fd.dof matrix

[Sameer Walawalkar]

Dear Fieldtrippers,

I have a question about calculating degrees of freedom. I get (after
freqdescriptives)
fd.dof  = [46665x26 double];

However, dof = 2 x (Number of trials) x (number of tapers) and my trials
are of equal length and I use padding. So I think (and my understanding
could be wrong) this huge matrix is a waste of space as the dofs are going
to be the same for every pair on each trial. How can I then ensure that
freq.dof is just a number and can be still used later on?

I am using the following configuration settings.
cfgCSD = [];
cfgCSD.ouput = 'powandcsd';
cfgCSD.method = 'mtmfft';
cfgCSD.keeptrials = 'yes' ;
cfgCSD.keeptapers = 'no' ;
cfgCSD.calcdof    = 'yes';
cfgCSD.tapsmofrq = 4;
cfgCSD.foilim = [f1 f2];
CSD = freqanalysis(cfgCSD, data);

cfg = [];
cfg.cohmethod = 'plv';
fd = freqdescriptives(cfg, CSD)


Thanks,
sameer

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