test_trca.m

function results = test_trca(eeg, model, is_ensemble)
% Test phase of the task-related component analysis (TRCA)-based
% steady-state visual evoked potentials (SSVEPs) detection [1].
%
% function results = test_trca(eeg, model, is_ensemble)
%
% Input:
%   eeg             : Input eeg data 
%                     (# of targets, # of channels, Data length [sample])
%   model           : Learning model for tesing phase of the ensemble 
%                     TRCA-based method
%   is_ensemble     : 0 -> TRCA-based method, 
%                     1 -> Ensemble TRCA-based method (defult: 1)
%
% Output:
%   results         : The target estimated by this method
%
% See also:
%   train_trca.m
%
% Reference:
%   [1] M. Nakanishi, Y. Wang, X. Chen, Y. -T. Wang, X. Gao, and T.-P. Jung,
%       "Enhancing detection of SSVEPs for a high-speed brain speller using 
%        task-related component analysis",
%       IEEE Trans. Biomed. Eng, 65(1): 104-112, 2018.
%
% Masaki Nakanishi, 22-Dec-2017
% Swartz Center for Computational Neuroscience, Institute for Neural
% Computation, University of California San Diego
% E-mail: masaki@sccn.ucsd.edu

if ~exist('is_ensemble', 'var') || isempty(is_ensemble)
    is_ensemble = 1; end

if ~exist('model', 'var')
    error('Training model based on TRCA is required. See train_trca().'); 
end

fb_coefs = [1:model.num_fbs].^(-1.25)+0.25;

for targ_i = 1:1:model.num_targs
    testdata = squeeze(eeg(targ_i, :, :));
    for fb_i = 1:1:model.num_fbs
        testdata_tmp = filterbank(testdata, model.fs, fb_i);
        for class_i = 1:1:model.num_targs
            traindata =  squeeze(model.trains(class_i, fb_i, :, :));
            if ~is_ensemble
                w = squeeze(model.W(fb_i, class_i, :));
            else
                w = squeeze(model.W(fb_i, :, :))';
            end
            r_tmp = corrcoef(testdata_tmp'*w, traindata'*w);
            r(fb_i,class_i) = r_tmp(1,2);
        end % class_i
    end % fb_i
    rho = fb_coefs*r;
    [~, tau] = max(rho);
    results(targ_i) = tau;
end % targ_i