Multiple channels (multivariate) signals - Practical Biomedical Signal Analysis Using MATLAB - page 100

varies topographicaly. Hence atom g γ k can be expressed as:

n
i = 1 | R n x i

g j γ

g i γ |

2

j g i γ =

g γ k = arg max

g γ ∈

, and ∀ (3.53)

i ,

D

Another example of optimality criterion can be formulated when the multivariate
signal is obtained as an ensemble of realization of a process, e.g., multiple epochs
containing the realizations of an evoked potential. In such a case the criterion could
be analogous to the one given by (equation 3.53), but the constraint of the same phase
for all univariate atoms can be relaxed.