Use spectrum IDs per each field strength for an error analysis for peak intensities.
Please see the spectrum.error_analysis user function documentation.
This user function will collect all spectrum IDs for each field strength separately, and call the spectrum.error_analysis with these.
This function is meant as a short-cut for the spectrum.error_analysis function.
To collect all spectrum IDs per field strength, and perform peak intensity error analysis:
[numbers=none] relax> spectrum.error_analysis_per_field()