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
