eXtensible Data Format (XDF) Homepage

XDF is a common scientific data format based on XML and general mathematical principles that can be used throughout the scientific disciplines. It includes these key features: hierarchical data structures, any dimensional arrays merged with coordinate information, high dimensional tables merged with field information, variable resolution, easy wrapping of existing data, user specified coordinate systems, searchable ASCII meta-data, and extensibility to new features/data formats.

Currently the XDF project supports 2 versions of XDF: a "stable" and "development" version. These versions are defined in their various DTDs with version XDF_017.dtd ("017") being the stable, older type of XDF and version XDF_018.dtd ("018") being our development standard. What this means is that few, if any, revisions occur in the 017 standard while 018 is currently undergoing significant and active "re-vision". We support both the stable and development versions in Java and Perl packages.

May 28 2003	Perl XDF Package	Development version 018 alpha 2 released!
May 28 2003	Perl XDF Package	"Final" version 017 released! (stable patchlevel 3)
		- Barring user patches, this is it for Perl work on 017.
June 13 2002	Java XDF Package	Stable version 017 candidate 1 released.
Dec 21 2001	Java XDF Package	Development version 018 released (alpha1).

General XDF Documentation and Samples

• The White paper on XDF (eXtensible Data Format) . (out of date but still informative)
• The eXtensible Data Format DTD (version 017). (stable DTD)
• The eXtensible Data Format DTD (version 018). (development DTD)
• A schematic of the XDF data model. Structures hold structures and arrays. Arrays hold data of any dimension (tabular or image) and axis or field information is always present.
• The XML Schema for version 0.17 of XDF (stable).
• The XML Schema for version 0.18 of XDF (beta).
  • A Schema diagram of XDF v0.18.
• The XML Schema for version 0.19 of XDF (experimental).
• A tree view of the XDF DTD
• XDF Sample Files

XDF Software

• The API of the Perl XDF Package
• The API of the Java XDF Package
• A UML diagram overviewing important objects in the XDF package and enlargement of that diagram showing objects within in the core XDF object

Talks and poster presentations that involve XDF

• Talk presented to the ESIP Federation Technical Workshop, An End-to-End XML Data Description: XDF
• Talk on XDF presented Feb 2002 at the NASA Science Data Processing Workshop, Creating an XML representation for science data formats with XDF: cases, design and implementation..
• Talk on XDF presented Nov. 8, 2000 at the NASA Science Data Processing Workshop, Introducing XDF - The eXtensible Data Format.

FITSML a Markup Languages that Inherit from XDF

• (FITSML) is an XML/XDF language rendition of the Flexible Image Transport System that is used primarily in astronomy.
  • The pre-draft FITSML DTD. Also, see the tree view of this markup language.
  • The XML Schema for FITSML.
  • An example FITSML file:vla_example.xml header information, without the data.