set x = `cat bvecs | awk '{if (NR==1) print}'`
set y = `cat bvecs | awk '{if (NR==2) print}'`
set z = `cat bvecs | awk '{if (NR==3) print}'`

@ k = 1
while ( $k <= `head -1 bvecs|wc -w` )
  echo $x[$k] $y[$k] $z[$k]
  @ k = $k + 1
end

I'd make sure though dcm2nii doesn't L-R flip the gradient vectors, I think there was a thread recently that suggested it might.

On Wed, 7 Aug 2013, Salil Soman wrote:

Hi,
I have dicoms that I turn to nifti using dcm2nii (with the default settings plus anonymization option turned on [-a
y]). The bvec files it generates by default are 3 rows by n columns (where n is b0 number + directions). I am under
the impression tracula requires this to be converted to a n row by 3 column file. 1) is this correct, 2) is there a
preferred way to perform this transformation on linux systems?

Thanks you,

-Sal

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