python arcgis Geometry

Geometry

ArcGIS 10 匯總

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

討論

在許多地理處理工作流程中，您可能需要使用座標和幾何資訊運行特定操作，但不一定想經曆建立新（臨時）要素類、使用游標填充要素類、使用要素類，然後刪除臨時要素類的過程。可以使用幾何對象替代輸入和輸出，從而使地理處理變得更簡單。可以使用 Geometry、Multipoint、PointGeometry、Polygon 或 Polyline 類從頭開始建立幾何對象。

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

參數	說明	資料類型
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. (預設值為None)	SpatialReference
hasZ	The Z state: True for geometry if Z is enabled and False if it is not. (預設值為False)	Boolean
hasM	The M state: True for geometry if M is enabled and False if it is not. (預設值為False)	Boolean

屬性

屬性	說明	資料類型
area (唯讀)	The area of a polygon feature. Empty for all other feature types.	Double
centroid (唯讀)	The true centroid if it is within or on the feature; otherwise, the label point is returned. Returns a point object.	Point
extent (唯讀)	The extent of the geometry.	Extent
firstPoint (唯讀)	The first coordinate point of the geometry.	Point
hullRectangle (唯讀)	A space-delimited string of the coordinate pairs of the convex hull rectangle.	String
isMultipart (唯讀)	True, if the number of parts for this geometry is more than one.	Boolean
labelPoint (唯讀)	The point at which the label is located. The labelPoint is always located within or on a feature.	Point
lastPoint (唯讀)	The last coordinate of the feature.	Point
length (唯讀)	The length of the linear feature. Zero for point, multipoint feature types.	Double
partCount (唯讀)	The number of geometry parts for the feature.	Integer
pointCount (唯讀)	The total number of points for the feature.	Integer
trueCentroid (唯讀)	The center of gravity for a feature.	Point
type (唯讀)	The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, annotation.	String

方法概述

方法	說明
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. 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.

方法 contains (second_geometry)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
Boolean	A return Boolean value of True indicates this geometry contains the second geometry.

crosses (second_geometry)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
Boolean	A return Boolean value of True indicates the two geometries intersect in a geometry of a lesser shape type.

disjoint (second_geometry)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
Boolean	A return Boolean value of True indicates that the two geometries share no points in common.

equals (second_geometry)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
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})

參數	說明	資料類型
index	The index position of the geometry.	Integer

傳回值

資料類型	說明
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)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
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)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
Boolean	A return Boolean value of True indicates the boundaries of the geometries intersect.

within (second_geometry)

參數	說明	資料類型
second_geometry	A second geometry.	Object

傳回值

資料類型	說明
Boolean	A return Boolean value of True indicates this geometry is contained within the second geometry.

程式碼範例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 = 0for geometry in geometryList:    length += geometry.lengthprint "Total length: %f" % length