f@2: function [features] = extract_features(experiment, N, options)
f@2: 
f@2:   switch(experiment)
f@2: 
f@2:     case 'mfcc_740ms'
f@2:       
f@2:       filters = filter_bank(N, options.filt1_opt);
f@2:       features = {@(x)(feval(@(x)(...
f@2:         [x;...
f@2:         circshift(x, [0 +1]); ...
f@2:         circshift(x, [0 -1])]),...
f@2:         format_scat(log_scat(...
f@2:           spec_freq_average(x, filters, options.sc1_opt)))))};
f@2:             
f@2:     case {'time_scat_l1', 'time_scat_l2', 'time_scat_l3'}
f@2:       
f@2:       Wop = wavelet_factory_1d(N, options.filt1_opt, options.sc1_opt);
f@2:       features = {@(x)(format_scat(log_scat(...
f@2:         renorm_scat(scat(x, Wop)))))};
f@2: 
f@2:     case {'time_freq_scat_l2', 'time_freq_scat_l2_adap_q1'}
f@2: 
f@2:       Wop1 = wavelet_factory_1d(N, options.filt1_opt, options.sc1_opt);      
f@2:       fWop1 = wavelet_factory_1d(...
f@2:         128, options.ffilt1_opt, options.fsc1_opt);
f@2: 
f@2:       scatt_fun1 = @(x)(log_scat(renorm_scat(scat(x, Wop1))));
f@2:       fscatt_fun1 = @(x)(func_output(@scat_freq, 2, scatt_fun1(x), fWop1));
f@2:       feature_fun1 = @(x)(format_scat(fscatt_fun1(x)));
f@2: 
f@2:       switch(experiment)
f@2: 
f@2:         case 'time_freq_scat_l2'
f@2: 
f@2:           features = {feature_fun1}
f@2: 
f@2:         case 'time_freq_scat_l2_adap_q1'
f@2: 
f@2:           Wop2 = wavelet_factory_1d(N, options.filt2_opt, options.sc2_opt);
f@2:           fWop2 = wavelet_factory_1d(...
f@2:             32, options.ffilt2_opt, options.fsc2_opt);
f@2:           
f@2:           scatt_fun2 = @(x)(log_scat(renorm_scat(scat(x, Wop2))));
f@2:           fscatt_fun2 = @(x)(func_output(@scat_freq, 2, scatt_fun2(x), fWop2));
f@2:           feature_fun2 = @(x)(format_scat(fscatt_fun2(x)));
f@2: 
f@2:           features = {feature_fun1, feature_fun2};
f@2: 
f@2:       end  
f@2: 
f@2:     for k = 1:length(features)
f@2:       fprintf('testing feature #%d...', k);
f@2:       tic;
f@2:       sz = size(features{k}(randn(N, 1)));
f@2:       aa = toc;
f@2:       fprintf('Ok (%.2fs) (size [%d, %d])\n', aa, sz(1), sz(2));
f@2:     end
f@2: 
f@2:     otherwise
f@2:         error(['Unknown experiment ', experiment, '. Aborting']);
f@2:   end
f@2: 
f@2: end