Back to the main page.
Bug 658 - Neuromag-306 data incompatible with ft_rejectvisual
| Status | CLOSED FIXED |
| Reported | 2011-05-11 20:44:00 +0200 |
| Modified | 2011-05-23 10:36:07 +0200 |
| Product: | FieldTrip |
| Component: | preproc |
| Version: | unspecified |
| Hardware: | PC |
| Operating System: | Mac OS |
| Importance: | P1 normal |
| Assigned to: | Eelke Spaak |
| URL: | |
| Tags: | |
| Depends on: | |
| Blocks: | |
| See also: |
Eliezer Kanal - 2011-05-11 20:44:36 +0200
Created attachment 48 bad scale in channel view Neuromag-306 data contains both magnetometers and gradiometers, each of which should be viewed on a unique scale. Personal experience has shown that to show both side-by-side the gradiometers should be scaled down by a factor of 10-20. As rejectvisual simply plots all channels next to each other, the gradiometer traces are completely out of proportion to the scale of the plot, making them unusable. (See attached images.) The way I've solved this is by including enabling two extra cfg parameters in ft_rejectvisual, "magscale" and "gradscale". I implemented them as follows: if ~isempty(cfg.magscale) scaled = 1; chansel = match_str(tmpdata.label, ft_channelselection('MEG*1', tmpdata.label)); for i=1:length(tmpdata.trial) tmpdata.trial{i}(chansel,:) = tmpdata.trial{i}(chansel,:) .* cfg.magscale; end end if ~isempty(cfg.gradscale) scaled = 1; chansel = match_str(tmpdata.label, ft_channelselection({'MEG*2','MEG*3'}, tmpdata.label)); for i=1:length(tmpdata.trial) tmpdata.trial{i}(chansel,:) = tmpdata.trial{i}(chansel,:) .* cfg.gradscale; end end This simply copies the other channel scaling techniques that start at line 230. I don't know whether this code would interfere with other types of systems, but I figured I'd submit it so you can examine/test it out.
Eliezer Kanal - 2011-05-11 20:45:10 +0200
Created attachment 49 bad channels in Trial view
Eliezer Kanal - 2011-05-13 20:10:11 +0200
Created attachment 52 bad data in time-frequency plot I just noticed today that this issue also affects ft_multiplotTFR, when using the `neuromag306all.lay` file. See attachment.