[pdDMG] DDLm pdCIF Issue 1: could detector and 2 theta offset be looped together in pd_calib?

[James Hester]

The latest version available on github (HTML:
http://comcifs.github.io/cif_pow.dic.html, raw text
https://github.com/COMCIFS/cif_core/blob/cif2-conversion/cif_pow.dic)
implements this change (optionally including a detector_id in the 2 theta
offset loop).  I will present this dictionar to COMCIFS next week for a
3-week review unless I hear otherwise from this group.

James.

On 3 November 2016 at 16:59, James Hester <jamesrhester at gmail.com> wrote:

> (Another missed message from Brian below)
>
> The situation with Brian's single Huber seems to be described well with a
> 'correction against 2 theta' table using _pd_calib_offset_* (
> http://comcifs.github.io/cif_pow.dic.html#PD_CALIB_OFFSET).  But you have
> reminded me that our PD neutron detector here consists of 128 tubes, all of
> which have their own 2 theta offset correction.  This is all absorbed
> during the data reduction but would be nice to capture nevertheless in the
> output pdCIF file.
>
> What I suggest we then do is add a pd_calib_offset.detector_id dataname
> for the situations in which there is a separate offset per detector. This
> dataname would take a default value in the case of a single detector and so
> could be left out of the _pd_calib_offset loop in that case.
>
> James.
>
>
> On 3 November 2016 at 16:15, Toby, Brian H. <toby at anl.gov> wrote:
>
>> one more, from yesterday
>>
>> Begin forwarded message:
>>
>> *From: *Brian Toby <toby at anl.gov>
>> *Subject: **Re: [pdDMG] DDLm pdCIF Issue 1: could detector and 2 theta
>> offset be looped together in pd_calib?*
>> *Date: *November 1, 2016 at 10:52:20 AM CDT
>> *To: *Distribution list of the IUCr COMCIFS Powder Diffraction
>> Dictionary Maintenance Group <pddmg at iucr.org>
>>
>> I put this aside for more thought originally, but I am not sure if that
>> moment will arrive, so let me provide a few (perhaps random) comments.
>>
>> One concern here is that it is common with strip and area detectors that
>> one often collects data at different two-theta settings due to gaps in the
>> arrays. I will skip the self-citation, but I have worked on a detector
>> where the CCD readout is synchronized to the two-theta sweep. One would
>> probably not try to handle raw data from that in pdCIF, but I could
>> certainly imagine having Mythen data collected at several different 2theta
>> settings. I guess a separate block for each could be a solution, if we so
>> choose.
>>
>> I think that I also considered the case where the 2-theta offset could
>> vary with 2theta. At 11-BM we do apply corrections as a function of 2-theta
>> since we can see that the Huber deviates from ideal.
>>
>> Brian
>>
>>
>> On Oct 31, 2016, at 10:28 PM, James Hester <jamesrhester at gmail.com>
>> wrote:
>>
>> There having been no response to this, I will assume that there is
>> limited to no demand for a multi-detector+multi-offset capability and leave
>> the current powCIF draft as is.
>>
>> James.
>>
>> On 24 October 2016 at 11:23, James Hester <jamesrhester at gmail.com> wrote:
>>
>>> In DDL1, items in the pd_calib category can vary by detector ("loops may
>>> be used for calibration information that differs by detector channel").
>>> Similarly, 2theta offset values can be looped where the offset varies by
>>> point.  While this is fine, it is not clear if we wish the pd dictionary to
>>> cover a situation where both detector and 2 theta offset vary, that is, for
>>> each detector in a multi-detector setup the 2 theta offset can take
>>> multiple values for different points collected by that detector.  Has
>>> anyone encountered such a situation?
>>>
>>> If the situation is rare, but conceivable, we can create a separate
>>> 'extension dictionary' which covers this case, but mainstream software is
>>> protected from misinterpreting loops (this is a new feature).
>>>
>>> James.
>>>
>>> --
>>> T +61 (02) 9717 9907
>>> F +61 (02) 9717 3145
>>> M +61 (04) 0249 4148
>>>
>>
>>
>>
>> --
>> T +61 (02) 9717 9907
>> F +61 (02) 9717 3145
>> M +61 (04) 0249 4148
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>>
>> ********************************************************************
>> Brian H. Toby, Ph.D.                            office: 630-252-5488
>> Advanced Photon Source Chief Computational Scientist
>> Senior Physicist/Computational X-ray Science Group Leader
>> 9700 S. Cass Ave, Bldg. 401/B4192                 cell: 630-327-8426
>> Argonne National Laboratory
>> Argonne, IL 60439-4856         e-mail: brian dot toby at anl dot gov
>> ********************************************************************
>> "We will restore science to its rightful place, and wield technology's
>> wonders... We will harness the sun and the winds and the soil to fuel our
>> cars and run our factories...  All this we can do. All this we will do."
>>
>>
>> ********************************************************************
>> Brian H. Toby, Ph.D.                            office: 630-252-5488
>> Advanced Photon Source Chief Computational Scientist
>> Senior Physicist/Computational X-ray Science Group Leader
>> 9700 S. Cass Ave, Bldg. 401/B4192                 cell: 630-327-8426
>> Argonne National Laboratory
>> Argonne, IL 60439-4856         e-mail: brian dot toby at anl dot gov
>> ********************************************************************
>> "We will restore science to its rightful place, and wield technology's
>> wonders... We will harness the sun and the winds and the soil to fuel our
>> cars and run our factories...  All this we can do. All this we will do."
>>
>>
>
>
> --
> T +61 (02) 9717 9907
> F +61 (02) 9717 3145
> M +61 (04) 0249 4148
>



-- 
T +61 (02) 9717 9907
F +61 (02) 9717 3145
M +61 (04) 0249 4148
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