  Three state-space based methods were tested in relation to the ability to
detect unidirectional coupling and synchronization of interconnected dynamical
systems. The first method, based on measure named M, was introduced by
Andrzejak et al. in 2003 [1]. The second one, based on measure L, was described
in 2009 by Chicharro et al. [5]. The third method, called convergent
cross-mapping, came from Sugihara et al., 2012 [28]. The methods were compared
on 9 test examples of uni-directionally connected chaotic systems of H\'enon,
R\"ossler and Lorenz type. The tested systems were selected from previously
published causality studies. Matlab code for the three methods is provided. The
results show that each of the three examined state-space methods managed to
reveal the presence and the direction of couplings and also to detect the onset
of full synchronization.
