Dear FSL experts,

I am trying to analyze my fMRI data using melodic:
Number of slices = 3
Matrix = 64x64
Number of volumes = 1024
TR = 0.3 sec

The system crashes after some calculations. The strange thing is that I have no problems when I only use the first 100, 200, or 500 volumes. However, when I try to use melodic with 700 volumes or more, I get the error:

######
Reading data file filtered_func_data  ...  done
Create mask ... done
Excluding voxels with constant value
Data size : 700 x 6064
Removing mean image ... done
Estimating data covariance ... done
Perform variance-normalisation ... done
Removing mean time course ... done
Starting PCA  ... done
Estimating the number of sources from the data (PPCA) ...
  Calling Smoothest: /usr/local/bin/fsl/bin/smoothest -d 700 -r filtered_func_data -m /fsl_analysis/700vol.ica/mask > /fsl_analysis/700vol.ica/smoothest

child killed: SIGABRT
#####

I am sure that the amount of memory is not a problem on the system I use (RAM = 1 GB, swap = 2.5 GB) and all my volumes are ok.

Is there possibly an upper limit to the number of volumes melodic can handle?

Thanks for any help,
Serge. 

Serge Rombouts, PhD
Functional MRI Laboratory
Vrije Universiteit Medical Center
Amsterdam, The Netherlands
Tel. +31 20 4440316
Fax +31 20 4444147
www.fmri.nl