【转载】Making new features with topology tools(ArcInfo and ArcEditor only)

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Making new features with topology tools(ArcInfo and ArcEditor only)
Release 9.1 Last modified January 25, 2006	Print all topics in : "Editing topology"

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Basic topology tasks

An overview of editing in ArcMap

About making new features with topology tools

You can use topology tools to make new features from existing ones.
In ArcCatalog, you can create a whole new polygon feature class from an
input set of line features. In ArcMap, you can construct new polygon
features from the intersection of selected existing line and polygon
features or create new line features by splitting selected line
features where they cross each other.

Creating polygons from lines in ArcCatalog
In ArcCatalog, the Polygon Feature Class From Lines command takes
one or more existing line or polygon feature classes in a feature
dataset and creates new polygon features from the closed shapes that
are defined by the intersection of all the lines or polygon edges.



You have the option to use a point feature class to supply
attributes for the new polygons. If a point falls within one of the new
polygons, the polygon is assigned the points attributes.

Creating features in ArcMap
In ArcMap, the Construct Features tool


takes selected features from one or more feature classes and creates
new features in the target feature class. The tool uses the input
geometries of the selected features to construct polygons or lines
following polygon boundaries, depending on the geometry of the target
feature class.



You can use this tool to build parcel polygons from selected lot
line features or lake shorelines from selected lake polygon features.



You can also use the Planarize tool to create separate line
features from selected touching or crossing line features. This can be
useful when you have nontopological line work that has been spaghetti
digitized or imported from a computer-aided design (CAD) drawing.



Creating new polygons from lines
Sometimes you need to create polygon features from line feature
data. For example, you might have digitized the boundaries of a set of
features into a line feature class, or you may have only been able to
obtain line features from a data provider. Perhaps you have a detailed
coastline feature class that you would like to use to update some
existing, less detailed data. In ArcCatalog, the Polygon Feature Class
From Lines tool lets you create new polygon features from line and
polygon features in one or more feature classes. You have the option of
specifying a point feature class that will supply attributes for the
new polygon features.

Creating new features from the geometry of exisiting features
Sometimes you need to create new features from the geometry of
existing features. For example, you might need to create a new parcel
feature from some parcel boundary lines or some parcel boundary lines
from parcel features. In ArcMap, you can select features and use their
geometry to create new polygons or lines in the Editor Target Feature
Class. You can create new features from existing features' geometry
using the Construct Features tool.

You can create multiple line features by splitting longer features
at the places where they intersect using the Planarize Lines command

. When Planarize is used on a multipart line feature, it is split at the point of intersection into a new feature.

How to make new features with topology tools

Creating a polygon feature class from lines

(ArcInfo and ArcEditor only)

In ArcCatalog, navigate to the dataset in which you want to create a polygon feature class from an existing line feature class.

Right-click the dataset, point to New, and click Polygon Feature Class From Lines.

Type a name for the new polygon feature class.

Optionally, type a cluster tolerance. The default cluster tolerance is the minimum possible cluster tolerance.

Check the line feature classes that you want to be considered in creating the polygons.

Optionally, choose a point feature class in the dataset to provide attributes for the polygons.

Click OK.

Constructing polygons from the geometry of other features

In ArcMap, click the Edit tool

on the Editor toolbar.

Select the features whose geometry you want to use to construct new polygon features.

On the Editor toolbar, click the Task dropdown arrow and click Create New Feature.

On the Editor toolbar, click the Target dropdown arrow and click
the polygon feature class in which you want to create a new feature.

On the Topology toolbar, click the Construct Features button

.

Optionally, type a cluster tolerance.

Optionally, check the box to consider existing features of the target layer in the current extent.

This will use the boundaries of existing polygons as input geometry
and will split such features where selected lines or polygons cross
them.

Click OK.

The new features are created in the target feature class.

Constructing lines from the geometry of other features

In ArcMap, click the Edit tool

on the Editor toolbar.

Select the features whose geometry you want to use to construct new
line features. In the graphic, the geometry of polygon features is
being used to construct new lines.



On the Editor toolbar, click the Task dropdown arrow and click Create New Feature.

On the Editor toolbar, click the Target dropdown arrow and click
the line feature class in which you want to create a new feature.

On the Topology toolbar, click the Construct Features button

.

Optionally, type a cluster tolerance.

Optionally, check the box to consider existing features of the target layer in the current extent.

This will use existing lines as input geometry and split such features where selected lines or polygons cross them.

Click OK.

The new features are created in the target feature class.

Two lines are created where polygons share boundaries.

Tip

You can use Planarize on lines constructed from polygons that share boundaries to remove overlapping line segments.

Using Planarize to split lines at intersections

In ArcMap, click the Edit tool

on the Editor toolbar.

Select the line features you want to split at intersections.

Click the Planarize Lines button

on the Topology toolbar.

Optionally, type a cluster tolerance.

Click OK.

The lines are split into new features where they intersect.

Planarize
also removes overlapping line segments—such as those created by
constructing lines from polygons that have shared boundaries.