[Ifeffit] 30 element detector data in athena

Bruce Ravel ravel at phys.washington.edu
Mon Oct 6 16:35:25 CDT 2003

On Monday 06 October 2003 05:00 pm, Vivek S. Murthi wrote:
> Hi Matt, Bruce..
> Athena could not open files from NSLS beamline X10C vax machine which has 
> data in the form of .XFS. So, I converted it to *.dat and made it look like 
> a dat file from NSLS beamline X 11a. Athena doesnot give me any prompt for 
> incompatability but it simply crashes and closes. The data I have is from a 
> 13 element detector, so there are about 38 columns of data. I am not sure 
> if this would make Athena crash. If So, do you have any suggestions to 
> overcome this.

Vivek (and everyone else),

It is very difficult for me to comment on a problem like this without
being shown the data file that causes the problem.  Without giving me
sufficient infomation to reproduce the problem on my own computer, it
is unreasonable to expect that I should be able to help you.

I give some guidelines to reporting problems with my software at this
If anyone on this mailing list has never looked at that web page,
now would be a fine time to do so.

For the current problem, Vivek, I suggest that send me a copy of the
data file that is causing the problem.  Then I will be able to examine
the problem.  If possible, I will suggest a work-around.  If not, I
should be able to deliver a solution with the next release.

>From the description you gave, I have a few suspitions:

1. As I recall, there is a column of data in the X10C output file that
   is not given enough space for a negative sign.  If that number is
   negative, two columns run together,  Ifeffit will have trouble with
   a column containing a "number" like "0.123-1.000".

2. There are some quirky aspects to how Athena and Ifeffit negotiate
   the information about how many columns are in a data file.  It
   works fine when there are a handful or two of columns, but I have
   seen trouble with data containing several dozen columns.  If the
   column labels are more than a couple characters long, Athena may
   simply refuse to acknowledge many of the columns.  That doesn't
   seem like something that would cause a crash, but who knows...

I suspect that, for now, you may need to consider doing some
preprocessing of the 38-column data file before sending it off to
Athena.  Presumably, some of those columns are used for dead-time
correction.  Since Athena does not currently do deadtime correction,
you will need to do some pre-processing in any case should your data
require deadtime correction.  You may consider taking a look at
SixPack.  Sam has written a nice dead-time correction tool.

 Bruce Ravel  ----------------------------------- ravel at phys.washington.edu
 Code 6134, Building 3, Room 222
 Naval Research Laboratory                          phone: (1) 202 767 5947
 Washington DC 20375, USA                             fax: (1) 202 767 1697

 NRL Synchrotron Radiation Consortium (NRL-SRC)
 Beamlines X11a, X11b, X23b
 National Synchrotron Light Source
 Brookhaven National Laboratory, Upton, NY 11973

 My homepage:    http://feff.phys.washington.edu/~ravel 
 EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/

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