.. _accessors: +++++++++++++++++++++++++++++++++++++++++++++++ :mod:`tkp.accessors` -- Image container classes +++++++++++++++++++++++++++++++++++++++++++++++ Introduction ------------ The "accessors" system attempts to abstract away the physical image storage format from the library logic. The higher-level data access routines should not care whether the data is stored in a CASA table, or a FITS file, or in some other format: they should be coded against a uniform interface provided by the appropriate accessor. An accessor should subclass :class:`tkp.accessors.dataaccessor.DataAccessor`, which is an abstract base class. Accessors *must* conform to the DataAccessor interface by defining the relevant attributes (see the attributes listed under :class:`tkp.accessors.dataaccessor.DataAccessor` for full details). An accessor which provides all of these attributes is guaranteed to be usable with all core TraP functionality. In some cases, most notably :ref:`quality control `, specialized (eg, per-telescope) metadata may also be required. A further abstract base class should be constructed to define the interface required. For example, :class:`tkp.accessors.lofaraccessor.LofarAccessor` defines the following metadata which must be provided for LOFAR quality control: ``antenna_set`` Antenna set in use during observation. String; ``LBA_INNER``, ``LBA_OUTER``, ``LBA_SPARSE``, ``LBA`` or ``HBA`` ``ncore`` Number of core stations in use during observations constituting this image. Integer. ``nremote`` Number of remote stations in use during observations constituting this image. Integer. ``nintl`` Number of international stations in use during observations constituting this image. Integer. ``subbandwidth`` Width of a subband, in Hz. ``subbands`` Number of subbands. API Documentation ----------------- .. toctree:: api accessor_types