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VOTable is an XML-based format for storage and transmission of
tabular data, endorsed by the
International Virtual Observatory
Alliance.
The DTD and documentation are available from
http://cdsweb.u-strasbg.fr/doc/VOTable/.
The current version of STIL supports version 1.0 of the format
(with a very few exceptions).
As with the other handlers tabular data can be read from and
written to VOTable documents using the generic facilities described
in section 3. However if you know you're going to be
dealing with VOTables the VOTable-specific parts of
the library can be used on their own; this may be more convenient and
it also allows access to some features specific to VOTables.
The VOTable functionality is provided in the package
uk.ac.starlink.votable
.
It has the following features:
- Reads all VOTable data formats
- Writes all VOTable data formats
- Full access to document structure
- Full handling of array types
- Flexible table output
- Hybrid (SAX/DOM) parsing
- Large tables
- Fast
- Offline parsing
- Resolution of relative URLs
- Sequential/random access to tabular data
- Best efforts parsing of non-conforming documents
Most of these are described in subsequent sections.
Many of them, particularly handling of BINARY and FITS format data,
are at time of writing not believed to be
available in any other VOTable libraries.
The following features of the VOTable format are not supported:
- ID/ref referencing of TABLE, FIELD elements
- VOTable 1.1 format GROUP elements
- Null value handling for numeric array data types in BINARY/FITS encodings
Additionally the handling of variable-length fields in BINARY streams
is done according to the VOTable 1.1 specification not the VOTable 1.0 one
(probably no table has ever been written using the latter,
so this is a Good Thing).
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Next: DATA Element Formats
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Previous: Table Joins
STIL - Starlink Tables Infrastructure Library
Starlink User Note
252
STIL web page:
http://www.starlink.ac.uk/stil/
Author email:
m.b.taylor@bristol.ac.uk
Starlink: http://www.starlink.ac.uk/