[Eeglablist] How to make an ICA run in less than a week?

[Makoto Miyakoshi]

Dear James and Jason,

First of all, your sampling rate seems too high. The more datapoints
you submit to ICA, slower the process is. Unless you have a reason to
maintain the high sampling rate, why don't you downsample it to 250Hz
or 500Hz?

Another reason I can think of is that your data could be abnormal (in
terms of rank?) When I ran informax ICA on my EEG-fMRI data which was
preprocessed but still had large residual artifacts, ICA was
surprisingly slow.

Any comment please, Jason?

Makoto

2012/7/5 James Schaeffer <schaefj3 at gmail.com>:
> Dear eeglablist,
>
> I am running ICAs on 10 minutes of Biosemi EEG data, collected from 128
> channels, and sampled at 2048 Hz. However, the ICAs have been running for a
> few days without much progress. Two computers have 8G RAM and an Intel(R)
> Xeon(TM) CPU 2.80GHz. One has been running an ICA for 6 days and is on step
> 33; the other, for 4 days, and is on step 28. Another computer has 12G RAM
> and an Intel(R) Xeon(R) CPU 5110 @ 1.60GHz; it has been running for 3 days
> and is on step 60. All are running openSUSE 12.1 (x86_64), with eeglab
> version 10.2.2.4b. The 'free' command indicates that they are not using any
> swap space.  Should it be taking this long?  Is it possible that we have
> more than the one copy of the data in ram or that Matlab or Eeglab has
> placed something else in ram, or is busy with other processes? Is there
> anything I can do to speed up this process? Any help would be greatly
> appreciated.
>
> Thanks in advance,
> James
>
>
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-- 
Makoto Miyakoshi
JSPS Postdoctral Fellow for Research Abroad
Swartz Center for Computational Neuroscience
Institute for Neural Computation, University of California San Diego