https://wiki.uni-konstanz.de/xds/index.php?title=Inverse_beam&feed=atom&action=history Inverse beam - Revision history 2024-03-28T21:28:58Z Revision history for this page on the wiki MediaWiki 1.39.6 https://wiki.uni-konstanz.de/xds/index.php?title=Inverse_beam&diff=2567&oldid=prev Kay: Created page with "'''Question''': We are trying to automate XDS processing for data being collected at the beamline. We see a lot of people collecting data using inverse beam anywhere in the range..." 2011-11-12T09:53:14Z <p>Created page with &quot;&#039;&#039;&#039;Question&#039;&#039;&#039;: We are trying to automate XDS processing for data being collected at the beamline. We see a lot of people collecting data using inverse beam anywhere in the range...&quot;</p> <p><b>New page</b></p><div>&#039;&#039;&#039;Question&#039;&#039;&#039;: We are trying to automate XDS processing for data being collected at the<br /> beamline. We see a lot of people collecting data using inverse beam<br /> anywhere in the range of 90 to 120 degrees for the first wedge with the<br /> starting angle say zero. A corresponding inverse wedge with the above<br /> mentioned range gets collected starting at frame 181 (they use 1° frames). So now they have two<br /> wedges of data for the same crystal but with missing frame numbers and<br /> corresponding missing wedges of data. How does XDS handle such situations? <br /> <br /> &#039;&#039;&#039;Answer&#039;&#039;&#039;: as long as XDS can correctly calculate the phi value from the frame number, processing works &quot;out of the box&quot;, which means with a single XDS run you can process both wedges. XDS will print out an error message for each missing frame, but these messages can simply be ignored - there is no harm associated with them.<br /> <br /> But this _requires_ that there is e.g. no &quot;off-by-one&quot; problem (second wedge should start at frame 181, &#039;&#039;not&#039;&#039; at frame 180), or other offset! If you collect 0.5° frames, of course the second wedge should start at framenumber 361.<br /> <br /> In case the frames of the second half have frame numbers which do not fit, then an easy way is to create a directory with symlinks to the frames of both wedges, and to give the symlinks the appropriate frame numbers. Of course this needs a script!<br /> <br /> In general, however, there is no real advantage (that I can think of) to a _single_ XDS run; you might as well have two runs and merge the resulting files together, using XSCALE. Use REFERENCE_DATA_SET=&lt;firstwedge_xdsdirectory&gt;/XDS_ASCII.HKL for the second wedge; that ensures consistent indexing.</div> Kay