Polygon (arcpy)

サマリ

A Polygon object is a closed shape defined by a connected sequence of x,y coordinate pairs.

説明

多くのジオプロセシング ワークフローでは、座標とジオメトリの情報を使用して特定の操作を行うことだけが必要で、新しい(一時)フィーチャクラスを作成し、カーソルを使用してフィーチャクラスにデータを設定し、そのフィーチャクラスを使用し、最後に一時フィーチャクラスを削除するというプロセスをすべて行う必要はないことがあります。ジオプロセシングを簡単に実行できるように、入力および出力の両フィーチャクラスの代わりにジオメトリ オブジェクトを使用できます。GeometryMultipointPointGeometryPolygon、または Polyline の各クラスを使用して、ジオメトリ オブジェクトを最初から作成できます。

構文

Polygon (inputs, {spatial_reference}, {has_z}, {has_m})
パラメータ説明データ タイプ
inputs

The coordinates used to create the object. The datatype can be either Point or Array objects.

Object
spatial_reference

The spatial reference of the new geometry.

(デフォルト値は次のとおりです None)

SpatialReference
has_z

The Z state: True for geometry if Z is enabled and False if it is not.

(デフォルト値は次のとおりです False)

Boolean
has_m

The M state: True for geometry if M is enabled and False if it is not.

(デフォルト値は次のとおりです False)

Boolean

特性

プロパティ説明データ タイプ
JSON
(読み取り専用)

Returns a JSON representation of the geometry as a string.

ヒントヒント:

The returned string can be converted to a dictionary using Python's json.loads function.

String
WKB
(読み取り専用)

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
(読み取り専用)

Returns the well-known text (WKT) representation for OGC geometry. It provides a portable representation of a geometry value as a text string.

String
area
(読み取り専用)

The area of a polygon feature. Empty for all other feature types.

Double
centroid
(読み取り専用)

The true centroid if it is within or on the feature; otherwise, the label point is returned. Returns a point object.

Point
extent
(読み書き)

The extent of the geometry.

Extent
firstPoint
(読み取り専用)

The first coordinate point of the geometry.

Point
hullRectangle
(読み取り専用)

A space-delimited string of the coordinate pairs of the convex hull rectangle.

String
isMultipart
(読み取り専用)

True, if the number of parts for this geometry is more than one.

Boolean
labelPoint
(読み取り専用)

The point at which the label is located. The labelPoint is always located within or on a feature.

Point
lastPoint
(読み取り専用)

The last coordinate of the feature.

Point
length
(読み取り専用)

The length of the linear feature. Zero for point and multipoint feature types.

Double
length3D
(読み書き)

The 3D length of the linear feature. Zero for point and multipoint feature types.

Double
partCount
(読み取り専用)

The number of geometry parts for the feature.

Integer
pointCount
(読み取り専用)

The total number of points for the feature.

Integer
spatialReference
(読み取り専用)

The spatial reference of the geometry.

SpatialReference
trueCentroid
(読み取り専用)

The center of gravity for a feature.

Point
type
(読み取り専用)

The geometry type: polygon, polyline, point, multipoint, multipatch, dimension, or annotation.

String

メソッドの概要

メソッド説明
boundary ()

Constructs the boundary of the geometry.

Boundary operator
buffer (distance)

Constructs a polygon at a specified distance from the geometry.

Buffer operator
clip (envelope)

Constructs the intersection of the geometry and the specified extent.

Clip operator
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.

Possible contains relationships
convexHull ()

Constructs the geometry that is the minimal bounding polygon such that all outer angles are convex.

ConvexHull operator
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.

Possible crosses relationships
cut (cutter)

Splits this geometry into a part left of the cutting polyline, and a part right of it.

When a polyline or polygon is cut, it is split where it intersects the cutter polyline. Each piece is classified as left of or right of the cutter. This classification is based on the orientation of the cutter line. Parts of the target polyline that do not intersect the cutting polyline are returned as part of the right of result for that input polyline. If a geometry is not cut, the left geometry will be empty (None).

Cut operator
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.

Difference operator
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.

Possible disjoint relationships
distanceTo (other)

Returns the minimum distance between two geometries. 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.

Possible equals relationships
getArea ({type}, {units})

Returns the area of the feature using a measurement type.

getLength ({measurement_type}, {units})

Returns the length of the feature using a measurement type.

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.

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.

Intersect operator

For faster results, test if the two geometries are disjoint before calling intersect.

measureOnLine (in_point, {as_percentage})

Returns a measure from the start point of this line to the in_point.

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.

Possible overlaps relationships
positionAlongLine (value, {use_percentage})

Returns a point on a line at a specified distance from the beginning of the line.

projectAs (spatial_reference, {transformation_name})

Projects a geometry and optionally applies a geotransformation.

To project, the geometry needs to have a spatial reference, and not have an UnknownCoordinateSystem. 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 measure values are not changed by the ProjectAs method.

queryPointAndDistance (in_point, {as_percentage})

Finds the point on the polyline nearest to the in_point and the distance between those points. Also returns information about the side of the line the in_point is on as well as the distance along the line where the nearest point occurs.

snapToLine (in_point)

Returns a new point based on in_point snapped to this geometry.

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.

symmetricDifference operator
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.

Possible touches relationships
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.

Union operator
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.

Possible within relationships

メソッド

boundary ()
戻り値
データ タイプ説明
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)
パラメータ説明データ タイプ
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
戻り値
データ タイプ説明
Polygon

The buffered polygon geometry.

clip (envelope)
パラメータ説明データ タイプ
envelope

An extent object used to define the clip extent.

Extent
戻り値
データ タイプ説明
Object

An output geometry clipped to the specified extent.

contains (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

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

convexHull ()
戻り値
データ タイプ説明
Object

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

crosses (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

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

cut (cutter)
パラメータ説明データ タイプ
cutter

The cutting polyline geometry.

PolyLine
戻り値
データ タイプ説明
Geometry

A list of two geometries.

difference (other)
パラメータ説明データ タイプ
other

A second geometry.

Object
戻り値
データ タイプ説明
Object

The resulting geometry.

disjoint (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

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

distanceTo (other)
パラメータ説明データ タイプ
other

A second geometry.

Object
戻り値
データ タイプ説明
Double

The distance between the two geometries.

equals (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
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.

getArea ({type}, {units})
パラメータ説明データ タイプ
type

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, and PRESERVE_SHAPE measurement types may be chosen as an alternative, if desired.

  • GEODESICThe 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_ELLIPTICThe 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.
  • LOXODROMEA 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.
  • PLANARPlanar 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_SHAPEThis 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.

(デフォルト値は次のとおりです GEODESIC)

String
units

The units in which the area will be calculated.

Areal unit of measure keywords: ACRES | ARES | HECTARES | SQUARECENTIMETERS | SQUAREDECIMETERS | SQUAREINCHES | SQUAREFEET | SQUAREKILOMETERS | SQUAREMETERS | SQUAREMILES | SQUAREMILLIMETERS | SQUAREYARDS

String
戻り値
データ タイプ説明
Double

The area of the feature.

By default, for Projected coordinate systems, area will be returned in the units of the coordinate system, and for Geographic coordinate systems, area will be returned in square meters.

getLength ({measurement_type}, {units})
パラメータ説明データ タイプ
measurement_type

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, and PRESERVE_SHAPE measurement types may be chosen as an alternative, if desired.

  • GEODESICThe 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_ELLIPTICThe 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.
  • LOXODROMEA 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.
  • PLANARPlanar 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_SHAPEThis 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.

(デフォルト値は次のとおりです GEODESIC)

String
units

The units in which the length will be calculated.

Linear unit of measure keywords: CENTIMETERS | DECIMETERS | FEET | INCHES | KILOMETERS | METERS | MILES | MILLIMETERS | NAUTICALMILES | YARDS

String
戻り値
データ タイプ説明
Double

The length of the feature.

By default, for Projected coordinate systems, length will be returned in the units of the coordinate system, and for Geographic coordinate systems, length will be returned in square meters.

getPart ({index})
パラメータ説明データ タイプ
index

The index position of the geometry.

Integer
戻り値
データ タイプ説明
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.

intersect (other, dimension)
パラメータ説明データ タイプ
other

The second geometry.

Object
dimension

The topological dimension (shape type) of the resulting geometry.

  • 1A zero-dimensional geometry (point or multipoint).
  • 2A one-dimensional geometry (polyline).
  • 4A two-dimensional geometry (polygon).
Integer
戻り値
データ タイプ説明
Object

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

measureOnLine (in_point, {as_percentage})
パラメータ説明データ タイプ
in_point

A point (PointGeometry or Point) that is used to measure from the start point of the polyline.

PointGeometry
as_percentage

If False, the measure will be returned as a distance; if True, the measure will be returned as a percentage.

(デフォルト値は次のとおりです False)

Boolean
戻り値
データ タイプ説明
Double

A distance or percentage.

overlaps (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

A return Boolean value of True indicates the intersection of the two geometries has the same dimension as one of the input geometries.

positionAlongLine (value, {use_percentage})
パラメータ説明データ タイプ
value

The distance along the line.

If the distance is less than zero, then the starting point of the line will be returned; if the distance is greater than the length of the line, then the end point of the line will be returned.

Double
use_percentage

The distance may be specified as a fixed unit of measure or a ratio of the length of the line.

If True, value is used as a percentage; if False, value is used as a distance. For percentages, the value should be expressed as a double from 0.0 (0%) to 1.0 (100%).

(デフォルト値は次のとおりです False)

Boolean
戻り値
データ タイプ説明
PointGeometry

The point on the line at a specified distance from the beginning of the line.

projectAs (spatial_reference, {transformation_name})
パラメータ説明データ タイプ
spatial_reference

The new spatial reference. This can be a SpatialReference object or the coordinate system name.

SpatialReference
transformation_name

The geotransformation name.

String
戻り値
データ タイプ説明
Object

The projected geometry.

queryPointAndDistance (in_point, {as_percentage})
パラメータ説明データ タイプ
in_point

The input point (PointGeometry or Point).

PointGeometry
as_percentage

If False, the measure will be returned as a distance; if True, the measure will be returned as a percentage.

(デフォルト値は次のとおりです False)

Boolean
戻り値
データ タイプ説明
tuple

Returns a tuple that includes the following:

  • A PointGeometry that is the nearest point on the polyline to the in_point.
  • The distance between the start point of the line and the returned point on the line.
  • The minimum distance between the line and the in_point.
  • A Boolean that indicates if the in_point is on the right side of the line. The direction of the line determines the right and left sides.
snapToLine (in_point)
パラメータ説明データ タイプ
in_point

A point (PointGeometry or Point) to be snapped to the line.

PointGeometry
戻り値
データ タイプ説明
PointGeometry

The snapped point.

symmetricDifference (other)
パラメータ説明データ タイプ
other

A second geometry.

Object
戻り値
データ タイプ説明
Object

The resulting geometry.

touches (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

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

union (other)
パラメータ説明データ タイプ
other

A second geometry.

Object
戻り値
データ タイプ説明
Object

The resulting geometry.

within (second_geometry)
パラメータ説明データ タイプ
second_geometry

A second geometry.

Object
戻り値
データ タイプ説明
Boolean

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

コードのサンプル

Polygon example

Create a polygon feature class from scratch.

import arcpy

# A list of features and coordinate pairs
feature_info = [[[1, 2], [2, 4], [3, 7]],
                [[6, 8], [5, 7], [7, 2], [9, 5]]]

# A list that will hold each of the Polygon objects
features = []

for feature in feature_info:
    # Create a Polygon object based on the array of points
    # Append to the list of Polygon objects
    features.append(
        arcpy.Polygon(
            arcpy.Array([arcpy.Point(*coords) for coords in feature])))

# Persist a copy of the Polyline objects using CopyFeatures
arcpy.CopyFeatures_management(features, "c:/geometry/polygons.shp")

関連トピック

4/26/2014