It would be useful if support for nlinLS/NMRPipe peak lists could be added to relax. The nlinLS package is used for lineshape analysis of peaks. see:

1. http://spin.niddk.nih.gov/NMRPipe/ref/prog/index.html, and
2. the 'relax.tar.Z' example provided on the NMRPipe download page

Input to nlinLS = a series of HSQC data (e.g. T1 or T2 series data), and a base spectrum peak list (with optional assignments).

Output = a single peak list with normalized peak intensities from the data series.

The nlinLS formatted peak list is different from what relax uses for NMRView/Sparky/Xeasy. For example, in the sample scripts relax_fit.py, 10 individual files (peak lists) are read in and associated with specific relaxation times. In the case of a nlinLS peak list, a single peak list with normalized intensities would be read in, and the relaxation times would need to be specified for each normalized intensity column, as compared to individual files for NMRView/Sparky/Xeasy. A range of column indexes will need to be specified to extract the normalized peak intensities.