View source for Matlab Code for Reducing FA

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function alteredFAmasked = AlterFA(dt6, mask, densitymap, effectsize)

% input:
%   dt6: ie dt.dt6 (can use dt=dtiLoadDt6('dt6.mat'))
%   mask: name of brain mask, ie 'ab_mask.nii.gz'
%   densitymap: image of fiber density (betw 0 and 1), i.e. using
%       dtiComputeFiberDensityNOGUI
%   effectsize: the factor by which to lower/raise FA (to be weighted by
%       fiber density). With effectsize of 0.1, weighted effectsize =
%       0.1*fiberdensity, and newFA = origFA*[1-(weighted effectsize)]
%
% returns:
%   XxYxZ image with altered fa, in image space
%
% 2009.11.15 JT

fa = dtiComputeFA(dt6);
brainMask=readFileNifti(mask);
brainMask.data=double(brainMask.data);
% effectsize = .1;

weightedESmap = effectsize*densitymap;
alteredFA = fa.*(1-weightedESmap);
alteredFAmasked = alteredFA.*brainMask.data;

% fa = dtiComputeFA(dt6);
% weightedESmap = effectsize*densitymap;
% alteredFA = fa.*(1-weightedESmap);

return