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Welcome to the XAS-Data-Interchange (XDI) wiki!

XDI is a proposed specification for describing a file containing a single scan of X-ray Absorption Spectroscopy (XAS) data. The specification is implemented as an augmented Backus-Naur Form (BNF) grammar. Any BNF-aware application can, therefore, use the grammar to parse and interpret an XDI-compliant data file.

The intention of XDI is to specify a mechanism for encoding metadata and data for a single-scan into a plain-text file. The metadata encoding allows an application (i.e. a data processing program, a web application, a data acquisition program, etc.) to extract useful information about a file, for instance the provenance (synchrotron and beamline) of the data or hints about how to combine data columns into useful spectra. The XDI specification also provides a mechanism for applications to encode additional metadata into a file.

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The XDI Specification

• XDISpec: This is the text of the XAS Data Interchange specification
• Dictionary-metadata: The dictionary of metadata for use with XDI
• RFCs and other specifications referenced in the specification:
  • RFC 2119.3, Key words for use in RFCs to Indicate Requirement Levels
  • RFC 52344, BNF for Syntax SpecificationsAugmented
  • RFC 3629, UTF-8, a transformation format of ISO 10646
  • RFC 822, Standard for ARPA Internet Text Messages
  • An explanation of the most relevant parts of ISO 8601, the time specification standard
• The XDI grammer, in a single file

Language implementations

Along with the formal BNF grammar, a complete specification document (written in LaTeX) is available. To make the specification widely useful and to encourage its adoption, ipmlemetations of the specification in many programming languages are provided, including:

• Perl: A complete implementation handling import and export. Implemented using Moose and Parse::RecDescent
• Python:
• Java:
• C:
• C++:
• Fortran:
• LabView:
• IDL: