warning for ctf-users

[jan-mathijs schoffelen]

Dear all,

I came across a bug in the code which may affect people who use
FieldTrip to analyze CTF-data. The function ft_denoise_synthetic,
which can be used to convert the data to higher (or lower) order
gradients did not work as it was supposed to. Rather than applying the
balancing matrix to the data it applied the inverse of the balancing
matrix to the data. This is wrong, and most likely results in the data
becoming more 'noisy', rather than less noisy. It is not exactly clear
since when this bug exists and it may be worthwhile to critically re-
evaluate data which have been processed with ft_denoise_synthetic.
We sincerely apologize for any inconvenience caused.

Best wishes,

Jan-Mathijs

PS: Of course the correct version of the file will be available for
download on the ftp-server as of tomorrow.


Dr. J.M. (Jan-Mathijs) Schoffelen
Donders Institute for Brain, Cognition and Behaviour,
Centre for Cognitive Neuroimaging,
Radboud University Nijmegen, The Netherlands
J.Schoffelen at donders.ru.nl
Telephone: 0031-24-3668063

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