OpenViBE forum

Hi,
I want to plot p300 auditory signal. I have a auditory signal with two different tone : regular(t1) and rare(t2) tone. I want to do

a)Want to add epochs with t1=e1
b)Want to add epochs with t2=e2
c)Want to subtract e3=e1-e2
d)Plot p300(e3)

Help please . See the attached eeg file in csv and tone.
Rafia

email: akhter.rafia1@gmail.com

Hi,
If I understood, you wan't to substract and plot two differnt epochs.
In openvibe boxes already writen you can make process on current epoch, if you wan't to work with previous epochs, I think it's better to read your signal and make your process outside OpenViBE (with Python for example) and you make a new signal file with your substract and next plot to OpenViBE.
If you wan't to make this during online acquistion you can write a box who stack your epochs in two stack and make the output you wan't your e3. Take care if you wan't to stack too much informations release or limite the number of epochs.
Personally, I would make a scenario that uses a stream switch that will have 3 output (e1, e2, epoch useless). Then I would encode a box with two input (e1, e2) and I will have an e3 output and I remove epoches become useless as and when.
Thibaut

Thanks.