.. auto-generated by script ../../../../utils/nxdl2rst.py from the NXDL source ../../../../base_classes/NXsubentry.nxdl.xml

.. index::
    ! NXsubentry (base class)
    ! subentry (base class)
    see: subentry (base class); NXsubentry

.. _NXsubentry:

==========
NXsubentry
==========

**Status**:

  base class, extends :ref:`NXobject`, version 1.0

**Description**:

  ``NXsubentry`` is a base class virtually identical to ``NXentry``
  and is used as the (overlay) location for application definitions.
  Use a separate ``NXsubentry`` for each application definition.

  To use ``NXsubentry`` with a hypothetical application definition 
  called ``NXmyappdef``:

  * Create a group with attribute ``NX_class="NXsubentry"``
  * Within that group, create a field called ``definition="NXmyappdef"``.
  * There are two optional attributes of definition: ``version`` and ``URL``

  The intended use is to define application definitions for a 
  multi-technique ``NXentry``. Previously, an application definition 
  replaced ``NXentry`` with its own definition. 
  With the increasing popularity of instruments combining 
  multiple techniques for data collection (such as SAXS/WAXS instruments), 
  it was recognized the application definitions must be entered in the NeXus
  data file tree as children of ``NXentry``.

**Symbols**:

  No symbol table

**Groups cited**:
  :ref:`NXcharacterization`, :ref:`NXcollection`, :ref:`NXdata`, :ref:`NXinstrument`, :ref:`NXmonitor`, :ref:`NXnote`, :ref:`NXparameters`, :ref:`NXprocess`, :ref:`NXsample`, :ref:`NXuser`

.. index:: NXnote (base class); used in base class, NXcharacterization (base class); used in base class, NXuser (base class); used in base class, NXsample (base class); used in base class, NXinstrument (base class); used in base class, NXcollection (base class); used in base class, NXmonitor (base class); used in base class, NXdata (base class); used in base class, NXparameters (base class); used in base class, NXprocess (base class); used in base class

**Structure**:

  .. index:: IDF_Version (attribute)

  **@IDF_Version**: :ref:`NX_CHAR <NX_CHAR>`

    ISIS Muon IDF_Version

  .. index:: title (data field)

  **title**: :ref:`NX_CHAR <NX_CHAR>`

    Extended title for entry

  .. index:: experiment_identifier (data field)

  **experiment_identifier**: :ref:`NX_CHAR <NX_CHAR>`

    Unique identifier for the experiment, defined by
    the facility, possibly linked to the proposals

  .. index:: experiment_description (data field)

  **experiment_description**: :ref:`NX_CHAR <NX_CHAR>`

    Brief summary of the experiment, including key objectives.

  .. index:: collection_identifier (data field)

  **collection_identifier**: :ref:`NX_CHAR <NX_CHAR>`

    User or Data Acquisition defined group of NeXus files or NXentry

  .. index:: collection_description (data field)

  **collection_description**: :ref:`NX_CHAR <NX_CHAR>`

    Brief summary of the collection, including grouping criteria.

  .. index:: entry_identifier (data field)

  **entry_identifier**: :ref:`NX_CHAR <NX_CHAR>`

    unique identifier for the measurement, defined by the facility.

  .. index:: definition (data field)

  **definition**: :ref:`NX_CHAR <NX_CHAR>`

    Official NeXus NXDL schema to which this file conforms

    .. index:: version (attribute)

    **@version**: :ref:`NX_CHAR <NX_CHAR>`

      NXDL version number

    .. index:: URL (attribute)

    **@URL**: :ref:`NX_CHAR <NX_CHAR>`

      URL of NXDL file

  .. index:: definition_local (data field)

  **definition_local**: :ref:`NX_CHAR <NX_CHAR>`

    Local NXDL schema extended from the file
    specified in the ``definition`` field. 
    This contains any locally-defined,
    additional fields in the file.

    .. index:: version (attribute)

    **@version**: :ref:`NX_CHAR <NX_CHAR>`

      NXDL version number

    .. index:: URL (attribute)

    **@URL**: :ref:`NX_CHAR <NX_CHAR>`

      URL of NXDL file

  .. index:: start_time (data field)

  **start_time**: :ref:`NX_DATE_TIME <NX_DATE_TIME>`

    Starting time of measurement

  .. index:: end_time (data field)

  **end_time**: :ref:`NX_DATE_TIME <NX_DATE_TIME>`

    Ending time of measurement

  .. index:: duration (data field)

  **duration**: :ref:`NX_INT <NX_INT>` {units=\ :ref:`NX_TIME <NX_TIME>`}

    Duration of measurement

  .. index:: collection_time (data field)

  **collection_time**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_TIME <NX_TIME>`}

    Time transpired actually collecting data i.e. taking out time when collection was
    suspended due to e.g. temperature out of range

  .. index:: run_cycle (data field)

  **run_cycle**: :ref:`NX_CHAR <NX_CHAR>`

    Such as "2007-3". Some user facilities organize their beam time into run cycles.

  .. index:: program_name (data field)

  **program_name**: :ref:`NX_CHAR <NX_CHAR>`

    Name of program used to generate this file

    .. index:: version (attribute)

    **@version**: :ref:`NX_CHAR <NX_CHAR>`

      Program version number

    .. index:: configuration (attribute)

    **@configuration**: :ref:`NX_CHAR <NX_CHAR>`

      configuration of the program

  .. index:: revision (data field)

  **revision**: :ref:`NX_CHAR <NX_CHAR>`

    Revision id of the file due to re-calibration, reprocessing, new analysis, new
    instrument definition format, ...

    .. index:: comment (attribute)

    **@comment**: :ref:`NX_CHAR <NX_CHAR>`


  .. index:: pre_sample_flightpath (data field)

  **pre_sample_flightpath**: :ref:`NX_FLOAT <NX_FLOAT>` {units=\ :ref:`NX_LENGTH <NX_LENGTH>`}

    This is the flightpath before the sample position. This can be determined by a chopper,
    by the moderator or the source itself. In other words: it the distance to the component
    which gives the T0 signal to the detector electronics. If another component in the
    NXinstrument hierarchy provides this information, this should be a link.

  **experiment_documentation**: :ref:`NXnote`

    Description of the full experiment (document in pdf, latex, ...)

  **notes**: :ref:`NXnote`

    Notes describing entry

  **thumbnail**: :ref:`NXnote`

    A small image that is representative of the entry. An example of this is a 640x480
    jpeg image automatically produced by a low resolution plot of the NXdata.

    .. index:: mime_type (attribute)

    **@mime_type**: :ref:`NX_CHAR <NX_CHAR>`

      The value should be an ``image/*``

      Obligatory value:  ``image/*``

  **(characterization)**: :ref:`NXcharacterization`


  **(user)**: :ref:`NXuser`


  **(sample)**: :ref:`NXsample`


  **(instrument)**: :ref:`NXinstrument`


  **(collection)**: :ref:`NXcollection`


  **(monitor)**: :ref:`NXmonitor`


  **(data)**: :ref:`NXdata`


  **(parameters)**: :ref:`NXparameters`


  **(process)**: :ref:`NXprocess`


**Source**:
  Automatically generated from https://github.com/nexusformat/definitions/blob/master/base_classes/NXsubentry.nxdl.xml