fd.dof matrix

[Robert Oostenveld]

On 16 Jul 2007, at 17:36, Sameer Walawalkar wrote:
> 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?

The dof can be different if you have variable trial lengths'. That
happens if you use partial artifact recection, or can also be the
result of your trial function. That in combination with multitapers
results in different dofs.

There are only a few very specific instances where the dof is
required, so usually you can throw it away without any consequences.

Robert

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