Hi
looks like smoothest isn't happy, can you please try
/usr/local/bin/fsl/bin/smoothest -d 700 -r filtered_func_data -m
/fsl_analysis/700vol.ica/mask
In cases like yours where the number of voxels is relatively small
compared to the number of time points you might even want to switch off
the automatic dim. estimation - I wouldn't necessarily assume that it
gives reliable estimates - you can do this from the GUI or usingthe -d
option from the command line
ta
Christian
Rombouts, S.A.R.B. wrote:
> 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_
>
--
Christian F. Beckmann
Address: Oxford University Centre for Functional
Magnetic Resonance Imaging of the Brain,
John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
Email: [log in to unmask] http://www.fmrib.ox.ac.uk/~beckmann/
Phone: +44(0)1865 222782 Fax: +44(0)1865 222717 Mob: +44(0)7811 189123
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