)

Parameter	Explanation	Data Type
other	A second geometry.	Object

Return Value

Data Type	Explanation
Object	The resulting geometry.

toCoordString (notation)

Parameter	Explanation	Data Type
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

Return Value

Data Type	Explanation
String	The point in the chosen coordinate system notation.

touches (second_geometry)

Parameter	Explanation	Data Type
second_geometry	A second geometry.	Object

Return Value

Data Type	Explanation
Boolean	A return Boolean value of True indicates the boundaries of the geometries intersect.

union (other)

Parameter	Explanation	Data Type
other	A second geometry.	Object

Return Value

Data Type	Explanation
Object	The resulting geometry.

within (second_geometry, {relation})

Parameter	Explanation	Data Type
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. (The default value is None)	String

Return Value

Data Type	Explanation
Boolean	A return Boolean value of True indicates this geometry is contained within the second geometry.

Code sample

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")