The simple answer .
An intelligent optimizer regardless of which one will greatly reduce optimization time as unlike an exhaustive search, run time is typically not related to the number of variable value combinations. As a simple example visualize a system made up of two indicators i.e. a Stochastic and a MACD each of which has 3 parameters and assume for the moment that each parameter or variable has a potential range of 1 - 100. That's 100 ^ 6 = 10 ^ 12 combinations. If your "engine" is capable of checking 100 combinations per second then run time = 1 * 10 ^ 10 seconds.or 300+ years. Run time for an intelligent optimizer to solve the same problem would be measured in seconds or minutes and this won't vary much whether there are 6 parameters or 600. _____ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of sidhartha70 Sent: Friday, September 19, 2008 7:48 PM To: [email protected] Subject: [amibroker] Re: Confusing Behaviour...!!! Tj thanks. But I just want to get this 100% clear so I don't have to come back to this again. On exactly the same chart... same settings, same zoom etc... One line of code requires 5,000 previous bars within a function structure, and outside of a function structure it requires 500. Why? It makes no difference if I move around the chart, or zoom the chart etc. The number of pervious bars required doesn't seem dynamic. It's very much fixed. In the case of the following lines, H1=SelectedValue(TimeFrameGetPrice( "H", inDaily, -1 )); L1=SelectedValue(TimeFrameGetPrice( "L", inDaily, -1 )); C1=SelectedValue(TimeFrameGetPrice( "C", inDaily, -1 )); They require 5,000 bars each. Again, why? Sorry to be thick here, and I'm sure it's blindingly obvious to you... But I don't see how BarCount has anything to do with these two examples...?? Thanks Again for taking the time. --- In [EMAIL PROTECTED] <mailto:amibroker%40yahoogroups.com> ps.com, "Tomasz Janeczko" <[EMAIL PROTECTED]> wrote: > > BarCount is DYNAMIC, it may change with every execution. > You should not think about it as a constant. > It can change with zoom factor, tooltip display (uses less), > interpretation, selected bar, etc, etc. > > Also first execution after applying indicator always uses > all bars, only subsequent runs use less. > > Best regards, > Tomasz Janeczko > amibroker.com > ----- Original Message ----- > From: "sidhartha70" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED] <mailto:amibroker%40yahoogroups.com> ps.com> > Sent: Saturday, September 20, 2008 1:15 AM > Subject: [amibroker] Re: Confusing Behaviour...!!! > > > > Thanks TJ. I do know about Quick AFL and I have read that document > > throughly before. > > > > But I can't see how it applies in this case with these specific > > examples. And I definately can't see the difference between one being > > inside a function or not. > > > > Can you explain? > > > > TIA > > > > --- In [EMAIL PROTECTED] <mailto:amibroker%40yahoogroups.com> ps.com, "Tomasz Janeczko" <groups@> wrote: > >> > >> Please read this: > >> > >> http://www.amibroke <http://www.amibroker.com/kb/2008/07/03/quickafl/> r.com/kb/2008/07/03/quickafl/ > >> > >> Best regards, > >> Tomasz Janeczko > >> amibroker.com > >> ----- Original Message ----- > >> From: "sidhartha70" <sidhartha70@> > >> To: <[EMAIL PROTECTED] <mailto:amibroker%40yahoogroups.com> ps.com> > >> Sent: Saturday, September 20, 2008 12:50 AM > >> Subject: [amibroker] Confusing Behaviour...!!! > >> > >> > >> > Hi, > >> > > >> > I'm trying to get some code to run as fast as possible. As such I've > >> > been studying the 'Display Chart Timing' option under > > preferences>misc. > >> > > >> > I've noticed some behaviour that I can't explain. I hope others may be > >> > able to. > >> > > >> > Firstly I notice that when my chart requires 10,000+ bars I start to > >> > notice latency in AmiBroker, despite running a very fast PC. I assume > >> > that is normal at that number of bars...? > >> > > >> > So here's the problem... > >> > > >> > Under normal circumstances my code requires 297 previous bars. > >> > > >> > However, If I add the following lines, the number of previous bars > >> > required increases by 5,000 for each instance. So after these three > >> > lines of code I am now needing 15,297 pervious bars. > >> > > >> > H1=SelectedValue(TimeFrameGetPrice( "H", inDaily, -1 )); > >> > L1=SelectedValue(TimeFrameGetPrice( "L", inDaily, -1 )); > >> > C1=SelectedValue(TimeFrameGetPrice( "C", inDaily, -1 )); > >> > > >> > Even stranger, when I add the following line of code into the main > >> > body of code, > >> > > >> > test=((BarCount - 1) - LastValue(TroughBars(L, 0.05,10))); > >> > > >> > It adds 500 bars to my previous bars required (total new 797). > >> > > >> > However if I call a function and simply return the following, > >> > > >> > return ((BarCount - 1) - LastValue(TroughBars(L, 0.05,10))); > >> > > >> > It now requires 5,000 previous bars instead of the 500 outside of the > >> > function (total now 5,297). > >> > > >> > Can anyone explain this behaviour...? > >> > > >> > Many 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.amibroke <http://www.amibroker.com/devlog/> r.com/devlog/ > >> > > >> > For other support material please check also: > >> > http://www.amibroke <http://www.amibroker.com/support.html> r.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.amibroke <http://www.amibroker.com/devlog/> r.com/devlog/ > > > > For other support material please check also: > > http://www.amibroke <http://www.amibroker.com/support.html> r.com/support.html > > Yahoo! Groups Links > > > > > > > _____ I am using the free version of SPAMfighter for home users. SPAMfighter has removed 549 spam emails to date. Paying users do not have this message in their emails. Try SPAMfighter <http://www.spamfighter.com/len> for free now!
