[Eeglablist] Topographic plot question

[Thanasis Koutras]

I'm interested in plotting the topographic map of a set of specific 
independent components that ICA has found on some EEG recordings. The 
number of EEG electrodes is 64. However the problem I face, is that the 
only data that I have, is a subset of N independent components where 
N<number of electrodes together with the N vectors of the ICA weights (W 
has dimension of Nx64) and the channel locations.
Would it be possible to perform such a thing? I know that classical ICA 
results in a separating SQUARE matrix 64x64, the inverse of which is 
used by topoplot (the columns of A=inv(W) to be more specific).
In my case however the separating matrix W is rectangular and no matrix 
inversion can be performed. Can the pseudo-inverse of W be used without 
error? Would this work for the case of say only one independent component?
Has anyone faced the same problem?

Thanks in advance,
Thanasis

-- 
Athanasios Koutras, PhD
Electrical & Computer Engineer
University of Patras
26100 Patras, Hellas
Tel: (+30)2610 969116
e-mail: koutras at giapi.wcl2.ee.upatras.gr