[Ifeffit] Bugs in new versions of Athena and Artemis

Bruce Ravel ravel at phys.washington.edu
Thu Mar 11 08:46:13 CST 2004

On Thursday 11 March 2004 08:43 am, Schmithals wrote:
> Athena:

I'll address the comments on Artemis in a subsequent email.

> - I usually read in a rather large number of chi(k) data-files. It then
> happens often that a few of the created groups will not be displayed:
> when I mark/select such a group and press a purple/red button it might
> for example plot correctly for E, R and q; but in k-space it will simply
> give a message to the Echo Area ( .. plotting in k-space .. done! ) but
> the resulting graph will be blank. This behaviour generally occurs when
> the number of data-files is around 150 but I also observed it with less
> files. I am sure that the files to import are corrupt as they behave
> well when I read them in separately.

This has been discussed in the past on the mailing list.  As you all
know, Athena is just a front-end for Ifeffit.  Ifeffit is written in
Fortran and therefore has hardwired limitations on the amount of
memory it can access.  Athena makes a rather anemic attempt to
estimate how much memory will be needed and a similarly anemic attempt
to warn you as you approach the memory limit.  This is better than
nothing, but is flawed.

I suspect that 150 files is too many.  That is, 150 times the memory
needed to store the energy, k, and R arrays is more than Ifeffit
allows.  Once you exceed this memory limit, weird stuff will happen.

The best suggestion I can make is to split your data up into groups of
40 or 50 files and save projects files with only that number.  If you
need to merge 150 files, the best suggestion is to merge them in
groups of, say, 20 then merge the merged groups.

> - When I close the graph window the main athena program will crash. I
> remember that this behaviour has been discussed earlier.

Read the FAQ:

> - While loading (and saving) of projects with many data groups is
> reasonably fast, closing such a project requires an extremely long time. Is
>   that a normal behaviour?

It is normal behavior.  And this behavior has been bugging me more and
more lately, so it will prbably be improved in the near future.


 Bruce Ravel  ----------------------------------- ravel at phys.washington.edu
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 Naval Research Laboratory                          phone: (1) 202 767 2268
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 National Synchrotron Light Source
 Brookhaven National Laboratory, Upton, NY 11973

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