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Bug 2146 - ica cleanup problems with numcomponent < numchannel
| Status | ASSIGNED |
| Reported | 2013-04-27 12:26:00 +0200 |
| Modified | 2013-05-09 08:03:22 +0200 |
| Product: | FieldTrip |
| Component: | core |
| Version: | unspecified |
| Hardware: | PC |
| Operating System: | Mac OS |
| Importance: | P3 normal |
| Assigned to: | Johanna |
| URL: | |
| Tags: | |
| Depends on: | |
| Blocks: | |
| See also: |
Robert Oostenveld - 2013-04-27 12:26:30 +0200
on behalf of Ana: I've always run an ICA to remove eye blinks and heartbeat, but instead of saving the data file, I would save the unmixing matrix and then do the component rejection later, as a part of some other script. So far, I've always done this using the same number of components as there are MEG channels. This time I opted for using a smaller number of components, but I realized that it does not work unless I transpose the unmixing (i.e. comp.topo) matrix. To clarify, this is what I do: cfg = []; cfg.unmixing = comp.topo'; cfg.topolabel = comp.topolabel; comp_data = ft_componentanalysis(cfg, data); If I don't transpose comp.topo, then I get an error saying that the number of channels is not accurate. Is this the way it's supposed to be? It is not clear from the text of 'help ft_componentanalysis', although there it is mentioned that the unmixing matrix is of dimensions NxN (and not NxM, which is my case). I'm now starting to wonder whether I should have always transposed this matrix.