[Eeglablist] Why do I have to duplicate the labels used in classification process?

Sahar Selim sahar.soussa at gmail.com
Wed Aug 12 02:32:19 PDT 2015


Dear All,

I'm using the BCI Competition dataset IV 2a. I'm working on Left & right
hand movement.  I extracted data of channels (Fz,Cz,Pz).
I filtered data [8-30], then normalized it. Then, I calculated the common
spatial patterns of the training dataset using the CSP.m of the Biosig
toolbox
I want to use the "train_sc" to classify my data.

My question is why do I need to duplicate the labels of each event?

ex:
for each right hand event (750 samples) I must have 750 label = 1
for each left  hand event (750 samples) I must have 750 label = 2

labels = repmat(classlabel’,n,1)’;   %where n is the number of samples/event
CC = train_sc(features,labels,'LDA');

Does that mean that classification is done on samples rather than events?
Is each sample classified independently?!!!

The results I got are very disappointing. I've tried many classifiers but
the best accuracy I got was 0.5
I need to know what I'm doing wrong.

I've read too much on CSP feature extraction & classification of the eeg
signals, but still I feel that I'm missing many things :(
Any help please.

Best Regards,
Sahar Selim
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