Lines and polygon in ArcGIS

This article describes in detail the structural relationship between the line, multiple line segments, and polygon in ArcGIS.

In the definition of ArcGIS, the class structure view of the Line Section is as follows:

You can intuitively see its structural relationship.

I. line segments (isegment)

The line segments in ArcGIS inherit from isegment and are divided into four types. Ibeziercurve, iline, icirculararc, and iellipticarc ). They only have two endpoints connected.

1. Line Segment (iline)

A straight line is directly connected by two points.

2. icirculararc)

An arc line is an arc segment or a complete arc, that is, the starting point and the ending point are at the same point.

3. elliptic arc (iellipticarc)

An elliptical arc is an arc segment of an elliptic. It can be a complete elliptic or any arc segment.

4. ibeziercurve)

Each vertex of the besell curve has two control points, which are used to control the curve radians on both sides of the vertex. It is a mathematical curve applied to two-dimensional graphics applications. A curve has four points: the starting point, the ending point (also called the anchor), and two separated intermediate points. Sliding two intermediate points will change the shape of the besell curve. This type of curve segment is not often used in actual development and application.

For more information about the besell curve, see: http://baike.baidu.com/view/60154.htm

2. An interconnected line (ipath) and a closed connection line (iring)

A graphic ipath composed of one or more line segments connected at the beginning and end. To meet ipath requirements, a line segment must be connected at the beginning and end. Each connection can have only two points. An ipath can be composed of one or more line segments. A closed ipath can be called an iring (similar to a square with equal length and width ).

As shown in, the left side can constitute ipath, and the right side cannot be called ipath.

3. Multiple Line Segments)

Multiple segments are composed of one or more ipath segments. It can be imagined that a single isegment can also constitute an ipolympus line. Closed ipaths (iring) can also form an ipolympus line. Of course, a closed isegment can also form an ipolympus line. An ipolympus line may be connected or scattered, but a multi-line segment is usually composed of an ipath, which is conducive to Data Reading and analysis.

4. Polygon)

A polygon is composed of one or more iring. That is to say, all the images in ipolympus are closed. A single closed isegment can constitute an ipolympus Gon, such as a closed circular arc (icurve) and a closed elliptical arc (iellipticarc ). Polygon can be composed of multiple iring elements that are mutually inclusive, intersecting, or scattered. However, generally, ipolympus GON is composed of one iring, which facilitates data reading and analysis.

V. Curve icurve

In ArcGIS, all line-related graphs inherit icurve, which defines the line connectivity and some operation query methods.

The following table lists the member variables and methods of icurve:

For detailed usage, see the ArcGIS development help document.

Please indicate the source for reprinting.