Hi We have Farell Lytle type data. When we put that into ATHENA we get the Energy curve. But we are not able to extract that Energy converted data from ATHENA . We tried to import the data in ORIGIN but we could not do so though the graph was imported.So if there is any way to extract the data please let us know. Thanks Abhijeet
Hi Abhijeet: The Farrel Lytle data is in the form of staps with calibration points. You need to make a conversion to energy. Grant Bunker sent me this description a while ago. I have written a Python program to do the conversion but have had no time to finish it off and make it really useful. Hope this helps carlo --------------------------------------------------------------
From bunker@iit.edu Wed Aug 6 12:27:28 2008 Date: Wed, 6 Aug 2008 12:27:13 -0500 From: grant bunker
To: segre@agni.phys.iit.edu Subject: Re: Lytle database
I wrote a little conversion program in mathematica for somebody who asked a year or so ago. It should be easy to pythonize it. The main thing to remember is the first column is in motor steps (!), and the angle is a linear function of motor steps, and the rest is just Bragg's law. Things are referenced physically to the copper edge. Key parameters used in the data acquisition program are in the header: dspace is obvious, stepdeg is steps per degree in the mono, cuedge is the position of the Cu edge as measured in motor step units. So, the business end of the conversion is something like this: (*constants*) hc=12398.5; Cuenrg=8980.3; (* these things should be extracted from file header *) dspace=3.13562; cuedge=50880.; stpdeg=4000.; (* code*) const=hc/(2*dspace); thetaCu=ArcSin[const/Cuenrg]; theta[n_]:=(n-cuedge)/stpdeg*pi/180.+thetaCu e[n_]:=const/Sin[theta[n]] I'm not positive, but I think the channel offsets are already subtracted from the other columns; the offsets are just listed for documentation. ---------------------------------------------------------- On Wed, 28 Jan 2009, abhijeet gaur wrote:
Hi We have Farell Lytle type data. When we put that into ATHENA we get the Energy curve. But we are not able to extract that Energy converted data from ATHENA . We tried to import the data in ORIGIN but we could not do so though the graph was imported.So if there is any way to extract the data please let us know.
Thanks
Abhijeet
-- Carlo U. Segre -- Professor of Physics Associate Dean for Special Projects, Graduate College Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://www.iit.edu/~segre segre@debian.org
Abhijeet, Check out this link to a similar past discussion on the mailing list regarding reading data from the Farrel Lytle database, it may be helpful as well. http://cars9.uchicago.edu/pipermail/ifeffit/2005-November/002129.html Dave -----Original Message----- From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] On Behalf Of Carlo Segre Sent: Wednesday, January 28, 2009 9:13 AM To: XAFS Analysis using Ifeffit Subject: Re: [Ifeffit] EXAFS data Hi Abhijeet: The Farrel Lytle data is in the form of staps with calibration points. You need to make a conversion to energy. Grant Bunker sent me this description a while ago. I have written a Python program to do the conversion but have had no time to finish it off and make it really useful. Hope this helps carlo --------------------------------------------------------------
From bunker@iit.edu Wed Aug 6 12:27:28 2008 Date: Wed, 6 Aug 2008 12:27:13 -0500 From: grant bunker
To: segre@agni.phys.iit.edu Subject: Re: Lytle database
Hi We have Farell Lytle type data. When we put that into ATHENA we get the Energy curve. But we are not able to extract that Energy converted data from ATHENA . We tried to import the data in ORIGIN but we could not do so
the graph was imported.So if there is any way to extract the data
I wrote a little conversion program in mathematica for somebody who asked a year or so ago. It should be easy to pythonize it. The main thing to remember is the first column is in motor steps (!), and the angle is a linear function of motor steps, and the rest is just Bragg's law. Things are referenced physically to the copper edge. Key parameters used in the data acquisition program are in the header: dspace is obvious, stepdeg is steps per degree in the mono, cuedge is the position of the Cu edge as measured in motor step units. So, the business end of the conversion is something like this: (*constants*) hc=12398.5; Cuenrg=8980.3; (* these things should be extracted from file header *) dspace=3.13562; cuedge=50880.; stpdeg=4000.; (* code*) const=hc/(2*dspace); thetaCu=ArcSin[const/Cuenrg]; theta[n_]:=(n-cuedge)/stpdeg*pi/180.+thetaCu e[n_]:=const/Sin[theta[n]] I'm not positive, but I think the channel offsets are already subtracted from the other columns; the offsets are just listed for documentation. ---------------------------------------------------------- On Wed, 28 Jan 2009, abhijeet gaur wrote: though please let
us know.
Thanks
Abhijeet
-- Carlo U. Segre -- Professor of Physics Associate Dean for Special Projects, Graduate College Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre@iit.edu http://www.iit.edu/~segre segre@debian.org _______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
On Wednesday 28 January 2009 09:13:18 am Carlo Segre wrote:
The Farrel Lytle data is in the form of staps with calibration points. You need to make a conversion to energy. Grant Bunker sent me this description a while ago. I have written a Python program to do the conversion but have had no time to finish it off and make it really useful.
Much -- but not all -- of the data in the massive bitdump of measurements made by Farrel is in that form. This is a question that gets asked all the time on this list -- so much so that there is a FAQ on the topic. See question 3 at: http://cars9.uchicago.edu/iffwiki/FAQ/Data_Handling A way of converting the most common form of data in the Lytle bitdump is explained and could be easily implemented in many ways, including in a spreadsheet. The problem of weird data file formats and how Athena can deal with them is another topic that has been discussed at great length here and elsewhere. In fact, there is a whole section on the topic in the Athena User's Guide: http://cars9.uchicago.edu/~ravel/software/doc/Athena/html/import/plugin.html The information inthat link doesn't help Adhijeet import his data, but it does explain how Athena interacts with weird data files -- which is broadly useful information. B -- Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 My homepage: http://xafs.org/BruceRavel EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/
participants (4)
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abhijeet gaur
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Barton, David (DG)
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Bruce Ravel
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Carlo Segre