Hello, You can use SetBarsRequired to override any internal estimate as described in the KB: http://www.amibroker.com/kb/2008/07/03/quickafl/
Note however that QuickAFL is only enabled in Automatic Analysis starting from version 5.14. Any versions prior to that only use QuickAFL for indicators. Best regards, Tomasz Janeczko amibroker.com ----- Original Message ----- From: "Ronald Davis" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Friday, August 22, 2008 12:13 AM Subject: Re: [amibroker] Re: Size of Database... > Thanks for the Info Steve. > > Is the below example how I would like to be able to use SETBARSREQUIRED. > Also, will it work in my version > > 5.00, which is the last upgrade that I am entitled to. > > I will eagerly pay TJ more money to upgrade if I will REALLY be able to use > SETBARSREQUIRED in a simple > > way to limit the LOOKBACK period to 101 days. Thanks Ron D. > ------------------------------------------------------------------------------------------------- > pk IS THE>pink line, AND yl IS THE>>yellow line , AND mn > IS>>MIN(bk,MIN(yl,gn)); > ------------------------------------------------------------------------------------------------- > sq1=pk==mx AND yl >bk AND bk>mn AND wh==mn; > > rq1=Sum(bkxmn,3) AND Sum(ylxmn,3) AND > ValueWhen(rddip,Sum(rd<35,2),1); > > Buy1=sq1 and rq1 and SetBarsRequired(101); > ---------------------------------------------------------------------- > ----- Original Message ----- > From: "Steve Dugas" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Thursday, August 21, 2008 4:14 PM > Subject: Re: [amibroker] Re: Size of Database... > > >> Hi Ron - I believe the user does have final control over how far AB looks >> back. If you place SetBarsRequired at the *end* of your code I think it >> will >> override what AB has previously calculated. It is discussed in the recent >> ReadMe file. >> >> Steve >> >> ----- Original Message ----- >> From: "Ronald Davis" <[EMAIL PROTECTED]> >> To: <[email protected]> >> Sent: Thursday, August 21, 2008 4:24 PM >> Subject: Re: [amibroker] Re: Size of Database... >> >> >>> sidhartha70>>>So as a DB management strategy, it's best to perhaps have a >>> large DB >>> for backtesting purposes only... and a much smaller DB for live >>> trading, charting, symbol swithcing etc..etc...?? >>> ------------------------------------------------------------------------------------------ >>> I think I remember that SET BARS REQUIRED will "NOT" stop Amibroker from >>> looking back through the last 30 years even though I am looking at only >>> the >>> last day. >>> >>> I would sure like a feature in Amibroker that would make SET BARS >>> REQUIRED >>> lookback only 101 days when the indicator looks back only 100 days. >>> >>> My backtesting days officially ended a few days ago. >>> >>> My backtesting consisted of viewing my indicator buy signals against 30 >>> years of historical data. >>> >>> Even though I no longer backtest, I would still like to have a 30 year >>> database, and here is why. >>> >>> Those symbols that are less volatile tend to have a decent amount of >>> pattern >>> similarity in my indicators as they enter into a NEW uptrend, after >>> having >>> been on a long term DOWNTREND. >>> >>> If I keep my 30 year database, then when I get a BUY signal, I can look >>> back >>> at the beginning of the previous new uptrends that occurred over the last >>> 30 >>> years. This lookback helps me decide how good the signal is. Ron D >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> >>> ----- Original Message ----- >>> From: "sidhartha70" <[EMAIL PROTECTED]> >>> To: <[email protected]> >>> Sent: Thursday, August 21, 2008 8:59 AM >>> Subject: [amibroker] Re: Size of Database... >>> >>> >>>> Thanks TJ. >>>> >>>> So as a DB management strategy, it's best to perhaps have a large DB >>>> for backtesting purposes only... and a much smaller DB for live >>>> trading, charting, symbol swithcing etc..etc...?? >>>> >>>> Thanks >>>> >>>> --- In [email protected], "Tomasz Janeczko" <[EMAIL PROTECTED]> >>>> wrote: >>>>> >>>>> Using 10x more data per symbol will give you slow down in all areas. >>>>> 2 million bars is 64 MB per symbol of quote data and 8 MB per single >>>> AFL array >>>>> (if quickafl is not used). As formulas depending on complexity can >>>> use hundreds of arrays >>>>> this means approaching gigabytes of RAM. >>>>> Handling that much of data is not "easy". Remember than RAM bandwidth >>>>> is limited to few GB per second. Therefore just accessing that amount >>>>> of data is question of seconds, not counting the calculations. >>>>> >>>>> Best regards, >>>>> Tomasz Janeczko >>>>> amibroker.com >>>>> ----- Original Message ----- >>>>> From: "sidhartha70" <[EMAIL PROTECTED]> >>>>> To: <[email protected]> >>>>> Sent: Thursday, August 21, 2008 2:48 PM >>>>> Subject: [amibroker] Re: Size of Database... >>>>> >>>>> >>>>> > Anyone...? >>>>> > >>>>> > Many Thanks >>>>> > >>>>> > --- In [email protected], "sidhartha70" <sidhartha70@> wrote: >>>>> >> >>>>> >> This may have been answered before, but... >>>>> >> >>>>> >> I set up two DB's in AB... both IQ Feed tick DB's. >>>>> >> >>>>> >> 1. Is 200,000 bars per symbol. >>>>> >> 2. The second is 2,000,000 per symbol. >>>>> >> >>>>> >> Practially, operationally, where will AB be slower in the use of the >>>>> >> second DB...?? In charting? Backtesting (obviosuly)? In symbol >>>>> >> switching etc...? >>>>> >> >>>>> >> I'm just trying to work out how motivated I should be to have small >>>>> >> DB's... >>>>> >> >>>>> >> Thanks >>>>> >> >>>>> > >>>>> > >>>>> > >>>>> > ------------------------------------ >>>>> > >>>>> > Please note that this group is for discussion between users only. >>>>> > >>>>> > To get support from AmiBroker please send an e-mail directly to >>>>> > SUPPORT {at} amibroker.com >>>>> > >>>>> > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>>>> > http://www.amibroker.com/devlog/ >>>>> > >>>>> > For other support material please check also: >>>>> > http://www.amibroker.com/support.html >>>>> > Yahoo! Groups Links >>>>> > >>>>> > >>>>> > >>>>> >>>> >>>> >>>> >>>> ------------------------------------ >>>> >>>> Please note that this group is for discussion between users only. >>>> >>>> To get support from AmiBroker please send an e-mail directly to >>>> SUPPORT {at} amibroker.com >>>> >>>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>>> http://www.amibroker.com/devlog/ >>>> >>>> For other support material please check also: >>>> http://www.amibroker.com/support.html >>>> Yahoo! Groups Links >>>> >>>> >>>> >>> >>> >>> >>> ------------------------------------ >>> >>> Please note that this group is for discussion between users only. >>> >>> To get support from AmiBroker please send an e-mail directly to >>> SUPPORT {at} amibroker.com >>> >>> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >>> http://www.amibroker.com/devlog/ >>> >>> For other support material please check also: >>> http://www.amibroker.com/support.html >>> Yahoo! Groups Links >>> >>> >>> >>> >> >> >> >> ------------------------------------ >> >> Please note that this group is for discussion between users only. >> >> To get support from AmiBroker please send an e-mail directly to >> SUPPORT {at} amibroker.com >> >> For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: >> http://www.amibroker.com/devlog/ >> >> For other support material please check also: >> http://www.amibroker.com/support.html >> Yahoo! Groups Links >> >> >> > > > > ------------------------------------ > > Please note that this group is for discussion between users only. > > To get support from AmiBroker please send an e-mail directly to > SUPPORT {at} amibroker.com > > For NEW RELEASE ANNOUNCEMENTS and other news always check DEVLOG: > http://www.amibroker.com/devlog/ > > For other support material please check also: > http://www.amibroker.com/support.html > Yahoo! Groups Links > > >
