I'm using ARMA to simulate and predict a series of data. "i" represens the number of pre-sample for ARMA estimate and "j" represents the number of estimation sample for ARMA estimate.
The absolute percentage errors (APE) are calculated for different numbers of pre-sample and estimate sample data.
I want to stop the loop when the APE is small than 0.05. I used break function, but it won't stop until it finishes all the loops (till i=60, j=60)
EstMdl = estimate(Mdl,Y_out((i+1):(i+j)),'Y0',Y_out(1:i));
gasforecast = forecast(EstMdl,180-i-j,'Y0',Y_out((i+1):(i+j)));
APE(i,j) = abs(gasforecast(end)-Y_out(end))/Y_out(end);