Crystallography Online: the website of the International Union of Crystallography

Hi everyone,

Perhaps it is a mistake to mention this in public (the code is neither 
complete nor perfect) but there is an attempt at parsing mar ccd headers 
into cif which can be viewed at:

http://cbflib.cvs.sourceforge.net/cbflib/CBFlib/pycbf/xmas/

The attempt was to make a cif header file which describes the geometry 
of the diffractometer at the xmas beamline at ESRF. Might be useful for 
someone else, although it is doubtful that you are putting motor 
positions into the comments sections (which do appear in vi).

For Justin's project at mar - it is great that you are doing this 
properly! The many varied and interesting configurations that ccd 
detectors can be used in mean that you might want to provide a mechanism 
to allow people to describe the axes on their instrument (eg a cif 
template file to work out which way up the ccd has been bolted on, and 
if it is a vertical or horizontal two theta arm today).

A slightly unrelated question; does anyone have dictionary entries for:

  "recommended dark current image to use for corrections"
  "recommended flat field image to use for corrections"
  "recommended grid image to use for corrections"

Seems the "raw" versus "linear" item in array_intensities tells if the 
image is corrected. In the case that we are saving raw data and applying 
corrections later, it would be handy to fill out the information above. 
For corrected data a "history" which describes the corrections applied 
would also be useful. There appear to be some interesting issues 
relating to flat field corrections on fibre optic tapers at the moment?

Best,

Jon