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Bug 3350 - Error in sLoreta square root matrix

Reported 2017-09-19 20:45:00 +0200
Modified 2017-11-09 17:34:06 +0100
Product: FieldTrip
Component: inverse
Version: unspecified
Hardware: All
Operating System: All
Importance: P5 major
Assigned to: Ricardo Bruña Fernández
Depends on:
See also:

Ricardo Bruña Fernández - 2017-09-19 20:45:19 +0200

In the sLoreta code (inverse/ft_sloreta.m), line 255 in the current version, the code reads: filt(ii,:) = pinv(sqrt(lf(:,ii)' * invG * lf(:,ii))) * lf(:,ii)' * invG; Pascual-Marqui in arXiv 0710.3341 equation 15 uses the inverse square root of the symmetric matrix. Right now the code is calculating the inverse of the matrix formed by the square root of each element. The code, thus, should read: filt(ii,:) = pinv(sqrtm(lf(:,ii)' * invG * lf(:,ii))) * lf(:,ii)' * invG; This completely perverts the calculated spatial filter.

Jan-Mathijs Schoffelen - 2017-11-09 17:34:06 +0100

Please suggest a fix through github. Thank you.