Requires a bit of scripting to accomplish this.

Something along the lines of:

#!/bin/bash

cd FA

# Register new_extra_subj to everyone else and everyone else to new_extra_subj

for f in `$FSLDIR/bin/imglob *_FA.*` ;  do

$FSLDIR/bin/fsl_reg new_extra_subj_FA $f new_extra_subj_FA_to_${f} -e -FA

$FSLDIR/bin/fsl_reg $f new_extra_subj_FA ${f}_to_new_extra_subj_FA -e -FA

done

# Register new_extra_subj to itself as is done on tbss_2_reg -n

$FSLDIR/bin/fsl_reg new_extra_subj_FA new_extra_subj_FA new_extra_subj_FA_to_new_extra_subj_FA -e FA

You can accelerate this if you have multiple cores to run parallel threads... running for a month is a long time to wait

Best,

Danny Kim

On 2015-09-22, at 2:17 PM, Irina Anurova wrote:

Thank you for the answer.
Do you know how to accomplish this?

On Tue, Sep 22, 2015 at 8:30 PM, Daniel Kim <[log in to unmask]> wrote:

This should be possible.
The new subject needs to get non linear registration done to all other subjects, and then all other subjects need to non linear register to new subject.

Danny Kim
________________________________________
From: FSL - FMRIB's Software Library [[log in to unmask]] On Behalf Of Irina Anurova [[log in to unmask]]
Sent: Tuesday, September 22, 2015 6:55 AM
To: [log in to unmask]
Subject: [FSL] TBSS, reg to -n

Hi!
I am doing TBSS for a big group of kids. The script (tbss_2_reg -n) was running for a month. Now I would like to add one more subject. How to do it without rerunning the whole tbss_2_reg step?
Thank you!
Irina.