[FieldTrip] ft_channelselection fails with negation and regex matching

[Kanal Eliezer]

Hello fieldtrip -

We have a Elekta Neuromag 306 scanner, and I'm trying to select only the gradiometers. The magnetometers are labeled 'MEGxxx1', where x can be any number, and the gradiometers are either 'MEGxxx2' or 'MEGxxx3'. However, using ft_channelselection results in the following error:

~~~~
>> ft_channelselection({'all','-STI*','-MEG*1'}, cfg.hdr.label)
??? Matrix index is out of range for deletion.

Error in ==> ft_channelselection at 287
channel([
~~~~

This error is somewhat complex, as I was able to determine that ft_channelselection recursively calls itself a number of times while running, and I was unable to figure out what is causing this problem. Any help would be appreciated. Thanks!

Eliezer Kanal


--------------------
Eliezer Kanal, Ph.D.
Postdoctoral Fellow
Center for the Neural Basis of Cognition
Carnegie Mellon University
4400 Fifth Ave, Suite 110A
Pittsburgh PA 15213
P: 412-268-4115
F: 412-268-5060