Various ICA warnings and failures

arno arno at SALK.EDU
Fri Feb 23 18:02:34 CET 2007


The rank problem might be related to this issue on 64-bit machines

http://sccn.ucsd.edu/pipermail/eeglablist/2007/001675.html

Best,

Arno

Sameer Walawalkar wrote:
> Hi,
>
> This mail has 3  questions related to implementing ICA is fieldtrip.
>
> 1)
> I am now getting the following warnings from runica
> I am getting these messages while doing ICA on a datafile which contains
> sss MaxFiltered data (Elekta Neuromag).  When I visually inspect the
> independent components, they seem fairly identical to me. Their basic
> time
> structure seems to be same, just the scale is different.
>
> Prior to this, I had run ICA on the same datafile but with no
> MaxFiltering
> (or SSP projection for that matter).
>
> Final training data range: -0.00443438 to 0.00355995
> Computing the sphering matrix...
> Warning: Matrix is close to singular or badly scaled.
>          Results may be inaccurate. RCOND = 2.156998e-29.
>> In runica at 774
>   In componentanalysis at 331
> Starting weights are the identity matrix ...
> Sphering the data ...
> Beginning ICA training ...
> Data has rank 286. Cannot compute 307 components.
> Warning: Matrix is close to singular or badly scaled.
>          Results may be inaccurate. RCOND = 2.155705e-29.
>> In componentanalysis at 437
> total time in componentanalysis 160.6 seconds
>
> 2)
> binica on this datafile just hangs, after one learning, it sends nan
> and just hangs.
>
>
>
> 3)
> Fast ICA is giving me following errors
>>> compRR_One_fastica_sss = componentanalysis(cfg,dataRR_One);
> Warning: cannot determine whether the FASTICA toolbox is present
>> In fieldtrip/private/hastoolbox at 121
>   In componentanalysis at 176
> Warning: adding FASTICA toolbox to your Matlab path
>> In fieldtrip/private/hastoolbox at 145
>   In componentanalysis at 176
> Warning: Name is nonexistent or not a directory: fastica.
>> In path at 113
>   In addpath at 100
>   In fieldtrip/private/hastoolbox at 146
>   In componentanalysis at 176
> selecting 307 channels
> baseline correcting data
> concatenating data..............................
> concatenated data matrix size 307x120030
> starting decomposition using fastica
> Number of signals: 307
> Number of samples: 120030
> Calculating covariance...
> ??? Error using ==> componentanalysis
> call to fastica failed
>
> But when I do
>>> which fastica
> /mnt/condor2/sameer/KarmaCond/DataNeuroMagCondor2/MegSoftwareCondor2/FastICA_2.5/FastICA_25/fastica.m
>
>
>>> exist('fastica','file') (as seen in hastoolbox)
>
> ans =
>
>      2
>
>
> thanks,
> sameer
>
> p.s: I am currently running varimax on the sssed data and binica on
> the non sssed to see what happens.
>



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