The idea comes from a suggestion by Angelo Figueiredo <am dott figueiredo att fct dott unl dott pt>
and was discussed at http://thread.gmane.org/gmane.science.nmr.relax.user/1428/focus=1430.
One file per field strength is generated and named 'rex_600' for 600 MHz, for example. The new
scaling argument of the value.write user function is being used to scale the tiny field strength
independent value used internally in relax to the Rex value in rad.s^-1 that you would see in an R2
data set.
