Friday 18 March 2016

xia2 -dials spotfinding output

The latest xia2/dials nightly builds contain new output for the spotfinding step of xia2 -dials:

-------------------- Spotfinding SWEEP1 --------------------
102684 spots found on 1800 images (max 1854 / bin)
*****   **                             * * * ******  *     *
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************

1                         image                         1800

These show the number of strong spots found on images during the spot finding and may provide insight into data processing problems due e.g. to sample misalignment. This is rather a nice example, you may see rather more variation than this with more typical data, but if you see a clear minimum anywhere in the set (i.e. results tend to 0) do not be surprised if the processing fails. 

For Diamond Light Source users, this is very closely related to the per-image-analysis performed during data collection and should provide a similar level of insight. It is no accident that similar output is now visible in the summary from DIALS spot finding:

Histogram of per-image spot count for imageset 0:
102684 spots found on 1800 images (max 1854 / bin)
*****   **                             * * * ******  *     *
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
************************************************************
1                         image                         1800

No comments: