Ok, thank you very much. It answered  my questions.

However, I have another question about the broadening type used (Gaussian or 
Lauretzian).
We  already have all the instrument parameters defined (with the background). 
Though, how is defined  the broadening type parameter (LGmix) by default ?

When set by the user in setSampleProfile, LGmix is a float between 0 and 1 
(Gaussian and Lorentzian) but if the value is not defined this parameter is 
ignored. Thus, how is it set naturally ? Is it a constant, peak dependant, 
broadening dependant (size or mustrain) or maybe phase dependant. What define 
the default values for the broadening type in a simulation ?

Thank you very much

Best Regards

AM


________________________________
De : Toby, Brian H. <[email protected]>
Envoyé : lundi 1 mars 2021 17:40
À : [email protected] <[email protected]>; Audrey Mayrat 
<[email protected]>
Objet : Re: Clarification Request (MuStrain, Size)

Hi Audrey,

   I have not looked at the code, but GSAS-II uses microstrain and size 
parameters in only one way. They are called "HAP" because there is a set for 
each phase and for each histogram. Thus, if you are doing a simulation of one 
powder pattern for a two-phase mixture, each phase could have different size 
and mustrain values.

   Having said that, there can be a number of ways in GSASIIscriptable to set 
those values. Most likely I set up something general and clumsy initially and 
then wrote a new and improved and more specific routine later, but left the old 
one because it could be used for more purposes or so that I would not break old 
scripts. While not recommended, it is even possible to find the entries in the 
Phase.data object and change them directly.

When in doubt, you can create or modify the .gpx file in a script, save it and 
look at the values using the GUI. Or, to see what is changing in the underlying 
data structures, change a value in the GUI, save it and then look at the 
various dicts from a script.

Does this answer your question?

Brian
________________________________
From: GSAS-II <[email protected]> on behalf of Audrey Mayrat via 
GSAS-II <[email protected]>
Sent: Monday, March 1, 2021 2:58 AM
To: [email protected] <[email protected]>
Subject: [GSAS-II] Clarification Request (MuStrain, Size)

Good Morning,

I am using the python interface to do continus simulation. Those simulations 
will be used to train neural networks for the phase detection and 
quantification.

While doing it, I discovered that there was 2 ways to play with both the 
Mustrain et the Size parameters (using set H-A-P set parameter and set profile 
parameter), that to me seems equivalent, beside the profile settings (Gaussian 
or Lauretzian).

I would like to know what is the difference between both, when used for the 
simulation of XRD patterns, and which one in my cases would be the most 
suitable ?

If any one as the answer or hypothesis about it, feel free to answer.

Best Regards

A. M.
_______________________________________________
GSAS-II mailing list
[email protected]
https://mailman.aps.anl.gov/mailman/listinfo/gsas-ii

Reply via email to