Data Category array_intensities

General

Category name
array_intensities
Required in PDB entries
no
Category group membership
array_data_group
Used in current PDB entries
No

Category Relationship Diagrams

70
View full category relationship diagram including all dictionary data categories

Category Description

    Data items in the ARRAY_INTENSITIES category record the
    information required to recover the intensity data from
    the set of data values stored in the ARRAY_DATA category.

    The detector may have a complex relationship
    between the raw intensity values and the number of
    incident photons.  In most cases, the number stored
    in the final array will have a simple linear relationship
    to the actual number of incident photons, given by
    _array_intensities.gain.  If raw, uncorrected values
    are presented (e.g. for calibration experiments), the
    value of _array_intensities.linearity will be 'raw'
    and _array_intensities.gain will not be used.

NeXus Mapping Details

 

    _array_intensities.array_id ARRAYID
    _array_intensities.binary_id BINARYID
    _array_intensities.details DETAILS
    _array_intensities.gain GAIN
    _array_intensities.gain_esd GAINESD
    _array_intensities.linearity LINEARITY
    _array_intensities.offset OFFSET
    _array_intensities.scaling SCALING
    _array_intensities.overload OVERLOAD
    _array_intensities.undefined_value UNDEFVAL
    _array_intensities.underload UNDERLOAD
    _array_intensities.pixel_fast_bin_size FBINSIZE
    _array_intensities.pixel_slow_bin_size SBINSIZE
    _array_intensities.pixel_binning_method METHOD


    -->

      /entry:NXentry
        /data_ARRAYID_BINARYID:NXdata
          /data_ARRAYID_BINARYID
              @CBF_array_id="ARRAYID"
              @CBF_binary_id="BINARYID"
              @details="DETAILS"
              @gain=[GAIN]
              @gain_esd=[GAINESD]
              @linearity="LINEARITY"
              @offset=[OFFSET]
              @saturation_value=[OVERLOAD]
              @scaling_factor=[SCALING]
              @undefined_value=[UNDEFVAL]
              @underload_value=[UNDERLOAD]
              @CBF_array_intensities__pixel_fast_bin_size=[FBINSIZE]
              @CBF_array_intensities__pixel_slow_bin_size=[SBINSIZE]
              @CBF_array_intensities__pixel_binning_method="METHOD"
       /instrument:NXinstrument
         /DETECTORNAME:NXdetector_group
         /DETECTORELEMENTNAME:NXdetector
           /data_ARRAYID_BINARYID -->
                /entry/data_ARRAYID_BINARYID/data_ARRAYID_BINARYID

    The argument has been made that these attributes are not needed
    because NeXus files are supposed to have 'true values' stored.
    In many cases that is true and then none of these attributes
    are needed.  However, with some detectors and some experiments
    there are good technical and scientific reasons to bring in values
    that will need processing later to derive 'true values', and in
    those case some or all of these attributes will be needed.  They
    are provided for such cases.

    The same attributes could be used as fields in the case of a single
    data array, but in that case links for all the fields would be needed
    from NXdata to NXdetector, so it is preferable to use attributes even
    in the case of a single data array.  The reverse mapping will support
    both uses.

Category Example

 
        loop_
        _array_intensities.array_id
        _array_intensities.linearity
        _array_intensities.gain
        _array_intensities.overload
        _array_intensities.undefined_value
        _array_intensities.pixel_fast_bin_size
        _array_intensities.pixel_slow_bin_size
        _array_intensities.pixel_binning_method
        image_1   linear  1.2    655535   0   2   2    hardware