[MINC-users] minctracc - different results on 32 vs 64 bit

[D. Louis Collins]

An interesting confirmation: I've just run automated HC segmentation  
with MAC  (64b) and Linux (32b) implementations of the pipeline using  
non-linear registration of minctracc.

I find that on average over 20 subjects, on both left and right HC,  
there is a 2% average magnitude difference in label volume between the  
32bit and 64bit pipelines.  (and there is a 0.5% bias in the  
magnitude).  However, the correlation between the 32bit and 64bit HC  
volumes is 0.990 - so the results are similar, but not the same.

A potential 'gotcha' to worry about.

-Louis

On Dec 9, 2008, at 2:44 PM, Vladimir Fonov wrote:

> Hello,
>
> we came a cross an interesting behavior of minctracc - it produces
> slightly different results depending on the architecture.
>
> I run mritotal on 9 subjects and the differences between 32 and 64 bit
> version runs are up to  0.3 degree in determining rotations, 0.1 mm in
> terms of shifts and up to 0.01 in scale.
>
> -- 
> Best regards,
>  Vladimir S. Fonov ~ vladimir dot fonov at gmail dot com
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