motor-imagery scenario: classifier training doesn't stop

Working with OpenViBE signal processing scenarios and doing scenario/BCI design
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pwierzgala
Posts: 22
Joined: Tue Nov 26, 2013 3:43 pm

motor-imagery scenario: classifier training doesn't stop

Post by pwierzgala »

I wanted to reproduce motor-imager scenario so I started to load xmls one by one to designer and run them according to description. I found a couple of problems on my way and I would like to ask you for opinion.

In motor-imager-bci-1-acquisition.xml Graz visualization finishes but the visualization window doesn't close. It remains black and the output file keeps growing in size. In order to finish this scenario I had to click stop button.
Question: I expected that the visualisation will be automatically closed and I'll be given some message like info, success or error. Is stopping designer the right way to finish this scenario?

In motor-imagery-bci-2-classifier-trainer.xml I set the path to the output file from previous scenario (in generic stream reader) and path to the configuration file in Classifier trainer and after that I run the scenarion. The problem is that it never finishes and no configuration file is genearated. It seemd that the trining should finish when classifier trainer finds OVTK_GDF_End_Of_Session marker. My futher investigation brought me to the source code of *.lua script used in the previous scenario to display Graz visualization. At the end of it I found that it outputs OVTK_StimulationId_ExperimentStop after displaying all trails. So I've changed the train trigger value in classifier trainer properties and I've managed to generate configuration file.
Question: I thought that because it's a standard scenario provided with open vibe all settings should be ready to use. It makes me wonder that I've did something wrong. Could you give my your opinion about steps I've done?

jtlindgren
Posts: 775
Joined: Tue Dec 04, 2012 3:53 pm
Location: INRIA Rennes, FRANCE

Re: motor-imagery scenario: classifier training doesn't stop

Post by jtlindgren »

Hi Pwierzgala,

About the first question, if there is no player controller box in the scenario, which is the situation in this case, the scenario does not stop automatically and you need to do it manually. We should add this controller to those scenarios where it's currently missing.

The second problem is clearly a bug. The script of the first scenario writes a different token to the file than what's specified in the trainer box configuration of the other scenario. These tokens should be the same.

Thank you for the report,
Jussi

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