  We present results of comprehensive seismic modelling of the B-type
main-sequence pulsator $\nu$ Eridani, which consists in parallel fitting of the
pulsational frequencies and corresponding values of the complex, nonadiabatic
parameter $f$, defined by the bolometric flux perturbation. This kind of
studies, which we call {\it complex asteroseismology}, provides a unique test
of stellar opacities. Our results indicate a preference for the OPAL data.
