[MINC-users] nu_correct error

[Andrew Janke]

Ernest, 

What version of N3 are you running?  There have been a few "issues"
with some previous versions....  The current version is 1.10 and can
be found here:

   http://packages.bic.mni.mcgill.ca/tgz/

As for documentation on the field format, you have me there.  The only
one that could comment on this would be John Sled I guess. (the
authour).  In the meantime the best way would be to look at the code
of evaluate_field.  It takes a field file (.imp) and can turn it into
a MINC file.

Andrew


On 06/07/05, elo@neurorx.com <elo@neurorx.com> wrote:
> Hello,
> 
> I have encountered the following error while running nu_correct:
> 
> inputCompactField(): Incorrect number of coefficients
> Failure reading field file:
> XXXXXXXXXXXXX.imp
> nu_evaluate: crashed while running evaluate_field (termination status=256)
> nu_correct: crashed while running nu_evaluate (termination status=256)
> nu_correct failed on XXXXXXXXX.mnc.gz
> 
> Examination of the .imp file shows that it has 90 lines instead of the
> usual 110 lines.  Therefore it may be that nu_evaluate expects a greater
> number of field coefficients.  As a test I manually add 20 coefficients to
> the .imp file and then nu_evaluate works fine.
> 
> What could be causing this error in the automated processing?  Does
> nu_evaluate expect a different number of field coefficients than is
> provided by nu_estimate?  nu_correct has worked fine on our other scans
> so this seems to be an uncommon type of failure.
> 
> PS it would be very enlightening also to know what the parameters, matrix,
> and coefficients in the .imp file mean.  Somehow they must represent the
> non-uniformity field - but what would the mathematical formulation be?
> 
> Thanks in advance,
> 
> Ernest Lo
> NeuroRX Research
> Montreal, Canada
> 
> _______________________________________________
> MINC-users@bic.mni.mcgill.ca
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> 


-- 
Andrew Janke      (a.janke@gmail.com || www.cmr.uq.edu.au/~rotor)
Canada->Montreal                                   Cell: +1 (514) 924 2012