[Ifeffit] How to use Larch as backend for Athena and Artemis on Windows

[Bruce Ravel]

Hi Hiroyuki,

Sorry I didn't respond yesterday.  Yesterday was a bit of crazy day...

I suppose that this is still a work in progress.  I believe that Demeter 
works with Larch on Windows, but it is certainly not as easy or 
convenient yet as it should be.

In the place where Demeter got installed on your computer, there is a 
folder called \perl\site\bin -- you can look at the properties of the 
Athena desktop icon to see where that is.  In that folder is the 
"dathena.bat" file which the Athena desktop icon points at.

You should also find a file called "lathena.bat".  Try running that or 
pointing your desktop icon at it instead.

The difference between "lathena.bat" and "dathena.bat" is line 25 that 
sets an environment variable that Demeter uses to decide which of 
ifeffit or larch to use.

Obviously, there are number of other ways to get this environment 
variable set.  The bottom line is, yes, there is a switch.  The switch 
is the DEMETER_BACKEND environment variable.

Unfortunately, that switch cannot be in the configuration files, 
although what you tired in item 2 of your email was a sensible guess. 
It turns out that the choice of larch/ifeffit has to made long before 
the configuration files are read.

Do let me know how you get on.  While Demeter + larch should work, there 
are still almost certainly problems.  I need to get a new version of the 
Demeter installer out soon, so it would be nice to get some feedback in 
this area.

As for using Demeter + larch + 100s of file -- it should work after a 
fashion.  But I worry that Athena's performance might not be what you 
are hoping for.  Athena does a lot of things that are more user-friendly 
than performance-friendly....


Cheers,
B


On 08/15/2017 06:10 AM, ASAKURA, Hiroyuki wrote:
> Dear all,
> 
> I would like to use the latest Larch as backend for Athena and Artemis 
> on Windows to handle hundreds of XAS data (, hopefully).
> But, I'm stuck. I would appreciate any comments and suggestions.
> 
> Matt announced it is now possible on this list, but I still cannot do it 
> on Windows.
> 
> [Ifeffit] Larch 0.9.33
> http://millenia.cars.aps.anl.gov/pipermail/ifeffit/2017-April/009091.html
> 
>> The "server mode" for Athena and Artemis now works on all platforms and I
>> strongly encourage everyone to use this over the ifeffit back end.
> 
> Here is what I did.
> 
> Environment:
> Windows 10 Pro (Japanese)
> Demeter 0.9.25 (via official website)
> Python 3.6 (official distribution)
> 
> 1. Installation of the latest Larch
> 
>> git clone https://github.com/xraypy/xraylarch.git (sha1: 
>> 5a372cfe1368a8ac10c2ebfc5bef4e9a9a325f6d)
>> cd xraylarch
>> python setup.py install
> # Some dependency related to XRD is not fulfilled.
> 
> 2. Start Larch server
> 
>> cd %LOCALAPPDATA%\Programs\Python\Python36\Scripts
>> python larch_server start
> larch_server port=4966: started
> 
> I found a parameter of peakfit backend in demeter.ini and changed to 
> larch, but did not work (as expected).
> 
> In the dathena.log, Athena still uses ifeffit as backend.
> 
>> perl version: v5.18.2
>> backend: ifeffit
> 
> Should I compile Demeter package by myself to use the Larch backend?
> Or, is there any "switch" to use Larch?
> 
> Thanks in advance,
> 
> ASAKURA, Hiroyuki
> 
> 


-- 
  Bruce Ravel  ------------------------------------ bravel at bnl.gov

  National Institute of Standards and Technology
  Synchrotron Science Group at NSLS-II
  Building 743, Room 114
  Upton NY, 11973

  Homepage:    http://bruceravel.github.io/home/
  Software:    https://github.com/bruceravel
  Demeter:     http://bruceravel.github.io/demeter/