[FieldTrip] FW: problem with ft_prepare_singleshell

[Belluscio, Beth (NIH/NINDS) [E]]

Hi fellow fieldtrip users-
  I am currently using fieldtrip version 20110913 and have encountered a problem that wasn't there before.  After reslicing and segmenting my mri data (which was realigned to CTF format), I segmented the data using cfg.output = {'skullstrip' 'brain'} and seg = ft_volumesegment(cfg, mri).  I saved the resulting seg matrix. 
  Then, when I run ft_prepare_singleshell to generate my volumetric model (vol):

cfg = [];
vol = ft_prepare_singleshell(cfg, seg)

I get the following messages and error.



not downsampling anatomy
not downsampling brain
the call to "ft_volumedownsample" took 0 seconds and an estimated 0 MB
using the segmentation approach
Warning: adding /home/belluscb/nindsip/matlab/fieldtrip-20110913/external/spm8 toolbox to your
Matlab path 
using the segmented MRI
??? Reference to non-existent field 'seg'.

Error in ==> prepare_mesh_segmentation at 63
[mrix, mriy, mriz] = ndgrid(1:size(mri.seg,1), 1:size(mri.seg,2), 1:size(mri.seg,3));

Error in ==> ft_prepare_mesh at 124
  bnd = prepare_mesh_segmentation(cfg, mri);

Error in ==> ft_prepare_singleshell at 89
  vol.bnd = ft_prepare_mesh(cfg, mri);




If I use an old version of fieldtrip (20100505) that I had, and run the same command cfg = [];
vol = ft_prepare_singleshell(cfg, seg)  on the same seg matrix, it runs without a problem.  

I am not skilled enough (yet) at reading code to figure out what is not working with the recent version of fieldtrip.  
Can someone please assist me?

Thanks!
Beth.


Beth Belluscio MD-PhD
Clinical Fellow
Human Motor Control Section
NINDS, NIH
301-402-3495