.. auto-generated by dev_tools.docs.nxdl from the NXDL source base_classes/NXorientation.nxdl.xml -- DO NOT EDIT

.. index::
    ! NXorientation (base class)
    ! orientation (base class)
    see: orientation (base class); NXorientation

.. _NXorientation:

=============
NXorientation
=============

..
    Contributors List

    .. |contrib_name| replace:: Pete R Jemian|prjemian|https://avatars.githubusercontent.com/u/2279984?v=4|2022-01-28

    .. |contrib_name| replace:: Peter Chang|PeterC-DLS|https://avatars.githubusercontent.com/u/1381719?v=4|2020-10-20

    .. |contrib_name| replace:: Tobias Richter|zjttoefs|https://avatars.githubusercontent.com/u/856440?v=4|2018-05-15

**Status**:

  base class, extends :ref:`NXobject`

**Description**:

  .. collapse:: legacy class - recommend to use :ref:`NXtransformations` now ...

      legacy class - recommend to use :ref:`NXtransformations` now

      Description for a general orientation of a component - used by :ref:`NXgeometry`

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXgeometry`

.. index:: NXgeometry (base class); used in base class

**Structure**:

  .. _/NXorientation@default-attribute:

  .. index:: default (file attribute)

  **@default**: (optional) :ref:`NX_CHAR <NX_CHAR>` 

    .. collapse:: Declares which child group contains a path leading  ...

        .. index:: plotting

        Declares which child group contains a path leading 
        to a :ref:`NXdata` group.

        It is recommended (as of NIAC2014) to use this attribute
        to help define the path to the default dataset to be plotted.
        See https://www.nexusformat.org/2014_How_to_find_default_data.html
        for a summary of the discussion.

  .. _/NXorientation/value-field:

  .. index:: value (field)

  **value**: (optional) :ref:`NX_FLOAT <NX_FLOAT>` (Rank: 2, Dimensions: [numobj, 6]) {units=\ :ref:`NX_UNITLESS <NX_UNITLESS>`} 

    .. collapse:: The orientation information is stored as direction cosines. The direction cosi ...

        The orientation information is stored as direction cosines. The direction cosines will
        be between the local coordinate directions and the reference directions (to origin or
        relative NXgeometry). Calling the local unit vectors (x',y',z') and the reference unit
        vectors (x,y,z) the six numbers will be [x' dot x, x' dot y, x' dot z, y' dot x, y' dot
        y, y' dot z] where "dot" is the scalar dot product (cosine of the angle between the unit
        vectors). The unit vectors in both the local and reference coordinates are right-handed
        and orthonormal.

        The pair of groups NXtranslation and NXorientation together
        describe the position of a component.

  .. _/NXorientation/GEOMETRY-group:

  **GEOMETRY**: (optional) :ref:`NXgeometry` 

    Link to another object if we are using relative positioning, else absent


Hypertext Anchors
-----------------

List of hypertext anchors for all groups, fields,
attributes, and links defined in this class.


* :ref:`/NXorientation/GEOMETRY-group </NXorientation/GEOMETRY-group>`
* :ref:`/NXorientation/value-field </NXorientation/value-field>`
* :ref:`/NXorientation@default-attribute </NXorientation@default-attribute>`

**NXDL Source**:
  https://github.com/nexusformat/definitions/blob/main/base_classes/NXorientation.nxdl.xml