[Eeglablist] EEG.icaact vs. ICAcomp

[arno]

Dear George,

what version of EEGLAB are you using? In earlier versions than 5.0b, 
EEGLAB was not handling the output of Fastica properly (the weight 
matrix and the the inverse matrix were inverted). This is probably the 
problem. After you download EEGLAB, you will have to rerun ICA though. 
Please send us more comments at eeglab at sccn.ucsd.edu or to enter bugs, 
go to the Bugzilla web page

https://sccn.ucsd.edu/eeglab/bugzilla/

Best,

Arno

hughgs at duke.edu wrote:
> I'm trying to understand the interfaces to the fastica algorithm and am
> having a problem with the difference between EEG.icaact computed by
> eeg_checkset and the "icasig" output from fastica().
>
> It seems that the two should be relatively equivalent but when I check the
> difference between the two I find that,
>
> max(max(abs(EEG.icaact - ICAcomp))) = 3,
> where ICAcomp is the variable used by pop_runica() when running fastica().
>
> I'm using the eeglab_data.set that was shipped with the EEGLAB v5.03 as my
> data set.  Am I missing something?  Thanks.
>
> George S. Hugh
> 261 Hudson Annex
> (919)660-5167
> hughgs at duke.edu