[FieldTrip] What are the units output by ft_freqanalysis_tfr?

[Aaron Schurger]

Hi, Eelke,
Thanks for your reply. I think that might explain it. When I step
through my code, I see that the units are as expected for MEG in the
output from ft_freqanalysis, so it must be something after that stage
that is changing.
Thanks for the tip!
Best wishes,
Aaron

On Tue, Jun 11, 2013 at 9:58 AM, Eelke Spaak <eelke.spaak at donders.ru.nl> wrote:
> Hi Aaron,
>
> How are you plotting the data? If you are using
> ft_single/multi/topoplotTFR, did you use baseline correction
> (cfg.baseline = 'yes' or [begin end])? If you use cfg.baselinetype =
> 'relative' or cfg.baselinetype = 'relchange', data plotted will
> typically be on the order of 10e-1. It represents ratio vs baseline
> ('relative') or relative change vs baseline ('relchange').
>
> If you did not specify baseline correction, then there is something
> else going on. In any case, ft_freqanalysis does not explicitly
> transform/normalize units; it does not care about them.
>
> Best,
> Eelke
>
> On 10 June 2013 18:11, Aaron Schurger <aaron.schurger at gmail.com> wrote:
>> Hi,
>> I am preparing figures for a paper, one of which is a time-frequency
>> plot of the output from ft_freqanalysis (using the tfr method). The
>> units of the data going in were on the order of 10e-11 or smaller (MEG
>> data), but the units on the color (power) axis of the plot are on the
>> order of 10e-1. Are the units normalized by default when you use
>> ft_freqanalysis? If not then what are the units? The help on these
>> functions was short on this kind of detail.
>> Thanks!
>> Aaron Schurger
>>
>> --
>> Aaron Schurger, PhD
>> Post-doctoral researcher
>> INSERM U992 / NeuroSpin
>> CEA - Saclay, France
>> +33-1-69-08-66-47
>> aaron.schurger at gmail.com
>> http://www.unicog.org
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-- 
Aaron Schurger, PhD
Post-doctoral researcher
INSERM U992 / NeuroSpin
CEA - Saclay, France
+33-1-69-08-66-47
aaron.schurger at gmail.com
http://www.unicog.org