  An in-field interaction plot, delta-M_R, has been recently introduced,
presenting important advantages over the classical remanence plots. Here a
general delta-M_R is proposed, allowing to assess interactions even in systems
with shifted and asymmetric major loops. To construct such a plot, a recoil
loop and the position of the center of the major loop are only needed. Applying
the method on exchange-biased Co/IrMn bilayer gives two types of delta-M_R
obtained for measuring field either parallel or antiparallel to the
exchange-bias direction. This provides valuable information on the reversal
mechanism and allows distinguishing between effects coming from magnetic
coupling into the ferromagnet (Co) and those stemming from interactions in its
interface with the antiferromagnet (IrMn). The essentially nonzero general
delta-M_R plot obtained from the major loop revealed to be a precise measure of
the reversal asymmetry. The technique can readily be adjusted for use in other
scientific fields where hysteresis is observed. We provide free software which
generates such delta-M_R plot(s).
