Hi Edward, I have a general question regarding how to pick signals prior to relaxation rate fitting.
Following the rationale of [1] fitting the data with a two-parameter exponential decay is preferable. With relax, I can choose to do so. The question remains if "picking noise" – i.e. picking signal intensities at the position of the reference peaks, although the signal has decayed already – is a good idea. To me it seems only logical that "picking noise" should not be done. The signal decays to zero whatsoever (given the pulse sequence is properly set up) and by picking signals where no signal should be I may pick artifacts that are not distributed evenly over the base plane of the spectrum. Which means, I may be introduce artificial offsets. However relax seems not be happy when I try to use peak lists for T1/T2 relaxation fitting if the lists have different lengths. I always have to do "noise picking", otherwise already the grid_search fails when encountering a incomplete time series. Is the behaviour intended, do I need a complete time series of each amino acid? Or am I missing something? Or am I completely misguided with my not-picking-noise approach? Cheers Martin [1] Viles, J. H., Duggan, B. M., Zaborowski, E., Schwarzinger, S., Huntley, J. J., Kroon, G. J., Dyson, H. J., et al. (2001). Potential bias in NMR relaxation data introduced by peak intensity analysis and curve fitting methods. Journal of biomolecular NMR, 21(1), 1–9. -- Martin Ballaschk AG Schmieder Leibniz-Institut für Molekulare Pharmakologie Robert-Rössle-Str. 10 13125 Berlin [email protected] Tel.: +49-30-94793-234/315 Büro: A 1.26 Labor: C 1.10 _______________________________________________ relax (http://www.nmr-relax.com) This is the relax-users 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-users
