Geometry

Resumen

Geometry objects define a spatial location and an associated geometric shape.

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, para simplificar el geoprocesamiento. Los objetos de geometría se pueden crear utilizando clases Geometry, Multipoint, PointGeometry, Polygon o Polyline .

Sintaxis

Geometry (geometry, inputs, {spatialReference}, {hasZ}, {hasM})

Parámetro	Explicación	Tipo de datos
geometry	The geometry type: point, polygon, polyline, or multipoint.	String
inputs	The coordinates used to create the object. The datatype can be either Point or Array objects.	Object
spatialReference	The spatial reference of the new geometry. (El valor predeterminado es None)	SpatialReference
hasZ	The Z state: True for geometry if Z is enabled and False if it is not. (El valor predeterminado es False)	Boolean
hasM	The M state: True for geometry if M is enabled and False if it is not. (El valor predeterminado es False)	Boolean

Propiedades

Propiedad	Explicación	Tipo de datos
area (Sólo lectura)	The area of a polygon feature. Empty for all other feature types.	Double
centroid (Sólo lectura)	The true centroid if it is within or on the feature; otherwise, the label point is returned. Returns a point object.	Point
extent (Sólo lectura)	The extent of the geometry.	Extent
firstPoint (Sólo lectura)	The first coordinate point of the geometry.	Point
hullRectangle (Sólo lectura)	A space-delimited string of the coordinate pairs of the convex hull rectangle.	String
isMultipart (Sólo lectura)	True, if the number of parts for this geometry is more than one.	Boolean
labelPoint (Sólo lectura)	The point at which the label is located. The labelPoint 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. Zero for point, multipoint feature types.	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
trueCentroid (Sólo lectura)	The center of gravity for a feature.	Point
type (Sólo lectura)	The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, annotation.	String

Vista general del método

Método	Explicación
contains (second_geometry)	Indicates if the base geometry contains the comparison geometry. contains is the opposite of within. Only True relationships are shown in this illustration.
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.
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.
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.
getPart ({index})	Returns an array of point objects for a particular part of geometry or an array containing a number of arrays, one for each part.
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.
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.
within (second_geometry)	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.

Métodos

contains (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

Tipo de datos	Explicación
Boolean	A return Boolean value of True indicates this geometry contains the second geometry.

crosses (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

Tipo de datos	Explicación
Boolean	A return Boolean value of True indicates the two geometries intersect in a geometry of a lesser shape type.

disjoint (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

Tipo de datos	Explicación
Boolean	A return Boolean value of True indicates that the two geometries share no points in common.

equals (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

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.

getPart ({index})

Parámetro	Explicación	Tipo de datos
index	The index position of the geometry.	Integer

Valor de retorno

Tipo de datos	Explicación
Array	getPart returns an array of point objects for a particular part of the geometry if an index is specified. If an index is not specified, an array containing an array of point objects for each geometry part is returned.

overlaps (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

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.

touches (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

Tipo de datos	Explicación
Boolean	A return Boolean value of True indicates the boundaries of the geometries intersect.

within (second_geometry)

Parámetro	Explicación	Tipo de datos
second_geometry	A second geometry.	Object

Valor de retorno

Tipo de datos	Explicación
Boolean	A return Boolean value of True indicates this geometry is contained within the second geometry.

Ejemplo de código

Geometry example

When you set the output parameter of a geoprocessing tool to a empty Geometry object, the tool will return a list of Geometry objects.

import arcpy

# Create an empty Geometry object
#
g = arcpy.Geometry()

# Run the CopyFeatures tool, setting the output to the geometry object.  GeometryList
#  is returned as a list of geometry objects.
#  
geometryList = arcpy.CopyFeatures_management("c:/data/streets.shp", g)

# Walk through each geometry, totalling the length
#
length = 0
for geometry in geometryList:
    length += geometry.length

print "Total length: %f" % length