


FINDCLASSIFIER
identifies and validates a classifier of a BCI systems [1-3].
Several evaluation criteria are obtained [4]. Several Cross-validation
procedures are supported.
By default, a Trial-based Leave-One-Out-Method is used for Crossvalidation
MODE.Segments = class_times;
MODE.WIN = t_ref;
[CC,Q,TSD] = findclassifier(D,TRIG,Class,MODE,t_ref,TYPE);
Also this will work but its use is discouraged (it might become obsolete).
[CC,Q,TSD] = findclassifier(D,TRIG,Class,class_times,t_ref,TYPE);
An K-fold cross-validation can be applied in this way:
ng = floor([0:length(Class)-1]'/length(Class)*K);
[CC,Q,TSD] = findclassifier(D,TRIG,[Class,ng],...);
D data, each row is one time point
TRIG trigger time points
Class class information
class_times classification times, combinations of times must be in one row
t_ref reference time for Class 0 (optional)
TYPE determines the type of classifier (see HELP TEST_SC for complete list)
bthe default method is 'LD3'
CC contains the classifier and the validation results
Q is a list of classification quality for each time segment (as defined by 'class_times')
TSD returns the discrimination
Example:
[CC,Q,TSD]=findclassifier(d,find(trig>0.5)-257,~mod(1:80,2),reshape(1:14*128,16,14*8)');
see also: TRAIN_SC, TEST_SC, BCI4EVAL
Reference(s):
[1] Schl�l A, Neuper C, Pfurtscheller G
Estimating the mutual information of an EEG-based Brain-Computer-Interface
Biomedizinische Technik 47(1-2): 3-8, 2002.
[2] Schl�l A, Keinrath C, Scherer R, Pfurtscheller G,
Information transfer of an EEG-based Bran-computer interface.
Proceedings of the 1st International IEEE EMBS Conference on Neural Engineering, Capri, Italy, Mar 20-22, 2003
[3] Schl�l A, Lee FY, Bischof H, Pfurtscheller G
Characterization of Four-Class Motor Imagery EEG Data for the BCI-Competition 2005.
Journal of neural engineering 2 (2005) 4, S. L14-L22
[4] Schl�l A, Kronegg J, Huggins JE, Mason SG;
Evaluation criteria in BCI research.
(Eds.) G. Dornhege, J.R. Millan, T. Hinterberger, D.J. McFarland, K.-R.M�ler;
Towards Brain-Computer Interfacing, MIT Press, p327-342, 2007