Hi Jack,
I suspect it simply is the x-axis labelling that is wrong - try to do a wc
on one of the tXX.txt files (the time-course text files), if there are 33
values in there everything works fine and is just labelled incorrectly.
We're out of time right now but I'll fix the labels as soon as I get a
chance
cheers
Christian
Christian F. Beckmann
Address: Oxford University Centre for Functional
Magnetic Resonance Imaging of the Brain,
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
Email: [log in to unmask] http://www.fmrib.ox.ac.uk/~beckmann/
Phone: +44(0)1865 222782 Fax: +44(0)1865 222717 Mob: +44(0)7811 189123
On Wed, 11 Dec 2002, Jack Grinband wrote:
> Hi Christian,
>
> I've analyzed several data sets and the time course of each of my components starts
> at -4 sec. Also, the FFT gives me some negative freqs i.e. x-range = [ -.07576, 1.14].
>
> My TR = 4s and I acquired 36 volumes. I dropped the first 3 volumes. That leaves 4*
> 33=132s. The range of the time course for each component is [ -4, 124], i.e. a total of
> 128s.
>
> 1. Do you have any idea why the time course starts at -4s and the FFT gives
> negative freqs?
>
> 2. Do you know what might have happened to the missing volume?
>
> thanks,
>
> jack
>
> --
>
> Jack Grinband, PhD
> Mind & Brain Institute
> Columbia University
> 518 PI Annex W. 168th St.
> NY, NY 10032
> 212-543-6931 ext 306
> [log in to unmask]
>
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