Talk:Data Formats Working Group

2007-12-18T00:11:27Z

137.157.8.253: /* In the Idata tag */

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==Which way to declare the units?==
--[[User:Jemian|Jemian]] 18:06, 17 December 2007 (EST)
Cast your vote by attaching initials to one of these three methods.

===In the Idata tag===
votes: PRJ, ARJN
<pre>
<SASdata>
<Idata>
<Q units="1/A"></Q>

<Qdev units="1/A"></Qdev>
<Idev units="1/cm"></Idev>
<Qfwhm units="1/A"></Qfwhm>
<Qmean units="1/A"></Qmean>
<ShadowFactor units="1/A"></ShadowFactor>
</Idata>
</SASdata>
</pre>

===As attributes of the SASdata tag===
votes:
<pre>
<SASdata
entries="Q:I:Qdev:Idev:Qfwhm:Qmean:ShadowFactor"
units="1/A:1/cm:1/A:1/cm:1/A:1/A:1/A">
<Idata>
<Q></Q>

<Qdev></Qdev>
<Idev></Idev>
<Qfwhm><! Qfwhm is optional ></Qfwhm>
<Qmean></Qmean>
<ShadowFactor></ShadowFactor>
</Idata>
</SASdata>
</pre>

===As axis declarations within the SASdata tag===
votes:
<pre>
<SASdata>
<axis name="Q" units="1/A" type="Idata" />
<axis name="I" units="1/cm" type="Idata" />
<axis name="Qdev" units="1/A" type="constant" >0.000085</axis>
<axis name="Idev" units="1/cm" type="Idata" />
<axis name="Qfwhm" units="1/A" type="constant" >0.000191</axis>
<axis name="Qmean" units="1/A" type="undefined" />
<axis name="ShadowFactor" units="1/A" type="undefined" />
<Idata>
<Q></Q>

<Qdev></Qdev>
<Idev></Idev>
<Qfwhm><! Qfwhm is optional ></Qfwhm>
<Qmean></Qmean>
<ShadowFactor></ShadowFactor>
</Idata>
</SASdata>
</pre>

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--[[User:Jemian|Jemian]] 12:01, 14 December 2007 (EST) items moved from main page
==Considerations==
* a key point of what we discussed at NIST:
namely that our goal is to agree a format which that whilst using as much best XML practice as is reasonable, leaves the file instantly human-readable, editable in the simplest of editors, and importable by simple text import filters in programs that don't recognise the XML.
* document what we decide
**1DWG will take care of documenting the format it defines.
*** make that definition with a schema (for absolute validation of any proposed XML file against the standard)
*** instructions on how to use that schema
*** XSL style sheets to present the XML contents in various forms (also serves as examples)
*** a couple of examples
*** maybe also some words.
** move some of this discussion to
*** discussion page
*** other wiki pages
*** /dev/null after its usefulness has been exhausted
* coordinate with other communities
** [http://www.nexusformat.org NeXus (http://www.nexusformat.org)]
** reflectivity
** powder diffraction
*** [http://www.xrdml.com XRDML (http://www.xrdml.com)]
* should we consider a file naming convention?
* should we consider a SAS scan naming convention?
** sequential run number from facility
** convention set by the detector software provider
* XML representation of the I vs. Q data
** tabular format
** vector format
* general XML coding style
** readability by humans
*** with lots of computer skills
*** with rudimentary computer skills
** readability by computers
*** standard XML libraries
*** generic visualization tools
*** common software such as MS Excel or Open Office or [ftp://ftp.ill.fr/pub/cs/rxml XMLPLO source code for windows/linux/OSX86]
*** A plugin for IGOR has been written, [http://www.igorexchange.com/project/XMLutils XMLutils.xop], that can handle XML data. The [[sasXML and IGOR]] page gives details on the IGOR code required to write the prototype sasXML file.
** availability of style sheets
* scalability of XML format to 2D data?
* What is required?
* What is optional?
* Use the same tags again in similar contexts
** X,Y pairs for example, whether detector position, beam center, sample position
{| width="100%" border="1" style="border:1px solid navy; border-collapse: collapse"
|-
! width="50%" | inconsistent
! width="50%" | consistent
|-
| <pre>
<beam_size axis="x" units="mm">12.00</beam_size>
<beam_size axis="y" units="mm">12.00</beam_size>
<x0 units="mm">322.64</x0>
<y0 units="mm">327.68</y0>
<pixel_x units="mm">5.00</pixel_x>
<pixel_y units="mm">5.00</pixel_y>
</pre>
| <pre>
<beam_size axis="x" units="mm">12.00</beam_size>
<beam_size axis="y" units="mm">12.00</beam_size>
<beam_center axis="x" units="mm">322.64</beam_center>
<beam_center axis="y" units="mm">327.68</beam_center>
<pixel_size axis="x" units="mm">5.00</pixel_size>
<pixel_size axis="y" units="mm">5.00</pixel_size>
</pre>
|}

===Points for Discussion===

*Do we want to advocate/recommend particular names for particular tags; eg, SASdata, SASsample, Idata, etc.?
** which ones?
* provide for (optional) inclusion of sample prep details
* provide for (optional) inclusion of other (non-SAS) data in the XML
* Need to allow for more than a single SAS data set in one .xml file

===Other Points===
* It's not clear how to specify that multiple runs were reduced together
**(AJJ) Assuming that those multiple runs were first stored as XML then referencing the individual files would give all that back information (a la Ghosh suggestion). At NIST we take absolute I vs Q files and combine them to produce an absolute I vs Q file thus that is reasonable here. What about elsewhere?
* How does one include the instrument information of the many runs that we used to make up the composite file
* If we have reduction information, then everything needs to be in there, i.e. the run numbers for the can, the standard, the uniform field, etc.
* Information on the averaging, is it radial, sector, rectangular, etc.

canSAS - User contributions [en]

Talk:Data Formats Working Group