Paul, both your emails are partly correct. Rotation+translation, called skew transformation (words 25-37) is supported by CCP4 maplib and PyMOL. It's mentioned in the MRC/CCP4 2000 specification on CCP-EM page: https://www.ccpem.ac.uk/mrc_format/mrc2000.php although it's not mentioned in the 2014 version of this spec. I don't know if any program apart from PyMOL is using it.
When Tom wrote about the shift of origin, he must have meant N[XYZ]START fields. Marcin On Fri, Jan 28, 2022 at 6:00 AM Paul Emsley <pems...@mrc-lmb.cam.ac.uk> wrote: > > On 27/01/2022 01:13, Paul Emsley wrote: > > > > Alas, I have not done what I think you want (which is to say, to use > > the extented CCP4/MRC map header information to represent an arbitrary > > rotation/translation). > > > > After having read Tom's reply about these > rotation/translation/interpolation issues on the ChimeraX mailing list > I'd like to correct a misunderstanding I had about what Coot wasn't > doing. There is an unused (by Coot) slot in the CCP4/MRC map header, I > had thought that the slot allows rotation and translation but it does > not - it allows a shift of origin (translation) only. Everything Tom > said was on the money. > > Paul. > > ######################################################################## > > To unsubscribe from the COOT list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=COOT&A=1 > > This message was issued to members of www.jiscmail.ac.uk/COOT, a mailing list > hosted by www.jiscmail.ac.uk, terms & conditions are available at > https://www.jiscmail.ac.uk/policyandsecurity/ ######################################################################## To unsubscribe from the COOT list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=COOT&A=1 This message was issued to members of www.jiscmail.ac.uk/COOT, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
