Hi
I need to filter and resample Biosemi (.bdf) data with SPM. Running through
the tutorial, I can do all the preceding stages (e.g. montage, epoch) but
these two don't work, even on the example (subject1.bdf) data downloaded
from the SPM website.
The output in the Matlab Command Window is :
??? Undefined function or method 'butter' for input arguments of type 'double'.
Error in ==> spm_eeg_filter at 119
[B, A] = butter(filter.order, filter.PHz/(D.fsample/2), filter.band);
??? Error while evaluating uicontrol Callback
It looks like it might be a problem accessing the .m files because I get exactly
the same error message when trying the same thing on a PC without the
Signal Processing toolbox, but:
Firstly, the Signal Processing Toolbox is definitely installed and there are paths
set to the folders containing the butter and resample .m files.
(i.e. ...MATLAB\R2008b\toolbox\signal\signal)
Secondly, I get help returned for both of these (e.g. when typing 'help
butter') into the Command Window, so you'd think it must be accessing them
to some extent.
I notice that there are multiple .m files for both of these functions when I run
a search on my PC, but only those in the \signal\signal folder appear to have a
path set to them... don't know if that's relevant.
I'm using SPM8 and Matlab 2008b on a PC with Windows XP.
If anyone has any suggestions of how I can get this to work I'd be very
grateful!
Thanks in advance,
Rachel
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