2012 Data Discussion
From canSAS
- The following is the agenda of work posted under business for canSAS-2012. Please add comments here:
- 1D Format
- agree a proposed foreign namespace extension of the current 1D standard (required to enable, for example, t-o-f instruments to store auxillary wavelength-dependent non-I(Q) data in the same output files)
- agree resultant changes to the schema/stylesheet
SMK - For clarity, this extension was proposed after adoption of the existing version of the standard. Ratification of
this extension at CanSAS-2012 would give facilities/software developers the necessary confidence to implement it.
SMK - This proposed extension would allow more-or-less any non-I(Q) data to be included in a CanSAS-1D data file under a
suitable foreign namespace. That is remarkable flexibility, and it does not require any significant revision
of the existing standard. However, it could be argued that certain types of non-I(Q) data are so integral to a SAS
experiment that they should instead be given explicit SASXML tags within the standard? Transmission data is a good
example of this: the existing standard explicitly includes a tag for the transmission value from a monochromatic
measurement (SASsample\transmission) but makes no provision for transmission values from white beam
measurements. The proposed foreign namespace extension will make such provision possible but only as an
extension, not as a formal part of the standard. Is that acceptable? The downside of explicitly adding new SASXML
tags to the existing standard is that it would require issuing a new version of the standard.
ARJN - I would recommend that during this meeting that the current format then be 'parked', the new 2D format
should be flexible enough to handle 1D and 2D data.
SMK - Agreed.
- 2D Format
- define minimum necessary for reduced data
- review previous discussions on 2D
- considerations specific to 2D reduced data
- consider forward looking issues such as
- grazing incidence
- event mode analysis
- suggest format framework (NeXus extension, canSAS 1D extension, other) with brief discussion of the reason for the choice (including options considered, pros and cons of each, and final weighing)
- Guide to how to make implementation easy.
- Create straw format suitable for test/demonstration use and convert some test data for such a demonstration.
- Provide a plan for presentation at SAS 2012
- A proposal for a 2D version of the canSAS 1D data format has been posted for discussion: 2D Data Format Proposal
- NeXus has a definition for multi-dimensional data:
- Ron Ghosh has laid out details of a proposal to use HDF5/Nexus : HDF5 Notes Ghosh
