Re: [bug #22008] Interpolation with relax.plot_disp_curves, creates un-even number of CPMG blocks.Re: [bug #22008] Interpolation with relax.plot_disp_curves, creates un-even number of CPMG blocks.Sound good with a flag, default to True. That means less code interruption. :-) Best Troels 2014-05-04 12:12 GMT+02:00 Edward d'Auvergne <edward@xxxxxxxxxxxxx>:
I might try implementing this user function change, and store the cdp.ncyc_even flag. Then you could use it for the interpolation. Regards, Edward On 4 May 2014 11:59, Edward d'Auvergne <edward@xxxxxxxxxxxxx> wrote: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 <edward@xxxxxxxxxxxxx> 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 <edward@xxxxxxxxxxxxx> 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 <tlinnet@xxxxxxxxxxxxx> 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 <NO-REPLY.INVALID-ADDRESS@xxxxxxx>: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/