Hi Doug,
Yes - I _think_ the answer is that the .mats are FLIRT matrices with
the coordinate centre in the corner of the image, whereas for more
useful graph plotting, the .par file has the transformations stored
relative to an image centre coordinate centre to make the different
parameters more interpretable and independent of each other.
Hope this makes sense? Cheers, Steve.
On 6 Aug 2007, at 21:43, Doug Greve wrote:
> When I run mcflirt via feat, it creates an mc directory under which
> is a prefiltered_func_data_mcf.mat directory which has a bunch of
> MAT_???? files with 4x4 matrices. I had thought that this would be
> the matrix equivalent of the rotations and translations found in
> the prefiltered_func_data_mcf.par file.
>
> The rotations do match, but I'm having a problem reconciling the
> translations. Eg,
>
> cat prefiltered_func_data_mcf.mat/MAT_0000
>
> 1.000000 0.000130 -0.000365 -0.030460
> -0.000129 1.000000 0.000970 -0.058024
> 0.000365 -0.000970 0.999999 -0.006929
> 0.000000 0.000000 0.000000 1.000000
>
> head -n 1 prefiltered_func_data_mcf.par
>
> 0.000969584 0.000364679 0.00012981 -0.0411323 -0.00362382
> -0.080172
> I would have thought that the translations in the .par (the last 3
> cols) would be the same as the last row in the MAT file, but
> (obviously) they are not. I think the values in the .par are the
> correct translations, but then what are the values in the MAT file?
> Or am I just misinterpreting something?
>
> thanks!
>
> doug
>
>
>
> --
> Douglas N. Greve, Ph.D.
> MGH-NMR Center
> [log in to unmask]
> Phone Number: 617-724-2358 Fax: 617-726-7422
>
> In order to help us help you, please follow the steps in:
> surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
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