“…The LL method is accurate, stable and conserves the dynamical properties of the original continuous time system. It was first introduced by [Ozaki, 1989[Ozaki, , 1992a, later elaborated by [Biscay et al, 1996] and extensively developed in recent years [Carbonell et al, 2002De la Cruz et al, 2007;De la Cruz et al, 2006;Jimenez et al, 1998Jimenez et al, , 1999Jimenez et al, , 2005Jimenez, 2002;. Though originally restricted in its applications to neuroimaging [Valdes et al, 1999a,b;Riera et al, 2004Riera et al, , 2006Riera et al, , 2007, the LL method has gained popularity in recent years.…”