SPM99 Gem 23: Tabulating T Statistics

Subject: Fwd: Re: tabulating all statistics
From: John Ashburner <john@FIL.ION.UCL.AC.UK>
Date: Tue, 1 Jul 2003 11:47:07 +0000 (07:47 EDT)
To: SPM@JISCMAIL.AC.UK

> I was wondering if it would be possible to write t values for an
> entire volume into a file? 

Try this:

   fid=fopen('t-values.txt','w');
   P=spm_get(1,'*.img','Select statistic image');
   V=spm_vol(P);

   [x,y,z] = ndgrid(1:V.dim(1),1:V.dim(2),0);
   for i=1:V.dim(3),
     z   = z + 1;
     tmp = spm_sample_vol(V,x,y,z,0);
     msk = find(tmp~=0 & finite(tmp));
     if ~isempty(msk),
       tmp = tmp(msk);
       xyz1=[x(msk)'; y(msk)'; z(msk)'; ones(1,length(msk))];
       xyzt=V.mat(1:3,:)*xyz1;
       for j=1:length(tmp),
         fprintf(fid,'%.4g %.4g %.4g\t%g\n',...
                 xyzt(1,j),xyzt(2,j),xyzt(3,j),tmp(j));
       end;
     end;
   end;
   fclose(fid);

best regards,
-John
                

As noted in a 2 Feb 2004 email, to eliminate all voxels below a certain threshold, change

     msk = find(tmp~=0 & finite(tmp));

to

     msk = find(tmp>0 & finite(tmp));


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