# mne\_do\_inverse\_operator

**URL:** <https://mne.discourse.group/t/mne-do-inverse-operator/720>\
**Category:** Mailing List Archive (read-only)\
**Tags:** list-archive\
**Created:** [May 1, 2014, 3:37pm UTC](https://mne.discourse.group/t/mne-do-inverse-operator/720 "2014-05-01T15:37:35Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [May 1, 2014, 3:37pm UTC](https://mne.discourse.group/t/mne-do-inverse-operator/720/1 "2014-05-01T15:37:35Z")

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Dear MNE Experts,

I suspect this is a question for Matti, but of course I'll be happy to get  
help from anyone. When I launch mne\_do\_inverse\_operator, it goes through  
the whole process, then at the very end it gives a "Segmentation fault".  
Oddly, I have a group of 20 participants, all analyzed the same way, but  
it only does this for one of them. I'd appreciate any help/insight you can  
give. Here's the full screen output, in case it helps:

wgraves at argus:~/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01\>  
mne\_do\_inverse\_operator --fwd $megdir/$rundir/${meas}-ico-4-fwd.fif  
--fixed --depth --megreg 0.1 --noisecov $megdir/$rundir/$cov

mne\_inverse\_operator version 2.33 compiled at Aug 14 2013 04:19:05

Compute the MNE inverse operator decomposition

Forward solution :  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword\_ave-ico-4-fwd.fif  
Noise covariance matrix :  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword-cov.fif  
Source covariance matrix : identity matrix  
Destination for the inverse operator data :  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword\_ave-ico-4-meg-fixed-inv.fif  
Include MEG data.  
Noise-covariance regularization (mag) : 0.10  
Noise-covariance regularization (grad) : 0.10  
Employ depth weighting.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;limit = 10.00  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;exponent = 0.80

Reading the forward solution....  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Read data for 306 MEG channels and 5112 sources  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Free source orientations.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The forward computation was performed in head coordinates.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Read 2 source spaces with a total of 5112 source locations  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Source spaces are now in head coordinates.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Channel description list matched with the composite forward  
solution matrix.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Local surface coordinate system forward matrix will be employed.

Loaded projection from  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword-cov.fif:  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;# 1 : planar-999--0.080-0.080-PCA-01 : 1 vecs : 204 chs MEG active  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;# 2 : axial-999--0.080-0.080-PCA-01 : 1 vecs : 102 chs MEG active  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;# 3 : planar-801--0.200-0.200-PCA-01 : 1 vecs : 204 chs MEG active  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;# 4 : axial-801--0.200-0.200-PCA-01 : 1 vecs : 102 chs MEG active

Read a full noise covariance matrix from  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword-cov.fif  
Picked appropriate channels from the sensor noise covariance matrix.  
MEG/EEG correlations omitted.  
Average noise-covariance matrix diagonals:  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Magnetometers : 170.14 fT reg = 0.10  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Planar gradiometers : 38.99 fT/cm reg = 0.10  
Noise-covariance regularized as requested.  
Projection applied to the covariance matrix.  
Decomposing the noise covariance...  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Estimated covariance matrix rank = 302 (0.00206112)  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;302 MEG and 0 EEG-like channels remain in the whitened data  
done.

Creating the depth weighting matrix...  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;204 planar channels  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;limit = 3613/5112 = 10.000623  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;scale = 2.06846e-07 exp = 0.8  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Picked elements from a free-orientation depth-weighting prior into  
the fixed-orientation one.  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Converted the forward solution into the fixed-orientation mode.  
Creating the source covariance matrix:  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Depth-weighting applied.  
done

Applying linear projection to the forward solution...done  
Whitening the forward solution...done  
Scaling the source covariance...done  
Decomposing...  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Applying a priori source weighting to the forward solution...done  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Transpose...done  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;SVD...done  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;largest singular value = 0.171679  
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;scaling factor to adjust the trace = 25.2724 (nchan = 306 nzero = 4)  
done

Writing the solution to  
/home/wgraves/data/ld\_fmri/data/4803/freesurf/4803/MEG/run03\_lexdec01/run03\_xtraClean\_0.1\_40Hz\_word\_nonword\_ave-ico-4-meg-fixed-inv.fif...Segmentation  
fault  
Inverse operator decomposition failed (see above)

Thanks in advance,  
Will

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<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/free1/uploads/mne/original/1X/85cc6bd2b69cb698a166dc6d880fb550510d0144.jpeg) [@system](https://mne.discourse.group/u/system)\
**Post date:** [May 1, 2014, 3:51pm UTC](https://mne.discourse.group/t/mne-do-inverse-operator/720/2 "2014-05-01T15:51:47Z")

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Hi,

How much free disk space is there?

df -h $megdir/$rundir/

HTH  
D
