GML Subset schema for gml:Point,gml:LineString,gml:Polygon,gml:LinearRing, written by gmlSubset.xslt. A Point is defined by a single coordinate tuple. GML supports two different ways to specify the direct poisiton of a point. 1. The "pos" element is of type DirectPositionType. Deprecated with GML version 3.1.0 for coordinates with ordinate values that are numbers. Use "pos" instead. The "coordinates" element shall only be used for coordinates with ordinates that require a string representation, e.g. DMS representations. Deprecated with GML version 3.0. Use "pos" instead. The "coord" element is included for backwards compatibility with GML 2. This is the abstract root type of the geometric primitives. A geometric primitive is a geometric object that is not decomposed further into other primitives in the system. All primitives are oriented in the direction implied by the sequence of their coordinate tuples. All geometry elements are derived directly or indirectly from this abstract supertype. A geometry element may have an identifying attribute ("gml:id"), a name (attribute "name") and a description (attribute "description"). It may be associated with a spatial reference system (attribute "srsName"). The following rules shall be adhered: - Every geometry type shall derive from this abstract type. - Every geometry element (i.e. an element of a geometry type) shall be directly or indirectly in the substitution group of _Geometry. This attribute is included for backward compatibility with GML 2 and is deprecated with GML 3. This identifer is superceded by "gml:id" inherited from AbstractGMLType. The attribute "gid" should not be used anymore and may be deleted in future versions of GML without further notice. All complexContent GML elements are directly or indirectly derived from this abstract supertype to establish a hierarchy of GML types that may be distinguished from other XML types by their ancestry. Elements in this hierarchy may have an ID and are thus referenceable. This content model group makes it easier to construct types that derive from AbstractGMLType and its descendents "by restriction". A reference to the group saves having to enumerate the standard object properties. Multiple names may be provided. These will often be distinguished by being assigned by different authorities, as indicated by the value of the codeSpace attribute. In an instance document there will usually only be one name per authority. Contains or refers to a metadata package that contains metadata properties. Base type for complex metadata property types. Attribute group used to enable property elements to refer to their value remotely. It contains the simple link components from xlinks.xsd, with all members optional, and the remoteSchema attribute, which is also optional. These attributes can be attached to any element, thus allowing it to act as a pointer. The 'remoteSchema' attribute allows an element that carries link attributes to indicate that the element is declared in a remote schema rather than by the schema that constrains the current document instance. Reference to an XML Schema fragment that specifies the content model of the propertys value. This is in conformance with the XML Schema Section 4.14 Referencing Schemas from Elsewhere. Contains a simple text description of the object, or refers to an external description. This type is available wherever there is a need for a "text" type property. It is of string type, so the text can be included inline, but the value can also be referenced remotely via xlinks from the AssociationAttributeGroup. If the remote reference is present, then the value obtained by traversing the link should be used, and the string content of the element can be used for an annotation. Label for the object, normally a descriptive name. An object may have several names, typically assigned by different authorities. The authority for a name is indicated by the value of its (optional) codeSpace attribute. The name may or may not be unique, as determined by the rules of the organization responsible for the codeSpace. Name or code with an (optional) authority. Text token. If the codeSpace attribute is present, then its value should identify a dictionary, thesaurus or authority for the term, such as the organisation who assigned the value, or the dictionary from which it is taken. A text string with an optional codeSpace attribute. Database handle for the object. It is of XML type ID, so is constrained to be unique in the XML document within which it occurs. An external identifier for the object in the form of a URI may be constructed using standard XML and XPointer methods. This is done by concatenating the URI for the document, a fragment separator, and the value of the id attribute. Optional reference to the CRS used by this geometry, with optional additional information to simplify use when a more complete definition of the CRS is not needed. In general this reference points to a CRS instance of gml:CoordinateReferenceSystemType (see coordinateReferenceSystems.xsd). For well known references it is not required that the CRS description exists at the location the URI points to. If no srsName attribute is given, the CRS must be specified as part of the larger context this geometry element is part of, e.g. a geometric element like point, curve, etc. It is expected that this attribute will be specified at the direct position level only in rare cases. The "srsDimension" is the length of coordinate sequence (the number of entries in the list). This dimension is specified by the coordinate reference system. When the srsName attribute is omitted, this attribute shall be omitted. Optional additional and redundant information for a CRS to simplify use when a more complete definition of the CRS is not needed. This information shall be the same as included in the more complete definition of the CRS, referenced by the srsName attribute. When the srsName attribute is included, either both or neither of the axisLabels and uomLabels attributes shall be included. When the srsName attribute is omitted, both of these attributes shall be omitted. Ordered list of labels for all the axes of this CRS. The gml:axisAbbrev value should be used for these axis labels, after spaces and forbiddden characters are removed. When the srsName attribute is included, this attribute is optional. When the srsName attribute is omitted, this attribute shall also be omitted. Ordered list of unit of measure (uom) labels for all the axes of this CRS. The value of the string in the gml:catalogSymbol should be used for this uom labels, after spaces and forbiddden characters are removed. When the axisLabels attribute is included, this attribute shall also be included. When the axisLabels attribute is omitted, this attribute shall also be omitted. A set of values, representing a list of token with the lexical value space of NCName. The tokens are seperated by whitespace. DirectPosition instances hold the coordinates for a position within some coordinate reference system (CRS). Since DirectPositions, as data types, will often be included in larger objects (such as geometry elements) that have references to CRS, the "srsName" attribute will in general be missing, if this particular DirectPosition is included in a larger element with such a reference to a CRS. In this case, the CRS is implicitly assumed to take on the value of the containing object's CRS. XML List based on XML Schema double type. An element of this type contains a space-separated list of double values Deprecated with GML version 3.1.0. Tables or arrays of tuples. May be used for text-encoding of values from a table. Actually just a string, but allows the user to indicate which characters are used as separators. The value of the 'cs' attribute is the separator for coordinate values, and the value of the 'ts' attribute gives the tuple separator (a single space by default); the default values may be changed to reflect local usage. Defaults to CSV within a tuple, space between tuples. However, any string content will be schema-valid. Deprecated with GML 3.0 and included for backwards compatibility with GML 2. Use the "pos" element instead. Represents a coordinate tuple in one, two, or three dimensions. Deprecated with GML 3.0 and replaced by DirectPositionType. The "_GeometricPrimitive" element is the abstract head of the substituition group for all (pre- and user-defined) geometric primitives. The "_Geometry" element is the abstract head of the substituition group for all geometry elements of GML 3. This includes pre-defined and user-defined geometry elements. Any geometry element must be a direct or indirect extension/restriction of AbstractGeometryType and must be directly or indirectly in the substitution group of "_Geometry". Global element which acts as the head of a substitution group that may include any element which is a GML feature, object, geometry or complex value This abstract element is the head of a substitutionGroup hierararchy which may contain either simpleContent or complexContent elements. It is used to assert the model position of "class" elements declared in other GML schemas. A LineString is a special curve that consists of a single segment with linear interpolation. It is defined by two or more coordinate tuples, with linear interpolation between them. It is backwards compatible with the LineString of GML 2, GM_LineString of ISO 19107 is implemented by LineStringSegment. GML supports two different ways to specify the control points of a line string. 1. A sequence of "pos" (DirectPositionType) or "pointProperty" (PointPropertyType) elements. "pos" elements are control points that are only part of this curve, "pointProperty" elements contain a point that may be referenced from other geometry elements or reference another point defined outside of this curve (reuse of existing points). 2. The "posList" element allows for a compact way to specifiy the coordinates of the control points, if all control points are in the same coordinate reference systems and belong to this curve only. The number of direct positions in the list must be at least two. Deprecated with GML version 3.1.0. Use "pointProperty" instead. Included for backwards compatibility with GML 3.0.0. Deprecated with GML version 3.0. Use "pos" instead. The "coord" element is included for backwards compatibility with GML 2. Deprecated with GML version 3.1.0. Use "posList" instead. An abstraction of a curve to support the different levels of complexity. The curve can always be viewed as a geometric primitive, i.e. is continuous. This property element either references a point via the XLink-attributes or contains the point element. pointProperty is the predefined property which can be used by GML Application Schemas whenever a GML Feature has a property with a value that is substitutable for Point. A property that has a point as its value domain can either be an appropriate geometry element encapsulated in an element of this type or an XLink reference to a remote geometry element (where remote includes geometry elements located elsewhere in the same document). Either the reference or the contained element must be given, but neither both nor none. This attribute group includes the XLink attributes (see xlinks.xsd). XLink is used in GML to reference remote resources (including those elsewhere in the same document). A simple link element can be constructed by including a specific set of XLink attributes. The XML Linking Language (XLink) is currently a Proposed Recommendation of the World Wide Web Consortium. XLink allows elements to be inserted into XML documents so as to create sophisticated links between resources; such links can be used to reference remote properties. A simple link element can be used to implement pointer functionality, and this functionality has been built into various GML 3 elements by including the gml:AssociationAttributeGroup. Deprecated with GML version 3.1.0. Use "pointProperty" instead. Included for backwards compatibility with GML 3.0.0. DirectPositionList instances hold the coordinates for a sequence of direct positions within the same coordinate reference system (CRS). "count" allows to specify the number of direct positions in the list. If the attribute count is present then the attribute srsDimension shall be present, too. The "_Curve" element is the abstract head of the substituition group for all (continuous) curve elements. A Polygon is a special surface that is defined by a single surface patch. The boundary of this patch is coplanar and the polygon uses planar interpolation in its interior. It is backwards compatible with the Polygon of GML 2, GM_Polygon of ISO 19107 is implemented by PolygonPatch. An abstraction of a surface to support the different levels of complexity. A surface is always a continuous region of a plane. A boundary of a surface consists of a number of rings. In the normal 2D case, one of these rings is distinguished as being the exterior boundary. In a general manifold this is not always possible, in which case all boundaries shall be listed as interior boundaries, and the exterior will be empty. Encapsulates a ring to represent the surface boundary property of a surface. The "_Ring" element is the abstract head of the substituition group for all closed boundaries of a surface patch. An abstraction of a ring to support surface boundaries of different complexity. A boundary of a surface consists of a number of rings. The "interior" rings seperate the surface / surface patch from the area enclosed by the rings. The "_Surface" element is the abstract head of the substituition group for all (continuous) surface elements. A LinearRing is defined by four or more coordinate tuples, with linear interpolation between them; the first and last coordinates must be coincident. GML supports two different ways to specify the control points of a linear ring. 1. A sequence of "pos" (DirectPositionType) or "pointProperty" (PointPropertyType) elements. "pos" elements are control points that are only part of this ring, "pointProperty" elements contain a point that may be referenced from other geometry elements or reference another point defined outside of this ring (reuse of existing points). 2. The "posList" element allows for a compact way to specifiy the coordinates of the control points, if all control points are in the same coordinate reference systems and belong to this ring only. The number of direct positions in the list must be at least four. Deprecated with GML version 3.1.0. Use "pointProperty" instead. Included for backwards compatibility with GML 3.0.0. Deprecated with GML version 3.1.0. Use "posList" instead. Deprecated with GML version 3.0 and included for backwards compatibility with GML 2. Use "pos" elements instead.