[MINC-users] mincmath -percentdiff

[Andrew Janke]

Hi,

I suspect that your second volume has a few voxels in it that are 0.
Thus you will get range problems.

There are a few ways around this but something like this should work

   minccalc -expression "(abs(A[1]) < 0.0001) ? 0 : (A[0]-A[1])/A[1]*100" ....


a

On Nov 21, 2007 9:57 AM, Ji Hyum KO <kojinet at bic.mni.mcgill.ca> wrote:
> Hello,
>
> mincmath -percentdiff A_BPmap1.mnc A_BPmap2.mnc A_BPdiff.mnc
>
> This command should give me the precentage difference of BPmap2.mnc
> compared to BPmap1.mnc, but it gives right values for subject A, but not
> for subject B.
>
> For subject B, all the values in the minc file is set to 3796.17 except
> several dots and those dots were set to some wierd value as well.
>
> I tried to use minccalc to do the same operation, -expression
> '(A[0]-A[1])/A[1]*100', but it gave me the same result.
>
> The input files were the binding potential map of raclopride, and they
> were generated by RPM. The images were transformed to Talairach space using
> pet_resample (mritotal and mritopet). The transformation was manually
> adjusted and added to the original xfm files.
>
> The PET images were obtained outside of MNI.
>
> Both subject A and B were scanned in the same scanner.
>
> Could you help me to fix this problem?
>
> Thanks,
>
> Ji Hyun
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
> http://www.bic.mni.mcgill.ca/mailman/listinfo/minc-users
>



-- 
Andrew Janke   (a.janke at gmail.com || http://a.janke.googlepages.com/)
Canberra->Australia    +61 (402) 700 883