OpenViBE forum

Hi,

I guess the selected row and column are given as the output of the two voting classifiers at the end of the online p300 scenario that comes with OpenViBE.

Best regards,
Dieter Devlaminck

Hi, I don't exactly understand you question. The default parameters of the box are just the train trigger, the number of cross-validation folds and the number of inputs (representing the features for each class). You can change them to whatever you want. Just make sure that the trigger you specify t...

Hi, You need to take all the left trials as class one and all the right/up trials as class two. You can achieve this in the training scenario by using the multiplexer box that multiplexes the data from the right and up trials into one stream. To the classifier trainer this will look like it is data ...

Hi, The train trigger should indicate the end of the experiment at which all features have been collected and thus computation of the parameters can begin. The value of this trigger depends on what stimulus you used to indicate the end of your experiment in the file you have save during acquisition....

You could also try to use the matlab box and use matlab to plot the things you want to plot. Or if you do not have matlab, maybe there is a similar python box? Although I can not seem to find a python box, I definitely heard that someone developed that? Does anyone know the person who did? EDIT: Ok ...

Hi, We want to use the matlab filter box for an experiment, but we need to do some time consuming initialization before we can start processing. The initialize function that one specifies in the matlab filter box settings actually seems to refer to a function that processes the header, so it complai...

Hi Hi, I am working on a project for school and I first got the normal headset they first bought. Now I got the research SDK but still have the normal headset with it. Will I be able to work with that one too or do I need the dev headset? I thought the headsets are the same, but I guess that is a qu...

Hi, Sorry, maybe we missed this post. I think lbonnet refers to the log or the output on the comand line while compiling openvibe. I'm not sure where it is saved, but you can catch its output by compiling with the following command "win32-build.cmd > compile_log.txt". Somewhere it should indicate li...

Hi, I'm not sure if I can be of any help, but in the past I had similar problems on XP where it could not find certain libraries. So to track down the problem you could check the following. It does not seem to find the expat library. I'm not sure how this is possible (although I managed to do this i...

“Plugin code cause crash 1(0x1) time(s) [name: LDA classifier-GPL] [class identifier: 0xd7183fe7, 0xbd74f298] [location::process callback]”??? I do not actually know what caused this, but maybe you can post your log files in the dist\log directory so the developers can take a look (if it contains m...

I’m do not quite understand what are the differences between the training scenario for P300 speller and the online scenarios? The layout looks very different, however, the differences on functionality are not clear to me. In the online scenario one has to average the EEG for each row and column sti...

SVM classifier was trained for 12 sessions and the average accuracy was 83.33%. However, when I used the online scenario, I didn’t get any letter right :cry: all targets were wrong. Did you find the same problems? How can I improve the performance? The P300 experiment records unbalanced data, meani...

Hi, 1) Source Codes of boxes are available to us for modification or not. Means if we need to modify the functioning of some box how can we do that? Yup, this is indeed possible. You can find most information here For building and downloading, see the corresponding section on "Source code handling" ...

Hi, At the moment, I do not know of any existing scenario to recognize emotions based on incoming EEG signals, but there are of course several signal processing boxes in OpenViBE which should enable you to create a scenario that does the necessary preprocessing and classification of the EEG signal t...

Hi, In my case it is under Tools->Matlab filter. But if it is not there you will probably need to compile the package from the sources. More info on how to do that can be found here . To compile the Matlab filter box, you will probably need to uncomment the following rule echo %OpenViBE_plugin_matla...