Hi - you can find the original design matrix in text form in the
<something>.feat/design.mat file. If you want the form of the gammas that
were used to convolve the original timing waveform then you can generate
these by setting up an original waveform that has a single spike in it,
setting very low TR for the (nonexistant) dataset and then saving the
output to a temporary set of design files. Or you could look at the
equations in $FSLDIR/src/feat5/feat_model.c to find out the exact
implementation. You are right that the fitted weights are in the pe
images.
Cheers.
On Fri, 9 Jan 2004, SUBSCRIBE FSL Zhang, X wrote:
> Hi FSL college:
> I did one exp and got FSL results (three gamma bases).
> To get the partial model or the design matrix of another temporal
> modulation, I need:
> 1. the wave forms of the three gamma bases.
> 2. the weight of each gamma (is it pe?)
> 3. the formula convolving the three gamma*weight with my basic shape
> (is it ifft(fft(sum(gamma*weight)).*fft(basic shape)) in matlab ?)
> Appreciate your help.
> Xian
>
Stephen M. Smith DPhil
Associate Director, FMRIB and Analysis Research Coordinator
Oxford University Centre for Functional MRI of the Brain
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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