The defaults for a relax_disp.cpmg_setup could be: relax_disp.cpmg_setup(spectrum_id=None, cpmg_frq=None, ncyc_even=True)
This can then be expanded in the future for special CPMG dispersion experiment types (CW decoupling vs. pi pulses, etc.) where the numeric model would require changes. Regards, Edward On 4 May 2014 11:53, Edward d'Auvergne <[email protected]> wrote: > Sorry, that was a bad typo, it should be Flemming Hansen's dispersion > pulse sequence! > > On 4 May 2014 11:52, Edward d'Auvergne <[email protected]> wrote: >> Hi, >> >> It depends on the pulse sequence. Here is one I found written by >> Flemming Hanser where you can use odd numbers: >> >> http://nmrwiki.org/psdb/kaylab/vnmrsys/psglib/CaHD_cpmg_GLY_dfh_600_v1.c >> >> Look for the comment: >> >> "ncyc can be either even or odd :)" >> >> Such sequences are probably in the minority though. Anyway, maybe we >> need a new user function. It would be good to have a series of user >> functions for specifying the experimental information. We already >> have that with: >> >> spectrometer.frequency >> relax_disp.exp_type >> relax_disp.relax_time >> relax_disp.cpmg_frq >> >> So keeping along these lines, maybe we need to have a >> relax_disp.cpmg_even_ncyc user function? Or we rename >> relax_disp.cpmg_frq to relax_disp.cpmg_setup and have that user >> function reserved for all CPMG pulse sequence info? What do you >> think? Renaming user functions does require a relax minor version >> number change though, so introducing it before relax 3.2.0 is a good >> idea. >> >> Regards, >> >> Edward >> >> >> >> >> >> >> On 4 May 2014 11:24, Troels Emtekær Linnet <[email protected]> wrote: >>> Hi Edward. >>> >>> The number of CPMG blocks has to be an even number. >>> >>> I remember this clearly, since I once did an CPMG experiment, with >>> some ncycs equal 4, 10, 15, 20, 25, ... >>> >>> And the intensities for all eksperiments with odd NCYC number was horrible. >>> >>> Kaare told me, that ncycs always has to be even. >>> That was something that Mikael Akke also have insisted on. >>> >>> But that day, I could not easily find it in the literature, so I left >>> it and accepted just another fact of NMR. >>> >>> And when I did the interpolated graphs with an odd-number of NCYC, >>> that looked weirdo. >>> Sig-saw all over the place. >>> >>> I actually think it could be a input check in relax, warning the user >>> if the number of CPMG blocks are not equal? >>> >>> And, I would be very happy to find it in the literature. :-) >>> Have you ever come around this? >>> >>> Best >>> Troels >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> 2014-05-04 11:06 GMT+02:00 Edward d Auvergne >>> <[email protected]>: >>>> Follow-up Comment #2, bug #22008 (project relax): >>>> >>>> If this is a restriction of only the B14 analytic CPMG model >>>> (http://wiki.nmr-relax.com/B14), it would be best if only the B14 is >>>> affected. >>>> There is no need to restrict the numeric models based on the artificial >>>> limitation of an unrelated model. Maybe the best solution would be to >>>> check >>>> if the model is B14, and if so skip odd interpolation points? >>>> >>>> _______________________________________________________ >>>> >>>> Reply to this item at: >>>> >>>> <http://gna.org/bugs/?22008> >>>> >>>> _______________________________________________ >>>> Message sent via/by Gna! >>>> http://gna.org/ >>>> _______________________________________________ relax (http://www.nmr-relax.com) This is the relax-devel mailing list [email protected] To unsubscribe from this list, get a password reminder, or change your subscription options, visit the list information page at https://mail.gna.org/listinfo/relax-devel
