topology.xsd

联合国农粮署牵头开发的geonetwork源代码最新版

<?xml version="1.0" encoding="UTF-8"?>
<schema targetNamespace="http://www.opengis.net/gml" xmlns:gml="http://www.opengis.net/gml" xmlns="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" version="3.2.0">
	<annotation>
		<appinfo source="urn:ogc:specification:gml:schema-xsd:topology:3.2.0">topology.xsd</appinfo>
		<documentation>See ISO/DIS 19136 Clause 14.
Topology is the branch of mathematics describing the properties of objects which are invariant under continuous deformation. For example, a circle is topologically equivalent to an ellipse because one can be transformed into the other by stretching. In geographic modelling, the foremost use of topology is in accelerating computational geometry. The constructs of topology allow characterisation of the spatial relationships between objects using simple combinatorial or algebraic algorithms. Topology, realised by the appropriate geometry, also allows a compact and unambiguous mechanism for expressing shared geometry among geographic features.
There are four instantiable classes of primitive topology objects, one for each dimension up to 3D. In addition, topological complexes are supported, too. 
There is strong symmetry in the (topological boundary and coboundary) relationships between topology primitives of adjacent dimensions. Topology primitives are bounded by directed primitives of one lower dimension. The coboundary of each topology primitive is formed from directed topology primitives of one higher dimension.</documentation>
	</annotation>
	<include schemaLocation="geometryComplexes.xsd"/>
	<complexType name="AbstractTopologyType" abstract="true">
		<annotation>
			<documentation>This abstract type supplies the root or base type for all topological elements including primitives and complexes. It inherits AbstractGMLType and hence can be identified using the gml:id attribute.</documentation>
		</annotation>
		<complexContent>
			<extension base="gml:AbstractGMLType"/>
		</complexContent>
	</complexType>
	<element name="AbstractTopology" type="gml:AbstractTopologyType" abstract="true" substitutionGroup="gml:AbstractGML"/>
	<complexType name="AbstractTopoPrimitiveType" abstract="true">
		<complexContent>
			<extension base="gml:AbstractTopologyType">
				<sequence>
					<element ref="gml:isolated" minOccurs="0" maxOccurs="unbounded"/>
					<element ref="gml:container" minOccurs="0"/>
				</sequence>
			</extension>
		</complexContent>
	</complexType>
	<element name="AbstractTopoPrimitive" type="gml:AbstractTopoPrimitiveType" abstract="true" substitutionGroup="gml:AbstractTopology">
		<annotation>
			<documentation>gml:AbstractTopoPrimitive acts as the base type for all topological primitives. Topology primitives are the atomic (smallest possible) units of a topology complex. 
Each topology primitive may contain references to other topology primitives of codimension 2 or more (gml:isolated). Conversely, nodes may have faces as containers and nodes and edges may have solids as containers (gml:container).</documentation>
		</annotation>
	</element>
	<element name="isolated" type="gml:IsolatedPropertyType">
		<annotation>
			<documentation>The gml:isolated property element implements the role of the same name of the ISO 19107 鈥淚solated In鈥