[MINC-users] nu_evaluate crash

[Jonathan HARLAP]

Hi Simon,

The direction cosines attribute should always be present, regular or 
irregular, as it describes the directions of the axes that define the 
image dimensions.  The irregularity has to do with a dimension with 
nonuniform step sizes.  Assuming that the step sizes are basically all 
the same (within the irregular dimension, I mean) and that the 
irregularity is insignificant, you can fix it with:

mincresample -nearest_neighbour irregular.mnc regular.mnc

There are also other ways which have been previously discussed on this 
mailing list if you want to dig through archives, but just be aware that 
it is *not* sufficient to simply modify the [xyz]space:spacing attribute 
to be "regular__" as doing so will leave the irregular spacing 
information in the [xyz]space variable (`mincheader -data irregular.mnc` 
to see what I mean).

Cheers,
J


Simon Fristed Eskildsen wrote:
> Hi all,
> I just tried to run nu_evaluate and it crashes on mincmath:
> 
> nu_evaluate -keep -mapping test_N3.imp test.mnc test_N3.mnc
> [nu_evaluate] [---] [2007-03-29 14:51:06] 
> /gruppe/ad_mri/Opteron/pack/bin/evaluate_field -clobber -verbose -like 
> test.mnc test_N3.imp /var/tmp/nu_evaluate_16514//test_N3_field.mnc
> Not implemented yet in cache_volume_range_has_changed()
> Not implemented yet in cache_volume_range_has_changed()
> [nu_evaluate] [---] [2007-03-29 14:51:10] 
> /gruppe/ad_mri/Opteron/pack/bin/mincmath -clobber -verbose -copy_header 
> -zero -div test.mnc /var/tmp/nu_evaluate_16514//test_N3_field.mnc 
> test_N3.mnc
> Files /var/tmp/nu_evaluate_16514//test_N3_field.mnc and test.mnc have 
> different coordinate spacings (zspace)
> nu_evaluate: crashed while running mincmath (termination status=256)
> 
> The headers reveal that spacing is "irregular" on test.mnc while 
> "regular__" on test_N3_field.mnc
> I guess this is the problem that causes mincmath to complain.
> Is this expected behaviour of nu_evaluate? Do I need to make the spacing 
> in input minc file "regular__" ? If so, can I just edit the spacing 
> variable and remove the direction_cosines variable (which I guess is 
> only present in irregular spaced files)?
> 
> Thanks,
> Simon
> 
> 
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