Hi,

I am currently doing some research on optimization criteria and i´ve got stuck trying to apply LinearRegSlope*R2 to optimize parameters.

This code gives me an error regarding i need more lookback period:



I´ve also tried with Day instead of Bar-StarBar, and even putting directly a number lower than lookback for the period gets a crush.

¿How could i achieve this?

The alternative is using (WinTotal-LossTotal)*R2, but this is not what i really want.

Day is correct for getting the regression slope of the equity curve, but be aware: ResultsDaily is in chronological order, not reversed like a series. So use the negative slope. Lookback must be set to the number of days in the simulation, or above.

Ok, I understand.

The problem with increasing lookback is i run out of enough bars... So i can´t properly test this criteria.

I thought i wouldn´t need lookback for this, as in other platforms is not necessary, just take the whole equity and go.

Then set lookback to 0 when you don't need it. If Lookback is not 0, Zorro assumes that you need it for something.

I see your point, but at least in this case if i set lookback to 0, then no optimization is performed (everything returns 0) and the system is useless.

The only solution as it seems to be is just having at least double historic data than simulation period, if not, i can´t use this function.

So, i am afraid i´ll forget about this unless someone has an alternative solution.

Thanks.

Why so complicated? If you need lookback in the test, but not in the objective function, then set lookback in the run function to the value you need, and to 0 in the objective function.

The main purpose of variables like lookback is preventing errors. You normally adapt them to your script, not your script to the variables.

Sorry jcl but it still doesn´t work...

I´ve done as you state, and with other criteria goes fine but when i apply LinearRegSlope whether with Day, Bar-StarBar or a fixed number it crushes.

Quite strange indeed...

Thanks.

Ok. I cannot tell why "it crushes" because I have not yet used an indicator on something else than a data series. But here is how to look into such a problem.

First, check if ResultsDaily is really nonzero in the objective function. I believe it is, but otherwise the problem is clear.

Next, call LinearRegSlope with something simple, like an array { 1, 2, 3 } of length 3, and check if it still "crushes". If so, then LinearRegSlope only works with a real data series for some reason, and you need the more common polyFit function. When you're at this point, post again and I'll help.

Hi jcl.

ResultsDaily is nonzero and it´s reversed as you stated.

LinearRegSlope(ResultsDaily,Day) with LookBack = 0 doesn't seem to work properly. It always returns 1, maybe there is an issue with the reversed order of the series.

polyfit(0,ResultsDaily,Day,1,1) letting LookBack with its original value produces different results in training, but in test mode the system results aren't profitable when other criteria do.

I think i need to reverse the series or apply the slope over the differencies, need some help.

Thanks.

I've checked now, but all the indicators definitely work with LookBack=0. Lookback=0 just switches off the error message.

So your problem has a different reason that is unrelated to LookBack. Without seeing your code this is of course hard to tell. It's not reversing the series - this just changes the sign of the slope.

Some lines of code for testing LinearRegSlope wit no LookBack - maybe it helps: