d = spm('dir');
addpath(fullfile(d,'toolbox','DARTEL'),'-BEGIN');
P = {fullfile(d,'tpm','grey.nii'); fullfile(d,'tpm','white.nii')};
P1 = fullfile(d,'canonical','avg152T1.nii');
N = nifti(P);
pl = 42;
f = N(1).dat(:,:,pl)+N(2).dat(:,:,pl);
f = (f+flipud(f))/2;
f = min(f*2,1);
d = size(f);
[i,j] = ndgrid((1:d(1))-(d(1)+1)/2,(1:d(2))-(d(2)+1)/2);
g = (i.^2*0.7+(j-20).^2<25^2 | i.^2*0.7+(j+20).^2<25^2) &...
(i.^2*0.7+(j-20).^2>10^2 & i.^2*0.7+(j+20).^2>10^2);
g = spm_conv(g*1,2);
figure('color','black')
cmap = linspace(0,2,64)';
cmap = min([cmap*0.3,cmap*0.5,cmap*0.75],1);
colormap(cmap);
NF = nifti(P1);
ff = NF.dat(:,:,pl);
ff = (ff+flipud(ff))/2;
v = zeros([d,2]);
for i=1:20
v = dartel2(v,g,f,[2 10 1 0.0001 0.01 3 3 5 1]);
y = dartel2('Exp', v);
g1 = spm_sample_vol(ff,y(:,:,1),y(:,:,2),ones(d),1);
g1 = g1+flipud(g1);
imagesc(g1');
axis image xy off
drawnow
end