  For a system of coupled anharmonic oscillators we compare the convergence
rate of the variational collocation approach presented recently by Amore and
Fernandez (2010 Phys.Scr.81 045011) with the one obtained using the optimized
Rayleigh-Ritz (RR) method. The monotonic convergence of the RR method allows us
to obtain more accurate results at a lower computational cost.
