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Bug 792 - ft_preproc_polyremoval gives round off problems

Reported 2011-07-01 09:35:00 +0200
Modified 2011-07-06 16:38:26 +0200
Product: FieldTrip
Component: core
Version: unspecified
Hardware: PC
Operating System: Mac OS
Importance: P1 normal
Assigned to: Jan-Mathijs Schoffelen
Depends on:
See also:

Jan-Mathijs Schoffelen - 2011-07-01 09:35:54 +0200

when removing a simple linear trend (see faq why does my tfr look strange part II) the result is not a flat line, but has values ~10e-12. This is caused by the fact that the regression is being done by the '\' operator. I suggest to replace this by the numerically more stable (I tested it on the example above) inv(x'x)x

Jan-Mathijs Schoffelen - 2011-07-01 10:00:28 +0200

also made an additional change for further improvent. Rather than letting the basis functions run between 1 and nsamples, they now run from 0 to nsamples-1