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Bug 3251 - default conversion into 'cm'

Reported 2017-02-14 13:22:00 +0100
Modified 2019-08-10 12:43:54 +0200
Product: FieldTrip
Component: forward
Version: unspecified
Hardware: PC
Operating System: Mac OS
Importance: P5 major
Assigned to:
Depends on:
See also:

Gaetan - 2017-02-14 13:22:53 +0100

Fieldtrip seems to convert into 'cm' automatically if one input structure field is in 'cm'. This could create wrong source estimation when leadfield is computed using the new data.grad.tra field corrected. Maybe it would be good to set the defaults units conversion in 'm' ? For example when I run: cfg=[]; cfg.vol = vol; data.label; cfg.grid = grid; cfg.grad = data.grad; cfg.normalize = 'yes'; lf = ft_prepare_leadfield(cfg, data); if 'vol' , 'data.grad' are in meters ('m') but 'grid' in 'cm', fieldtrip will convert everything into 'cm'... then leading to wrong leadfield computation with the data.grad.tra field corrected. Keep me posted! Thanks in advance. Best, Gaetan

Thomas Hartmann - 2017-05-15 11:55:48 +0200

i would like to second this bug report as it can have detrimental effects on the data without raising any error message. i know that it would really break backward compatibility which is something to be avoided in general. however, i think it would be good to have some mean to at least turn on conversion to meters (or si units in general) or have the functions fail otherwise.

Jan-Mathijs Schoffelen - 2018-12-21 09:23:22 +0100

Hi gents, is this still an issue. If I recall well, Robert has been working on smoother unit handling, including correcting the tra-matrix for the planar gradiometers when units are changed...

Jan-Mathijs Schoffelen - 2019-03-27 13:09:29 +0100

OK, let's close this. I am not sure whether this is still an issue, and in absence of Gaeten's answer. Feel free to reopen constructively.

Robert Oostenveld - 2019-08-10 12:43:54 +0200

This closes a whole series of bugs that have recently been resolved (either FIXED/WONTFIX/INVALID). If you disagree, please file a new issue on