Thanks, Saad. I was running probtrackx through Matlab on parallel mode (malabpool and parfor), and it seems that the operating system Linux is having problems executing probtrackx in parallel, only speculating. The loop is now running as a normal for loop and it seems to be working fine. Regarding --opd option, it is indeed included.

Many thanks for your help, much appreciated.

From: FSL - FMRIB's Software Library [[log in to unmask]] on behalf of Saad Jbabdi [[log in to unmask]]
Sent: Friday, January 06, 2012 6:04 AM
To: [log in to unmask]
Subject: Re: [FSL] probtrackx question

Hi Farras
We need more details about what you have done to be sure what's going on.
One possibility is you may have forgotten the "--opd" option for those probtrackx calls that did not produce results?

Saad
--

Farras Abdelnour
http://sacklerinstitute.academia.edu/FarrasAbdelnour 
Imaging Data Evaluation and Analytics Laboratory (IDEAL)
Department of Radiology | Weill Cornell Medical College
515 E. 71st St., S-125 | New York, NY 10065
email: [log in to unmask]
http://ideal-cornell.com