Dear phenixbb subscribers, I sent the message below to the CCP4BB and phenixbb at the same time last Friday. It went straight through to the CCP4BB subscribers but was caught by the phenixbb Mailman because its size exceeded 40K. Nigel, as moderator of this list, did his best to rescue it, but all his attempts failed. He therefore asked me to resubmit it, now that he has increased the upper size limit. Apologies to those of you who are also CCP4BB subscribers, who will already have received this message and the follow-up discussion it has given rise to. With best wishes, Gerard. ----- Forwarded message from Gerard Bricogne <gb10> ----- Date: Fri, 1 Jun 2018 17:30:48 +0100 From: Gerard Bricogne <gb10> Subject: Table 1 successor in 3D? To: [email protected], [email protected] Dear all, Bernhard Rupp has just published a "Perspective" article in Structure, accessible in electronic form at https://www.cell.com/structure/fulltext/S0969-2126(18)30138-2 in which part of his general argument revolves around an example (given as Figure 1) that he produced by means of the STARANISO server at http://staraniso.globalphasing.org/ . The complete results of his submission to the server have been saved and may be accessed at http://staraniso.globalphasing.org/Gallery/Perspective01.html and it is to these results that I would like to add some annotations and comments. To help with this, I invite the reader to connect to this URL, type "+" a couple of times to make the dots bigger, and press/toggle "h" whenever detailed information on the display, or selection of some elements, or the thresholds used for colour coding the displays, needs to be consulted. The main comment is that the WebGL interactive 3D display does give information that makes visible characteristics that could hardly be inferred from the very condensed information given in Table 1, and the annotations will be in the form of a walk through the main elements of this display. For instance the left-most graphical object (a static view of which is attached as "Redundancy.png") shows the 3D distribution of the redundancy (or multiplicity) of measurements. The view chosen for the attached picture shows a strong non-uniformity in this redundancy, with the region dominated by cyan/magenta/white having about twice the redundancy (in the 6/7/8 range) of that which prevails in the region dominated by green/yellow (in the 3/5 range). Clear concentric gashes in both regions, with decreased redundancy, show the effects of the inter-module gaps on the Pilatus 2M detector of the MASSIF-1 beamline. The blue spherical cap along the a* axis corresponds to HKLs for which no measurement is available: it is clearly created by the detector being too far from the crystal. The second (central) graphical object, of which a view is given in Figure 1 of Bernhard's article and another in the attached picture "Local_I_over_sigI.png") shows vividly the blue cap of measurements that were missed but would probably have been significant (had they been measured) cutting into the green region, where the local average of I/sig(I) ranges between 16 and 29! If the detector had been placed closer, significant data extending to perhaps 3.0A resolution would arguably have been measured from this sample. The right-most graphical object (of which a static view is attached as "Debye-Waller.png") depicts the distribution of the anisotropic Debye-Waller factor (an anisotropic generalisation of the Wilson B) of the dataset, giving yet another visual hint that good data were truncated by the edges of a detector placed too far. Apologies for such a long "STARANISO 101" tutorial but Bernhard's invitation to lift our eyes from the terse numbers in Table 1 towards 3D illustrations of data quality criteria was irresistible ;-) . His viewpoint also agrees with one of the main purposes of our STARANISO developments (beyond the analysis and remediation of anisotropy, about which one can - and probably will - argue endlessly) namely contribute to facilitating a more direct and vivid perception by users of the quality of their data (or lack of it) and to nurturing evidence-based motivation to make whatever extra effort it takes to improve that quality. In this case, the undeniable evidence of non-uniformity of redundancy and of a detector placed too far would give immediate practical guidance towards doing a better experiment, while statistics in Table 1 for the same dataset would probably not ... . Thank you Bernhard! With best wishes, Gerard, for and on behalf of the STARANISO developers ----- End forwarded message -----
