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Bug 2808 - reading the last sample from a neuromag fif file returns 0

Status	CLOSED FIXED
Reported	2015-01-19 23:49:00 +0100
Modified	2019-08-10 12:40:48 +0200
Product:	FieldTrip
Component:	fileio
Version:	unspecified
Hardware:	PC
Operating System:	Mac OS
Importance:	P5 normal
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URL:
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Robert Oostenveld - 2015-01-19 23:49:36 +0100

this only happens if you read only the very last sample. If you read more, it will not be zero.

Jan-Mathijs Schoffelen - 2017-01-23 14:28:52 +0100

This is indeed the case, but the issue is more generic. If in general just a single sample of data is asked, ft_read_data returns all zeros. This can be traced back to line 213 in fiff_read_raw_segment. Data is only assigned to the output if picksamp>0, i.e. if more than a single sample is requested. Changing the '>' into '>=' would solve it. @Alex: do you see a principled reason to keep it '>' rather than to change it into '>='? (apart from the fact that it is a bit silly to ask only for a single sample of data...) If not, we probably would want to make this change also in the mne-matlab code.

Alexandre Gramfort - 2017-01-23 17:13:08 +0100

no objection to change this in the mne-matlab code can you open a pull request on github? thanks Alex

Jan-Mathijs Schoffelen - 2017-01-24 07:58:12 +0100

Sure, done.

Jan-Mathijs Schoffelen - 2017-01-24 09:23:16 +0100

Fixed in FT with PR 307.

Robert Oostenveld - 2019-08-10 12:34:38 +0200

This closes a whole series of bugs that have been resolved (either FIXED/WONTFIX/INVALID) for quite some time. If you disagree, please file a new issue on https://github.com/fieldtrip/fieldtrip/issues.