> I wonder if "imcalc" could be used for calculations leading to an
> "multiple file" output ( input i1... i100, output i1´ ... i100´ for
> example linear "detrended")...
I'm afraid there is no multiple file output from imcalc. To do something
like detrending, you would need code something like the untested stuff below:
___________________________________________________________________________
% get a handle for each image...
V = spm_vol(spm_get(Inf,'*.img'));
% Create output images...
VO = V;
for k=1:length(V),
[pth,nm,xt,vr] = fileparts(deblank(V(k).fname));
VO(k).fname = fullfile(pth,['detrended_' nm xt vr]);
VO(k) = spm_create_image(VO(k));
end;
dat = zeros([VO(1).dim(1:2) length(VO)]);
% Loop over planes...
for i=1:V(1).dim(3),
% Read a plane for each image...
M = spm_matrix([0 0 i]);
for k=1:length(V),
dat(:,:,k) = spm_slice_vol(V(k),M,V(1).dim(1:2),0);
end;
% do the detrending on dat, something like...
dat = reshape(dat,[prod(V(1).dim(1:2)) length(V)])';
A = [ones(length(V),1) [1:length(V)]']; % Design matrix
dat = dat - A*(A\dat); % Residuals after fitting a straight line
dat = reshape(dat',[V(1).dim(1:2) length(V)]);
% Write a plane for each image...
for k=1:length(V),
VO(k) = spm_write_plane(VO(k),dat(:,:,k),i);
end;
end;
___________________________________________________________________________
best regards,
-John
--
Dr John Ashburner.
Wellcome Department of Cognitive Neurology.
12 Queen Square, London WC1N 3BG, UK.
tel: +44 (0)20 78337491 or +44 (0)20 78373611 x4381
fax: +44 (0)20 78131420
http://www.fil.ion.ucl.ac.uk/~john
mail: [log in to unmask]
