Hi Paul, Mathilde and Dominique,
I have noticed that your input data appears to be in the multi-column NMRPipe seriesTab format. Is this correct? If so, note that this is currently not supported but that Troels Linnet is in the process of implementing this support. It is close, but not quite there yet. If you need to input your data into relax in the meantime, I would suggest using what is called the generic file format. You can copy the data file, and then add a column with the residue name and number (and spin name if you are looking at multiple spins per residue). Then you just specify the spin system and data columns in the spectrum.read_intensities user function (in the script or GUI).
Regards,
Edward
NMRPipe seriesTab support.