parameter file and documentation

General information about brain-computer interfaces
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mbundesmann
Posts: 3
Joined: 15 Sep 2021, 13:59

parameter file and documentation

Post by mbundesmann » 16 Sep 2021, 05:21

Hello all,
I'm a German student and aim to record EEG data for a classification task using the BCI2000 software and I stumbled upon some questions on how to use it. To keep everything well structured I create a separate post for each question.

On my university laptop where I use bci2000 there are already some parameter files which I assume to be available as examples. So I went ahead and copied one that appeared to be a good match for my task and modified it. That is, I changed values for NumberOfSequences, PreRunDuration etc. following the documentation. Unfortunately I do not understand why there are often multiple values per variable where the in-file comment as well as the documentation state that there should be one(!) int. E.g. NumberOfSequences should be "number of sequence repetitions in a run" (see https://www.bci2000.org/mediawiki/index ... tationTask) with a "int" in front which makes me assume there should be a single value. However, there are multiple ints separated by a whitespace. Also, what does the "%" stand for? Is it a null value? The very same question applies to plenty other variables as well.
Similar obscurity for instance with Sequence: "In deterministic mode, a list of stimulus codes defining the sequence of presentations. In random mode, a list of integer stimulus frequencies". In the parameter file it says "intlist Sequence=" where I guess by trial and error that I also need to specify how many entries there are followed by the actual numbers for the frequencies. E.g. following the docs I would type "Sequence=10 10 10 10 10 10 10 10 " to have all 8 stimuli be presented 10 times each. However, this did not work. I had to add a preceeding "8" in front of these 10s but a I said this was nothing more but a guess. Am I overlooking something or is the documentation missleading here? Any help appreciated.

Cheers

mellinger
Posts: 1175
Joined: 12 Feb 2003, 11:06

Re: parameter file and documentation

Post by mellinger » 17 Sep 2021, 08:57

Hi,

parameter files are not supposed to be edited by hand. The Operator module provides a config dialog for this purpose.
If you prefer to edit parameter files by hand, the documentation you need is the one that describes the parameter format.
It is available here:
https://www.bci2000.org/mediawiki/index ... Definition

HTH,
Juergen

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