IS:gradientChange

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gradientChange
 


Scheme description / Schemenbeschreibung / Description du schéma

Position of gradientChange in the XML-Tree / Position von gradientChange im XML-Baum / position de gradientChange dans l’aborescence XML

Multiplicity / Anzahl / Multiplicité

[0..∞]

Semantics / Bedeutung / Sémantique

A <gradientChange> defines in which position the gradient on a track changes.

Attributes of gradientChange / Attribute von gradientChange / Attributs de gradientChange

  • id: XML-file-wide unique, machine-interpretable identity, required for later referencing that element internally. For a detailed explanation see Dev:identities.
    XML-Datei-weit eindeutige, maschineninterpretierbare Identität, die für die spätere interne Referenzierung dieses Elements erforderlich ist. Für eine detaillierte Erklärung siehe Dev:identities.
  • code (introduced with version 2.1): Machine-interpretable string (e.g. an abbreviation) used for identification of the object across exchange partners, usecase specific uniqueness constraints may apply.
    Maschineninterpretierbare Zeichenkette (z.B. Abkürzung), die zur Identifizierung des Objekts auch bei Austauschpartnern verwendet wird, wobei spezifische Eindeutigkeitsbeschränkungen gelten können.
  • name: Established, human-readable short string, giving the object a name. Not intended for machine interpretation, please see our notice on human interpretable data fields.
    Etablierte, menschenlesbare kurze Zeichenkette, die das Objekt benennt. Nicht zur maschinellen Interpretation bestimmt, siehe Hinweise zu menschenlesbaren Datenfeldern.
  • description: Human-readable, more detailed description as addition to the name. It should give additional explanations or hints to the contents of this element. Not intended for machine interpretation, please see our notice on human interpretable data fields.
    Menschenlesbare, detailliertere Beschreibung als Ergänzung zu name. Sie soll zusätzliche Erläuterungen oder Hinweise auf den Inhalt dieses Elements geben. Nicht zur maschinellen Interpretation bestimmt, siehe Hinweise zu menschenlesbaren Datenfeldern.
  • xml:lang (introduced with version 2.1): This is a unique identifier of language. It uses basically the language standard IETF BCP 47 (external link) which may be different to ISO 639-1 (external link) or ISO 639-2 (external link). For mapping hints see relation to other standards (external link).
    This defines the language used for name and description. Use <additionalName> to provide a name and/or description in other languages.
  • pos: This is the position on a track defined as distance from its start (trackBegin) regardless the "absolute mileage" in @absPos.
    Das ist die Position des Elements auf einem Track i.S. der realen Entfernung zum trackBegin. Sie ist damit unabhängig von der mit absPos modellierten Strecken-Kilometrierung.
Note.png For an explanation of the differences between @pos and @absPos see <mileageChange>
  • absPos: This is the position on a track as absolute mileage/chainage.
    Das ist die Position des Elements im Referenzsystem der Strecken-Kilometrierung.
Note.png For an explanation of the differences between @pos and @absPos see <mileageChange>
  • absPosOffset (deprecated with version 2.1): The semantics of this attribute aren't very clear. It seems to be redundant to the definitions with mileageChanges in "overlapping regions".
  • dir: This defines the validity of gradientChange along the track. Possible values are:
  • up This denotes the direction from the <trackBegin> to the <trackEnd> (increasing relative position values).
  • down This goes opposite to up (decreasing relative position values).

Missinginformation.png In this article there is information missing with respect to the attribute semantics. Please help improving the railML® wiki by filling the gaps. Possibly, you will find further details on the discussion pageFerri Leberl (talk) 19:30, 15 January 2017 (CET)
  • slope
  • transitionLenght
  • transitionRadius

Syntactic Constraints / Syntaktische Beschränkungen / Contraintes syntactiques

  • id: xs:ID, required
    a string, starting with a letter (a..zA..Z) or an underscore (_),
    followed by a non-colonized and non-spaced string consisting of letters, digits, points (.), dashes (-) or underscores (_)
  • pos: tLengthM (xs:decimal, 6 fraction digits, length value measured in meter); required; must be greater than or equal to zero, less than or equal to the track's length
  • absPos: xs:decimal, 6 fraction digits, length value measured in meter; optional
  • absPosOffset: xs:decimal, 6 fraction digits, length value measured in meter; optional
  • dir: xs:string, generic type for more constrained direction statements: enumeration up, down; derived from tLaxDirection; optional
  • slope xs:decimal, 3 fraction digits, gradient (slope) value measured in per mille, mandatory
  • transitionLenght xs:decimal, 6 fraction digits, length value measured in meter, optional
  • transitionRadius xs:decimal, 6 fraction digits, radius value measured in meter, optional

Best practice & Examples / Empfohlene Anwendung & Beispiele / Bonnes pratiques & exemples

Handling of gradient changes in Norway

Illustration of the theoretical break point

In railML2.4nor/in the use in the Norwegian railway sector the <gradientChange> element describes a new slope value on a track, whenever this changes in comparison to the previous slope. The gradient must also be defined along the full extent of all tracks. Thus, it is mandatory to place a <gradientChange> at the beginning of a model or at a mileage direction change once for each direction. The gradient itself is given in the attribute @slope of <gradientChange>. It signifies the gradient of the slope in ‰ in track direction. Inclines are defined as positive slope values, declines as negative values. Vertical curves are not modelled. Thus, in the model, the slope is extended to a theoretical breakpoint. If it is necessary to distinguish between a high and low breakpoint, the reading software will have to deduct this from the data. The gradient can be microscopic or averaged macroscopic.

In railML2.4nor/in the use in the Norwegian railway sector the element <gradientChange> does not use the attribute @dir. The gradients are always valid in both directions, and the gradient change is - as all objects - defined in orientation of the track.

Code example
<gradientChanges>
   <gradientChange absPos="0.0" id="id56" pos="0.0" slope="0.0"/>
</gradientChanges>

Notes / Anmerkungen / Notes

General information on positioning

Positive pos values describe the distance from the track's begin. The track length is derived from the pos value in <trackEnd>.

The absolute mileage refered to by absPos is usually found on technical drawings of the track layout or on mileage posts next to the track.

Open issues / Offene Punkte/Pedenzen / Questions ouvertes

Not yet described. / Noch nicht beschrieben. / Pas encore décrit.