Hi all SPM,
I have been reprocessing some fMRI data with SPM5. AFAIK, my data stays
the same with only two differences with the last preprocessing and
anaylisis time: I have unwarped the images (realign+unwarp) and I have
used SPM5 instead of SPM2 (I thought it was time to give SPM5 a good try
so I wanted to re-do everything with the new software).
When I run the estimation step I get the following error:
> Temporal non-sphericity (over voxels) : ...REML estimation
> ReML Block - 1
> ReML Iteration : 1
> ...5.826509e+003
> ReML Iteration : 2
> ...1.079337e+001
> ReML Iteration : 3
> ...8.316548e-002
> ReML Block - 2
> ReML Iteration : 1 ...NaN
> Warning: Matrix is singular to working precision.
> > In spm_reml at 87
> In spm_spm at 855
> In spm_config_fmri_est>run_est at 382
> In spm_jobman>run_struct1 at 1379
> In spm_jobman>run_struct1 at 1387
> In spm_jobman>run_struct1 at 1387
> In spm_jobman>run_struct at 1346
> ??? Error using ==> svd
> NaN or Inf prevents convergence.
>
> Error in ==> pinv at 23
> [U,S,V] = svd(A,0);
>
> Error in ==> spm_reml at 92
> % E-step: conditional covariance cov(B|y) {Cq}
>
> Error in ==> spm_spm at 855
> [Vp,hp] = spm_reml(Cy(q,q),Xp,Qp);
>
> Error in ==> spm_config_fmri_est>run_est at 382
> SPM = spm_spm(SPM);
I have gone to my 'old' SPM2 preprocessed data and I have estimated the
design with the 'old' data again. Estimation has gone well this time.
So I guess that there is a problem about unwarping that could be
generating different data that could make SPM crash. Do you have any
experience about unwarp & not being able to estimate your SPM design??
Any thoughts about this problem?
Thanks a lot!!
Juan
--
________________________________________________________
Juan J. Lull Noguera - jualulno_at_upvnet.upv.es
[MI - Medical Imaging Area]
BET - Bioengineering, Electronics and Telemedicine Group
UPV - Politechnical University of Valencia - Spain
________________________________________________________
[IM - Área de Imagen]
BET - Grupo de Bioingeniería, Electrónica y Telemedicina
UPV - Universidad Politécnica de Valencia
________________________________________________________
"My definition of an expert in any field is a person who
knows enough about what's really going on to be scared."
- PJ Plauger
|