23UML与面向对象_23_.pptVIP

Feature datasets A feature dataset is composed of feature classes that have been grouped together so they can participate in topological relationships with each other. All the feature classes in a feature dataset must share the same spatial reference (or coordinate system) Edits you make to one feature class may result in edits being made automatically to some or all of the other feature classes in the feature dataset In the CityWater geodatabase, three point feature classes and one line feature class were grouped into the PublicWater feature dataset to create a geometric network called WaterNet. Source: Geodatabase Feature Class Feature class is a relational table with a special field for geometric shape Types include point, line polygon, annotation, simple and complex junctions, simpleand complex edges Feature classes can be extended to custom feature classes Geodatabase Point Features Point Multipoint Network junction Geodatabase Line Features Polylines can have one or many paths Paths consist of four segment types: Line Circular arc Elliptical arc Bézier curve Geometric networks contain junctions and edges that form a one-dimensional network GeodatabasePolygon Features A polygon is made from one or many rings (closed non-intersecting paths) Rings can be singular, disjoint, or nested Like polylines, polygons can have lines, circular arcs, elliptic arcs, and Bézier curves Geodatabase Features Relationships Constraints Rules Topology Behavior Smart Features Geodatabase features can have behavior They can also be aware of each other Context This is the key to moving fromgeometry to geography Geodatabase Features Shapes Spatial reference Attributes Subtypes Tables Feature class tables and nonspatial attribute tables. Both types of tables are created and managed in ArcCatalog and edited in ArcMap. Both display in the traditional row-and-column format. The difference is that feature class tables have one or more columns that store feat