--- In
amibroker@xxxxxxxxxxxxxxx, "Howard B" <howardbandy@xxx> wrote:
>
> Hi Louis, and all --
>
> I know David Aronson, respect him, and like and recommend his book.
>
> My view is that the in-sample period should be as short as
practical. My
> thought is that: the system we are testing / trading is trying to
recognize
> the signal from among the noise; and the signal patterns are
changing over
> time. So the length of the in-sample period is a tradeoff -- short
to be
> able to change as the characteristics of the underlying market
change, but
> not so short that the system is over-fit to the noise rather than
learns the
> signal.
>
> You can test this in AmiBroker. Have your system ready to buy and
sell. In
> the Automatic Analysis window, use Settings and set up the Walk
Forward
> parameters. Try an in-sample period of 10 years, an out-of-sample
period of
> 6 months or 1 year. Run Optimize > Walk Forward and look at the in-
sample
> and out-of-sample equity curves. Shorten the length of the in-
sample period
> to 9, then 8, then 7, ... then 1 year, keeping the out-of-sample
period
> unchanged. Depending on your system and the market it is trading,
you may
> find that there is a sweet spot in the length of the in-sample
data. If so,
> that is the amount of data that allows your system to recognize the
signal
> without being overwhelmed by the noise.
>
> Thanks,
> Howard
>
>