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Matlab

function [y,e,ytrace,W,V,U]=dim_activation_recurrent(W,xtrace,y,iterations,V,U)
[n,m]=size(W);
[nInputChannels,z]=size(xtrace);
%set parameters
epsilon1=1e-5;
epsilon2=1e-3;
if nargin<3 || isempty(y),
%initialise prediction neuron outputs
y=zeros(n,1,'single');
end
if nargin<4, iterations=25; end
if nargin<5 || isempty(V),
%set feedback weights equal to feedforward weights normalized by maximum value
V=bsxfun(@rdivide,W,(1e-9+max(W,[],2)));
U=V;
end
for t=1:iterations
%define inputs: temporally changing values are used (if these are provided), and
%previous output values are copied to provide recurrent input
x=xtrace(:,min(t,z));
x(nInputChannels+1:nInputChannels+n)=y;
%update error and prediction neuron responses
e=min(1,x)./(epsilon2+(V'*y));
y=(epsilon1+y).*(W*e);
%record activation history - if required
if nargout>2
ytrace(:,t)=y;
end
%perform learning at every step - if required
if nargout>3
[W,V]=dim_learn(W,V,y,e);
end
if nargout>5
U=dim_learn_feedback(U,y,x);
end
end