I am trying to do DTIfit using the command line but it shows me the error " could not open matrix file bvecs. could not open matrrxi file bvals, Error:bvecs must be either 3XN or NX3" .

I try running it from GUI from which it runs fine, the problem is only with command line. 

The command line is as follows: 

 

dtifit --data=$1_eddy.nii.gz --mask=$1_brain_mask.nii.gz --bvecs=bvecs --bvals=bvals --out=dtifit_result

Your suggestions would be really helpful. 

Many thanks in advance. 

Regards, 

Nabin