function [E, Eimu] = wcf_snn(X, net, data)%WCF_SNN Weighted cost function.%%Syntax%%  1. [cost, Eimu] = wcf_snn(net, wcfdata)%  2. [cost, Eimu] = wcf_snn(X, net, wcfdata)%  3. costfcn_struct = wcf_snn('pdefaults')%%Description%%  WCF_SNN computes the following cost function:%%  cost(y, t) =  sum_{ \{i, \mu | \Delta_{i\mu} = 1\} } %                   a_i g_{\mu} e^i(y_{i\mu}, t_{i\mu})%%   with:%    i            - output index%    \mu          - pattern index%    a_i          - output weight%    g_{\mu}      - pattern weight%    e^i          - error function for output i%    y_{i\mu}     - prediction for output i, pattern \mu.%    t_{i\mu}     - target for output i, pattern \mu.%   \Delta_{i\mu} - parameter controlling over which outputs for%                   which patterns the summation is done%%  1. WCF_SNN(net, wcfdata) takes%   net     - a net_struct with error function WCF_SNN.%   wcfdata - a wcfdata_struct containing input/output patterns.   %  and returns%   cost    - the total weighted cost.  %   Eimu    - the weighted error for each (output, pattern) pair.%%  2. WCF_SNN(X, net, wcfdata) takes%   X       - additional vector with connection weights and biases,%             which are used to compute the cost instead of the%             connenction weights and biases in 'net'.%%  3. The field 'costFcn' of 'net' must contain a stucture with the cost%   function parameters. The default parameters can be set with%%   net = set_net_costfcn_snn(net, wcf_snn('pdefaults'));%%  (NL = #outputs)%%Example%%   MU = 5;%   P = rand(2, MU);%   T = rand(1, MU); %   gmu = [1 2 2 1 1];%   Delta = [1 0 1 0 1];%   wcfdata = wcfdata_struct_snn(P, T, gmu, Delta)%   net = net_struct_snn([2 4 1], {'tansigtf_snn', 'lintf_snn'},'trainlm_snn');%   wcf_snn(net, wcfdata)%% See Also%%   NET_STRUCT_SNN, WCF_STRUCT_SNN, WCFDATA_STRUCT_SNN%if (isstr(X))   switch lower(X)     case 'deriv',          E = 'dwcf_snn';     case '2deriv',          E = 'd2wcf_snn';     case 'argmin',          E = 'argmin_wcf_snn';     case 'pdefaults',	  E = wcf_struct_snn;     otherwise,          error('Unrecognized code.')   end    returnendif (nargin == 2)             % wcf_snn(net, data)   data = net;   net = X;elseif (nargin == 3)         % wcf_snn(X, net, data)   net = setx_snn(net, X);else   error('Incorrect number of input arguments');end% special: if isfield(data.Y) then ignore network outputs and compute% cost from E(data.Y, data.T);if isfield(data, 'Y')   y = data.Y;else   y = simff_snn(net, data);endg = getg_snn(net, data);errf = net.costFcn.fn;[E, Eimu] = wef_snn(y, data.T, g, errf);