help with aic and bic

Hello,

I am using the following code to find the order of an autoregressive(AR) process.

But I got same answers for both AIC and BIC. Is there anything wrong?

ptest = arxstruc(xt(1:T/2), xt((T/2)+1:T), pmaxvec);

arorder_aic  = selstruc(ptest,'AIC');    % estimated AR order - p hat (by aic criterion)

arorder_bic  = selstruc(ptest,'BIC');

Thanks

[Adam]

Do you expect the order to be different for the inputs you gave?

Are you actually getting the AIC and BIC evaluations out or just the ordering resulting from these? The latter may quite conceivably be the same despite the former being different for some inputs.