adjeta(eta, rmse)

function new_eta = adjeta(eta, rmse)

% ADJETA Adjust learning rate eta in SD according to history of RMSE.



inc_rate = 1.01;

dec_rate = 0.99;

leng = length(rmse);

if leng < 5,

	new_eta = eta;

	return;

end



diff_rmse = diff(rmse(leng-4:leng));



% Four consecute downs

if all(diff_rmse<0)

	new_eta = eta*inc_rate;

% Four consecute ups

%elseif all(diff_rmse>0)

%	new_eta = eta*dec_rate;

% down, up, down, up

%elseif diff_rmse(1)<0 & diff_rmse(2)>0 & diff_rmse(3)<0 & diff_rmse(4)>0,

%	new_eta = eta*dec_rate;

% up, down, up, down

elseif diff_rmse(1)>0 & diff_rmse(2)<0 & diff_rmse(3)>0 & diff_rmse(4)<0,

	new_eta = eta*dec_rate;

else

	new_eta = eta;

end