I'm using the autocorrelation command ac and the partial autocorrelation command pac. I'm running them on over 1,000 different time series with length T=12. May I ask a couple of questions?

The commands are slow because they generate a plot, which I don't want to see. Is there a way to save time by suppressing the plot? It's no big deal if you have only one time series, but if you have over 1,000, it's a drag.

The pac command won't calculate the partial autocorrelation for lags beyond 4. Why not? Is this an arbitrary software limit, or is there some mathematical reason you can't calculate the lag-5 autocorrelation from a time series with T=12.

Many thanks.