I am having difficulty in understanding the use of CSP for EEG signal feature extraction and subsequently. Since I am using two classes, this query will be restricted to it.
In essence CSP requires 2 classes of trial data, i.e C1, the covariance matrix for class 1, and C2, the covariance matrix for the second class, for calculating W, the spatial filter matrix, using eigenvectors/eigenvalues. Following the procedure the log variance is calculated. This is useful during the training phase.
However when I conduct a trial, it will belong to either C1 or C2. I cannot calculate the CSP for this particular trial.
How are features of the EEG Signal extracted then?
I am not too sure if this is the correct forum for asking this question. I apologise in advance. Please suggest the correct forum for the same.