Espec. Jan & Kay, I had better check this out - ville wrote the code I believe, and I have never actually checked the distribution! Cheers Eleanor
On Tue, 31 Aug 2021 at 08:01, Jan Dohnalek <dohnalek...@gmail.com> wrote: > This is good to know indeed. > Will improve my teaching now, I also did not know this is now done > automatically. Thanks for pointing it out. > > Jan > > > On Mon, Aug 30, 2021 at 9:44 PM Kay Diederichs < > kay.diederi...@uni-konstanz.de> wrote: > >> Dear Eleanor, >> >> Thanks for pointing out that CCP4 FreeRflag selects the test set in the >> highest possible symmetry for the crystal class! I didn't know that. >> >> The following sentences (which are somewhat difficult to understand for >> me) in https://www.ccp4.ac.uk/html/freerflag.html appear to document >> that: >> "The FreeR_flag is randomly and uniformly distributed >> reflexion-by-reflexion, but, additionally, if the keyword NOSYM is not set, >> all reflections that are equivalent by the symmetry of the point group of >> the twin lattice (assuming the data is twinned), obtain the same flag. This >> includes both the possibility of merohedral and pseudomerohedral twinning. >> In the latter case, the obliquity parameter can be set using the keyword >> OBL." >> >> I wonder since which CCP4 version (or date) this is the default behaviour. >> >> best wishes, >> Kay >> >> On Mon, 30 Aug 2021 18:28:23 +0100, Eleanor Dodson < >> eleanor.dod...@york.ac.uk> wrote: >> >> >Back to FreeR factors - Phenix, and I believe FreeRflag now select FreeRs >> >in the highest possible symmetry for the crystal class - eh P6/mmm for a >> >trigonal crystal, and expand the set to fill the actual space group. This >> >means the Free R assignment is suitable if later the crystal symmetry is >> >reassigned. But this was not always done in the past so if you are trying >> >to reuse free/work assignments from an old project there are >> possibilities >> >of not getting this. Maybe the best solution is to just generate a new >> Free >> >R set ? >> >Eleanor >> > >> ... >> >> ######################################################################## >> >> To unsubscribe from the CCP4BB list, click the following link: >> https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 >> >> This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a >> mailing list hosted by www.jiscmail.ac.uk, terms & conditions are >> available at https://www.jiscmail.ac.uk/policyandsecurity/ >> > > > -- > Jan Dohnalek, Ph.D > Institute of Biotechnology > Academy of Sciences of the Czech Republic > Biocev > Prumyslova 595 > 252 50 Vestec near Prague > Czech Republic > > Tel. +420 325 873 758 > > ------------------------------ > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
