2016160046 김유현
-코드-
%%% N_variable_book.m %%%
clear;
N=10; w = 0.5*ones(1,N); eta = 0.7;
E = inline('0.5*sum((w-[1:N]/N).^2)','w','N');
dEdw = inline('xx-tt','xx','tt');
fprintf('W(1) = (%f,%f,%f,%f,%f,%f,%f,%f,%f,%f), E(W(1)) = %f \n',...
w,E(w,N));
tol = 1.0e-3;
cost1 = E(w,N);
err = 2*tol;
k = 1;
while err > tol
for i = 1:N
new_w(i) = w(i) - eta*dEdw(w(i),i/N);
end
w = new_w;
fprintf('W(%d) = (%f,%f,%f,%f,%f,%f,%f,%f,%f,%f), E(W(%d)) = %f \n',...
k+1,w,k+1,E(w,N));
cost2 = E(w,N);
err = abs(cost2 -cost1);
cost1 = cost2;
k = k+1;
end
-실행결과-
>> N_variable_book
W(1) = (0.500000,0.500000,0.500000,0.500000,0.500000,0.500000,0.500000,0.500000,0.500000,0.500000), E(W(1)) = 0.425000
W(2) = (0.220000,0.290000,0.360000,0.430000,0.500000,0.570000,0.640000,0.710000,0.780000,0.850000), E(W(2)) = 0.038250
W(3) = (0.136000,0.227000,0.318000,0.409000,0.500000,0.591000,0.682000,0.773000,0.864000,0.955000), E(W(3)) = 0.003443
W(4) = (0.110800,0.208100,0.305400,0.402700,0.500000,0.597300,0.694600,0.791900,0.889200,0.986500), E(W(4)) = 0.000310
W(5) = (0.103240,0.202430,0.301620,0.400810,0.500000,0.599190,0.698380,0.797570,0.896760,0.995950), E(W(5)) = 0.000028