GML is an OGC Standard.
Copyright (c) 2001,2005,2010 Open Geospatial Consortium.
To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ .
Properties
attribute form default:
unqualified
element form default:
qualified
version:
3.1.1.2
Element gml:curveMember
Namespace
http://www.opengis.net/gml
Annotations
This property element either references a curve via the XLink-attributes or contains the curve element. A curve element is
any element which is substitutable for "_Curve".
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.
<element name="curveMember" type="gml:CurvePropertyType"><annotation><documentation>This property element either references a curve via the XLink-attributes or contains the curve element. A curve element is any element which is substitutable for "_Curve".</documentation></annotation></element>
Element gml:_Solid
Namespace
http://www.opengis.net/gml
Annotations
The "_Solid" element is the abstract head of the substituition group for all (continuous) solid elements.
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.
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This identifer is superceded by "gml:id" inherited from AbstractGMLType.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.
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.
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.
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.
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.
Source
<element name="_Solid" type="gml:AbstractSolidType" abstract="true" substitutionGroup="gml:_GeometricPrimitive"><annotation><documentation>The "_Solid" element is the abstract head of the substituition group for all (continuous) solid elements.</documentation></annotation></element>
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.
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.
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.
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.
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.
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.
<element name="segments" type="gml:CurveSegmentArrayPropertyType"><annotation><documentation>This property element contains a list of curve segments. The order of the elements is significant and shall be preserved when processing the array.</documentation></annotation></element>
Element gml:_CurveSegment
Namespace
http://www.opengis.net/gml
Annotations
The "_CurveSegment" element is the abstract head of the substituition group for all curve segment elements, i.e. continuous
segments of the same interpolation mechanism.
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
Source
<element name="_CurveSegment" type="gml:AbstractCurveSegmentType" abstract="true"><annotation><documentation>The "_CurveSegment" element is the abstract head of the substituition group for all curve segment elements, i.e. continuous segments of the same interpolation mechanism.</documentation></annotation></element>
Element gml:baseCurve
Namespace
http://www.opengis.net/gml
Annotations
This property element either references a curve via the XLink-attributes or contains the curve element. A curve element is
any element which is substitutable for "_Curve".
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.
<element name="baseCurve" type="gml:CurvePropertyType"><annotation><appinfo><sch:pattern name="Check either href or content not both"><sch:rule context="gml:baseCurve"><sch:extends rule="hrefOrContent"/></sch:rule></sch:pattern></appinfo><documentation>This property element either references a curve via the XLink-attributes or contains the curve element. A curve element is any element which is substitutable for "_Curve".</documentation></annotation></element>
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.
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.
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.
If the orientation is "+", then the OrientableCurve is identical to the baseCurve. If the orientation is "-", then the OrientableCurve
is related to another _Curve with a parameterization that reverses the sense of the curve traversal. "+" is the default value.
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.
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.
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.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For a LineStringSegment the
interpolation is fixed as "linear".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcString the interpolation
is fixed as "circularArc3Points".
The number of arcs in the arc string can be explicitly stated in this attribute. The number of control points in the arc string
must be 2 * numArc + 1.
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcString the interpolation
is fixed as "circularArc3Points".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcString the interpolation
is fixed as "circularArc3Points".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcStringByBulge the
interpolation is fixed as "circularArc2PointWithBulge".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The bulge controls the offset of each arc's midpoint. The "bulge" is the real number multiplier for the normal that determines
the offset direction of the midpoint of each arc. The length of the bulge sequence is exactly 1 less than the length of the
control point array, since a bulge is needed for each pair of adjacent points in the control point array. The bulge is not
given by a distance, since it is simply a multiplier for the normal.
The midpoint of the resulting arc is given by: midPoint = ((startPoint + endPoint)/2.0) + bulge*normal
Diagram
Type
double
Properties
content:
simple
maxOccurs:
unbounded
Source
<element name="bulge" type="double" maxOccurs="unbounded"><annotation><documentation>The bulge controls the offset of each arc's midpoint. The "bulge" is the real number multiplier for the normal that determines the offset direction of the midpoint of each arc. The length of the bulge sequence is exactly 1 less than the length of the control point array, since a bulge is needed for each pair of adjacent points in the control point array. The bulge is not given by a distance, since it is simply a multiplier for the normal.
The midpoint of the resulting arc is given by: midPoint = ((startPoint + endPoint)/2.0) + bulge*normal</documentation></annotation></element>
The attribute "normal" is a vector normal (perpendicular) to the chord of the arc, the line joining the first and last
point of the arc. In a 2D coordinate system, there are only two possible directions for the normal, and it is often given
as a signed real, indicating its length, with a positive sign indicating a left turn angle from the chord line, and a negative
sign indicating a right turn from the chord. In 3D, the normal determines the plane of the arc, along with the start and endPoint
of the arc.
The normal is usually a unit vector, but this is not absolutely necessary. If the normal is a zero vector, the geometric object
becomes equivalent to the straight line between the two end points. The length of the normal sequence is exactly the same
as for the bulge sequence, 1 less than the control point sequence length.
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.
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.
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.
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.
Source
<element name="normal" type="gml:VectorType" maxOccurs="unbounded"><annotation><documentation>The attribute "normal" is a vector normal (perpendicular) to the chord of the arc, the line joining the first and last
point of the arc. In a 2D coordinate system, there are only two possible directions for the normal, and it is often given as a signed real, indicating its length, with a positive sign indicating a left turn angle from the chord line, and a negative sign indicating a right turn from the chord. In 3D, the normal determines the plane of the arc, along with the start and endPoint of the arc.
The normal is usually a unit vector, but this is not absolutely necessary. If the normal is a zero vector, the geometric object becomes equivalent to the straight line between the two end points. The length of the normal sequence is exactly the same as for the bulge sequence, 1 less than the control point sequence length.</documentation></annotation></element>
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcStringByBulge the
interpolation is fixed as "circularArc2PointWithBulge".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The bulge controls the offset of each arc's midpoint. The "bulge" is the real number multiplier for the normal that determines
the offset direction of the midpoint of each arc. The length of the bulge sequence is exactly 1 less than the length of the
control point array, since a bulge is needed for each pair of adjacent points in the control point array. The bulge is not
given by a distance, since it is simply a multiplier for the normal.
The midpoint of the resulting arc is given by: midPoint = ((startPoint + endPoint)/2.0) + bulge*normal
Diagram
Type
double
Properties
content:
simple
Source
<element name="bulge" type="double"><annotation><documentation>The bulge controls the offset of each arc's midpoint. The "bulge" is the real number multiplier for the normal that determines the offset direction of the midpoint of each arc. The length of the bulge sequence is exactly 1 less than the length of the control point array, since a bulge is needed for each pair of adjacent points in the control point array. The bulge is not given by a distance, since it is simply a multiplier for the normal.
The midpoint of the resulting arc is given by: midPoint = ((startPoint + endPoint)/2.0) + bulge*normal</documentation></annotation></element>
The attribute "normal" is a vector normal (perpendicular) to the chord of the arc, the line joining the first and last
point of the arc. In a 2D coordinate system, there are only two possible directions for the normal, and it is often given
as a signed real, indicating its length, with a positive sign indicating a left turn angle from the chord line, and a negative
sign indicating a right turn from the chord. In 3D, the normal determines the plane of the arc, along with the start and endPoint
of the arc.
The normal is usually a unit vector, but this is not absolutely necessary. If the normal is a zero vector, the geometric object
becomes equivalent to the straight line between the two end points. The length of the normal sequence is exactly the same
as for the bulge sequence, 1 less than the control point sequence length.
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.
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.
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.
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.
Source
<element name="normal" type="gml:VectorType"><annotation><documentation>The attribute "normal" is a vector normal (perpendicular) to the chord of the arc, the line joining the first and last
point of the arc. In a 2D coordinate system, there are only two possible directions for the normal, and it is often given as a signed real, indicating its length, with a positive sign indicating a left turn angle from the chord line, and a negative sign indicating a right turn from the chord. In 3D, the normal determines the plane of the arc, along with the start and endPoint of the arc.
The normal is usually a unit vector, but this is not absolutely necessary. If the normal is a zero vector, the geometric object becomes equivalent to the straight line between the two end points. The length of the normal sequence is exactly the same as for the bulge sequence, 1 less than the control point sequence length.</documentation></annotation></element>
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcByCenterPoint the
interpolation is fixed as "circularArcCenterPointWithRadius".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
<element name="startAngle" type="gml:AngleType" minOccurs="0"><annotation><documentation>The bearing of the arc at the start.</documentation></annotation></element>
<element name="endAngle" type="gml:AngleType" minOccurs="0"><annotation><documentation>The bearing of the arc at the end.</documentation></annotation></element>
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For an ArcByCenterPoint the
interpolation is fixed as "circularArcCenterPointWithRadius".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
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.
<element name="offsetBase" type="gml:CurvePropertyType"><annotation><documentation>offsetBase is a reference to thecurve from which this
curve is define as an offset.</documentation></annotation></element>
distance is the distance at which the
offset curve is generated from the basis curve. In 2D systems, positive distances
are to be to the left of the basis curve, and the negative distances are to be to the
right of the basis curve.
<element name="distance" type="gml:LengthType"><annotation><documentation>distance is the distance at which the
offset curve is generated from the basis curve. In 2D systems, positive distances
are to be to the left of the basis curve, and the negative distances are to be to the
right of the basis curve.</documentation></annotation></element>
refDistance is used to define the vector
direction of the offset curve from the basis curve. It can
be omitted in the 2D case, where the distance can be
positive or negative. In that case, distance defines left
side (positive distance) or right side (negative distance)
with respect to the tangent to the basis curve.
In 3D the basis curve shall have a well defined tangent
direction for every point. The offset curve at any point
in 3D, the basis curve shall have a well-defined tangent
direction for every point. The offset curve at any point
(parameter) on the basis curve c is in the direction
- - - -
s = v x t where v = c.refDirection()
and
-
t = c.tangent()
-
For the offset direction to be well-defined, v shall not
on any point of the curve be in the same, or opposite,
direction as
-
t.
The default value of the refDirection shall be the local
co-ordinate axis vector for elevation, which indicates up for
the curve in a geographic sense.
NOTE! If the refDirection is the positive tangent to the
local elevation axis ("points upward"), then the offset
vector points to the left of the curve when viewed from
above.
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.
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.
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.
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.
Source
<element name="refDirection" type="gml:VectorType" minOccurs="0"><annotation><documentation>refDistance is used to define the vector
direction of the offset curve from the basis curve. It can
be omitted in the 2D case, where the distance can be
positive or negative. In that case, distance defines left
side (positive distance) or right side (negative distance)
with respect to the tangent to the basis curve.
In 3D the basis curve shall have a well defined tangent
direction for every point. The offset curve at any point
in 3D, the basis curve shall have a well-defined tangent
direction for every point. The offset curve at any point
(parameter) on the basis curve c is in the direction
- - - -
s = v x t where v = c.refDirection()
and
-
t = c.tangent()
-
For the offset direction to be well-defined, v shall not
on any point of the curve be in the same, or opposite,
direction as
-
t.
The default value of the refDirection shall be the local
co-ordinate axis vector for elevation, which indicates up for
the curve in a geographic sense.
NOTE! If the refDirection is the positive tangent to the
local elevation axis ("points upward"), then the offset
vector points to the left of the curve when viewed from
above.</documentation></annotation></element>
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.
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.
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.
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.
Source
<element name="location" type="gml:DirectPositionType"><annotation><documentation>The location property gives
the target of the parameter space origin. This is the vector
(x0, y0, z0) in the formulae above.</documentation></annotation></element>
The attribute refDirection gives the
target directions for the co-ordinate basis vectors of the
parameter space. These are the columns of the matrix in the
formulae given above. The number of directions given shall be
inDimension. The dimension of the directions shall be
outDimension.
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.
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.
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.
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.
Source
<element name="refDirection" type="gml:VectorType" maxOccurs="unbounded"><annotation><documentation>The attribute refDirection gives the
target directions for the co-ordinate basis vectors of the
parameter space. These are the columns of the matrix in the
formulae given above. The number of directions given shall be
inDimension. The dimension of the directions shall be
outDimension.</documentation></annotation></element>
<element name="inDimension" type="positiveInteger"><annotation><documentation>Dimension of the constructive parameter
space.</documentation></annotation></element>
<element name="outDimension" type="positiveInteger"><annotation><documentation>Dimension of the co-ordinate space.</documentation></annotation></element>
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
<element name="refLocation"><complexType><sequence><element ref="gml:AffinePlacement"><annotation><documentation>The "refLocation" is an affine mapping
that places the curve defined by the Fresnel Integrals
into the co-ordinate reference system of this object.</documentation></annotation></element></sequence></complexType></element>
The element gives the value for the
constant in the Fresnel's integrals.
Diagram
Type
decimal
Properties
content:
simple
Source
<element name="scaleFactor" type="decimal"><annotation><documentation>The element gives the value for the
constant in the Fresnel's integrals.</documentation></annotation></element>
The startParameter is the arc length
distance from the inflection point that will be the start
point for this curve segment. This shall be lower limit
used in the Fresnel integral and is the value of the
constructive parameter of this curve segment at its start
point. The startParameter can either be positive or
negative.
NOTE! If 0.0 (zero), lies between the startParameter and
the endParameter of the clothoid, then the curve goes
through the clothoid's inflection point, and the direction
of its radius of curvature, given by the second
derivative vector, changes sides with respect to the
tangent vector. The term length distance for the
Diagram
Type
double
Properties
content:
simple
Source
<element name="startParameter" type="double"><annotation><documentation>The startParameter is the arc length
distance from the inflection point that will be the start
point for this curve segment. This shall be lower limit
used in the Fresnel integral and is the value of the
constructive parameter of this curve segment at its start
point. The startParameter can either be positive or
negative.
NOTE! If 0.0 (zero), lies between the startParameter and
the endParameter of the clothoid, then the curve goes
through the clothoid's inflection point, and the direction
of its radius of curvature, given by the second
derivative vector, changes sides with respect to the
tangent vector. The term length distance for the</documentation></annotation></element>
The endParameter is the arc length
distance from the inflection point that will be the end
point for this curve segment. This shall be upper limit
used in the Fresnel integral and is the value of the
constructive parameter of this curve segment at its
start point. The startParameter can either be positive
or negative.
Diagram
Type
double
Properties
content:
simple
Source
<element name="endParameter" type="double"><annotation><documentation>The endParameter is the arc length
distance from the inflection point that will be the end
point for this curve segment. This shall be upper limit
used in the Fresnel integral and is the value of the
constructive parameter of this curve segment at its
start point. The startParameter can either be positive
or negative.</documentation></annotation></element>
The attribute "interpolation" specifies the
curve interpolation mechanism used for this segment. This
mechanism uses the control points and control parameters to
determine the position of this curve segment. For an
GeodesicString the interpolation is fixed as "geodesic".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the
curve interpolation mechanism used for this segment. This
mechanism uses the control points and control parameters to
determine the position of this curve segment. For an
GeodesicString the interpolation is fixed as "geodesic".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For a CubicSpline the interpolation
is fixed as "cubicSpline".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
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.
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.
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.
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.
Source
<element name="vectorAtStart" type="gml:VectorType"><annotation><documentation>"vectorAtStart" is the unit tangent vector at the start point of the spline.</documentation></annotation></element>
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.
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.
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.
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.
Source
<element name="vectorAtEnd" type="gml:VectorType"><annotation><documentation>"vectorAtEnd" is the unit tangent vector at the end point of the spline.</documentation></annotation></element>
The property "value" is the value of the parameter at the knot of the spline. The sequence of knots shall be a non-decreasing
sequence. That is, each knot's value in the sequence shall be equal to or greater than the previous knot's value. The use
of equal consecutive knots is normally handled using the multiplicity.
Diagram
Type
double
Properties
content:
simple
Source
<element name="value" type="double"><annotation><documentation>The property "value" is the value of the parameter at the knot of the spline. The sequence of knots shall be a non-decreasing sequence. That is, each knot's value in the sequence shall be equal to or greater than the previous knot's value. The use of equal consecutive knots is normally handled using the multiplicity.</documentation></annotation></element>
The property "multiplicity" is the multiplicity of this knot used in the definition of the spline (with the same weight).
Diagram
Type
nonNegativeInteger
Properties
content:
simple
Source
<element name="multiplicity" type="nonNegativeInteger"><annotation><documentation>The property "multiplicity" is the multiplicity of this knot used in the definition of the spline (with the same weight).</documentation></annotation></element>
The property "weight" is the value of the averaging weight used for this knot of the spline.
Diagram
Type
double
Properties
content:
simple
Source
<element name="weight" type="double"><annotation><documentation>The property "weight" is the value of the averaging weight used for this knot of the spline.</documentation></annotation></element>
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For a BSpline the interpolation
can be either "polynomialSpline" or "rationalSpline", default is "polynomialSpline".
The attribute "knotType" gives the type of knot distribution used in defining this spline. This is for information only
and is set according to the different construction-functions.
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "degree" shall be the degree of the polynomial used for interpolation in this spline.
Diagram
Type
nonNegativeInteger
Properties
content:
simple
Source
<element name="degree" type="nonNegativeInteger"><annotation><documentation>The attribute "degree" shall be the degree of the polynomial used for interpolation in this spline.</documentation></annotation></element>
<element name="knot" type="gml:KnotPropertyType" minOccurs="2" maxOccurs="unbounded"><annotation><documentation>The property "knot" shall be the sequence of distinct knots used to define the spline basis functions.</documentation></annotation></element>
The attribute "interpolation" specifies the curve interpolation mechanism used for this segment. This mechanism
uses the control points and control parameters to determine the position of this curve segment. For a Bezier the interpolation
is fixed as "polynomialSpline".
The attribute "numDerivativesInterior" specifies the type of continuity that is guaranteed interior to the curve. The default
value of "0" means simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0
" in mathematical texts. A value of 1 means that the function and its first derivative are continuous at the appropriate end
point: "C 1 " continuity. A value of "n" for any integer means the function and its first n derivatives are continuous: "C
n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtEnd" specifies the type of continuity between this curve segment and its successor. If this
is the last curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means simple
continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts. A
value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "numDerivativesAtStart" specifies the type of continuity between this curve segment and its predecessor. If
this is the first curve segment in the curve, one of these values, as appropriate, is ignored. The default value of "0" means
simple continuity, which is a mandatory minimum level of continuity. This level is referred to as "C 0 " in mathematical texts.
A value of 1 means that the function and its first derivative are continuous at the appropriate end point: "C 1 " continuity.
A value of "n" for any integer means the function and its first n derivatives are continuous: "C n " continuity.
NOTE: Use of these values is only appropriate when the basic curve definition is an underdetermined system. For example, line
string segments cannot support continuity above C 0 , since there is no spare control parameter to adjust the incoming angle
at the end points of the segment. Spline functions on the other hand often have extra degrees of freedom on end segments that
allow them to adjust the values of the derivatives to support C 1 or higher continuity.
The attribute "degree" shall be the degree of the polynomial used for interpolation in this spline.
Diagram
Type
nonNegativeInteger
Properties
content:
simple
Source
<element name="degree" type="nonNegativeInteger"><annotation><documentation>The attribute "degree" shall be the degree of the polynomial used for interpolation in this spline.</documentation></annotation></element>
<element name="knot" type="gml:KnotPropertyType" minOccurs="2" maxOccurs="2"><annotation><documentation>The property "knot" shall be the sequence of distinct knots used to define the spline basis functions.</documentation></annotation></element>
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.
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.
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.
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.
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.
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.
<element name="patches" type="gml:SurfacePatchArrayPropertyType"><annotation><documentation>This property element contains a list of surface patches. The order of the elements is significant and shall be preserved when processing the array.</documentation></annotation></element>
Element gml:_SurfacePatch
Namespace
http://www.opengis.net/gml
Annotations
The "_SurfacePatch" element is the abstract head of the substituition group for all surface pach elements describing a continuous
portion of a surface.
<element name="_SurfacePatch" type="gml:AbstractSurfacePatchType" abstract="true"><annotation><documentation>The "_SurfacePatch" element is the abstract head of the substituition group for all surface pach elements describing a continuous portion of a surface.</documentation></annotation></element>
Element gml:baseSurface
Namespace
http://www.opengis.net/gml
Annotations
This property element either references a surface via the XLink-attributes or contains the surface element. A surface element
is any element which is substitutable for "_Surface".
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.
<element name="baseSurface" type="gml:SurfacePropertyType"><annotation><appinfo><sch:pattern name="Check either href or content not both"><sch:rule context="gml:baseSurface"><sch:extends rule="hrefOrContent"/></sch:rule></sch:pattern></appinfo><documentation>This property element either references a surface via the XLink-attributes or contains the surface element. A surface element is any element which is substitutable for "_Surface".</documentation></annotation></element>
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.
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.
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.
If the orientation is "+", then the OrientableSurface is identical to the baseSurface. If the orientation is "-", then the
OrientableSurface is a reference to a Surface with an up-normal that reverses the direction for this OrientableSurface, the
sense of "the top of the surface". "+" is the default value.
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.
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.
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.
The attribute "interpolation" specifies the interpolation mechanism used for this surface patch. Currently only planar surface
patches are defined in GML 3, the attribute is fixed to "planar", i.e. the interpolation method shall return points on a single
plane. The boundary of the patch shall be contained within that plane.
The attribute "interpolation" specifies the interpolation mechanism used for this surface patch. Currently only planar surface
patches are defined in GML 3, the attribute is fixed to "planar", i.e. the interpolation method shall return points on a single
plane. The boundary of the patch shall be contained within that plane.
The attribute "interpolation" specifies the interpolation mechanism used for this surface patch. Currently only planar surface
patches are defined in GML 3, the attribute is fixed to "planar", i.e. the interpolation method shall return points on a single
plane. The boundary of the patch shall be contained within that plane.
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.
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.
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.
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.
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.
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.
