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> In terms of RNG data, Mandelbrot argues that prices have a "memory"
> and I don't believe that most RNG synthetic series take this into account.
Yes, that is where I got up to in my thinking, except I was doing it at a more abstract level.
I looked up Random, on Wikipedia, and something in that article triggered my thinking .... at the Universal level (I argued to myself) 'memory' is a fundamental principle and it is shaping absolute randomness (chaos) .... a truly random event would not produce any patterns at all that could be modelled i.e. probability would not exist and no event would follow any other event in any predictable way..... absolute randomness only 'exists' before existence (over to Physics and Cosmologists!)
the existence of probability == approximate or conditioned absolute randomness;
I couldn't decide if the mathematicians called it PseudoRandomness because the maths algorithms only approximated what they were trying to do OR if they were smart enough back then to realize that their randomness was only pseudo absolute randomness.
--- In amibroker@xxxxxxxxxxxxxxx, i cs <ics4mer@xxx> wrote:
>
> Hi,
>
> Mandelbot is a light read! Purposely written as such.
>
> There is already some M. inspired code in the AB libraries/user base,
> in particular what mandelbrot calls "H", and what others call the
> "Hurst Exponent". I haven't seen any code for synthetic price series
> though.
>
> In terms of RNG data, Mandelbrot argues that prices have a "memory"
> and I don't believe that most RNG synthetic series take this into account.
>
> Is randomness real? I don't think so. I think it's just stuff that we don't
> understand the flow of.
>
> Z
>
>
>
>
> ________________________________
> From: brian_z111 <brian_z111@xxx>
> To: amibroker@xxxxxxxxxxxxxxx
> Sent: Thursday, 18 June, 2009 4:25:47 PM
> Subject: [amibroker] Re: Benchmarking
>
>
>
>
>
> Very interesting topic.
>
> Mandelbrot is on my short list of fun reading.... obviously at some point I might have a look at the real code used by others to produce random data etc, including Mandelbrot's, and bring it into AB if it has not already been done (at the moment it is more of a trading hobby than a pursuit of applications) ... Howard is busy on his third book (advanced stuff) and other things so he might publish something interesting to stimulate us further on this subject ... perhaps some tools will appear (I am always confident that the AB community can surpass what is already out there, at least for non-academics) .
>
> I also got fascinated by the idea of absolute randomness and started to question if it really exists or is it just a useful model?
>
> --- In amibroker@xxxxxxxxx ps.com, i cs <ics4mer@ > wrote:
> >
> > Hi Brian,
> >
> > Interesting topic.
> >
> > Mandelbrot (seen one fractal, seen em all) has some excellent discussion
> > on synthetic data in his book "The (Mis)Behaviour of markets". He uses
> > a multifractal approach to producing simulated markets. The price
> > behaviour produced by his approach looks identical to real price data and
> > is not "psuedo random" in the ordinary sense.
> >
> > I think you'd like the book, it's very approachable, and all the maths
> > is hidden away in the back.
> >
> > Z
> >
> >
> >
> >
> > ____________ _________ _________ __
> > From: brian_z111 <brian_z111@ ...>
> > To: amibroker@xxxxxxxxx ps.com
> > Sent: Thursday, 18 June, 2009 3:46:20 PM
> > Subject: [amibroker] Re: Benchmarking
> >
> >
> >
> >
> >
> > Fixup
> >
> > /*P_RandomPriceSeri es*/
> >
> > //Use as a Scan to create PseudoRandomPriceSe ries
> > //Select Current symbol and All quotations in AA, select basetimeframe in AA Settings
> > //It will also create the series if used as an indicator (add the appropriate flag to ATC)
> > // but this is NOT recommended as it will recalculate them on every refresh.
> > //Indicator mode is good for viewing recalculated curves (click in whitespace)
> > //Do not have the indicator code uncommented while running the scan
> > //CommentOut the Scan code before using the indicator code.
> >
> > N = 100;//manually input desired Number - used in Scan AND Indicator mode
> >
> > ///SCAN///// ///////// ///////// ///////// ///////// ///////// ///////// ////////
> >
> > Buy=Sell=0;
> >
> > for( i = 1; i < N; i++ )
> >
> > {
> >
> > VarSet( "D"+i, 100 * exp( Cum(log(1 + (Random() - 0.5)/100)) ) );
> > AddToComposite( VarGet( "D"+i ),"~Random" + i,"X",1|2|128) ;
> > //Plot( VarGet( "D"+i ), "D"+i, 1,1 );
> > //PlotForeign( "~Random" + i,"Random" + 1,1,1);
> > }
> >
> > /*
> > ////PLOT//// ///////// ///////// ///////// ///////// ///////// ////
> >
> > //use the same period setting as for the Scan
> >
> > for( i = 1; i < N; i++ )
> >
> > {
> >
> > PlotForeign( "~Random" + i,"Random" + i,1,1);
> >
> > }
> >
> > */
> >
> > ////OPTIMIZE/ ///////// ///////// ///////// ///////// ///////// ///////// ////
> >
> > //use the filter to run on Group253 OR add ~Random + i PseudoTickers to a Watchlist and define by AA filter
> >
> > //fast = Optimize( "MA Fast", 1, 1, 10, 1 );
> > //slow = Optimize("MA Slow", 4, 4, 20, 1 );
> >
> > //PositionSize = -100/P;
> > //Buy = Cross(MA(C,fast) ,MA(C,slow) );
> > //Sell = Cross(MA(C,slow) ,MA(C,fast) );
> >
> > //Short = Sell;
> > //Cover = Buy;
> >
> > --- In amibroker@xxxxxxxxx ps.com, "brian_z111" <brian_z111@ ...> wrote:
> > >
> > > Following recent discussions on benchmarking and using rule based systems to engineer returns to meet 'clients' profiles i.e.Samantha' s MA(C,10) example, I did some follow up R&D with the intent of expanding the examination a little further via a zboard post.
> > >
> > > I may, or may not, get around to that so in the meantime I decided I would share a couple of things while they are still topical.
> > >
> > > I made up some quick and dirty randomly generated eq curves so that I could optimise MA(C,10) on them (out of curiosity).
> > >
> > > Also, out of curiosity, I decided to see how the example signal/filter code that I made up, as the study piece for Yofas topic on benchmarking, would actually perform.
> > >
> > > Buy = Ref(ROC(MA(C, 1),1),-1) < 0 AND ROC(MA(C,1), 1) > 0 AND ROC(MA(C,10) ,1) > 0;
> > > Sell = Cross(MA(C,10) ,C);//no thought went into this exit and I haven't tried any optimization of the entry or the exit
> > >
> > > By chance I noticed that it outperformed on one or two of the constituents of the ^DJI (Yahoo data ... 2005 to 2009) and to the naked eye the constituents all seem to be correlated to a fair extent over that time range.
> > >
> > > Also, to the naked eye, it outperforms on randomly generated stock prices around 50% of the time and the outperformnce doesn't appear to be correlated to the underlying(I haven't attempted to find an explanation for this).
> > >
> > > Here is the code I used to make up some randomly generated 'stocks'.
> > >
> > > As we would expect it produces, say, 100 price series with a concatenated mean of around zero (W/L = 1 and PayoffRatio == 1) etc.
> > > When plotted at the same time ... individual price series are dispersed around the mean in a 'probability cone' ... in this case it is a relatively tight cone because the method doesn't introduce a lot of volatility to the series.
> > >
> > > /*P_RandomEquity* /
> > >
> > > //Use as a Scan to create PseudoRandom Equity curves
> > > //Current symbol, All quotations in AA, select basetimeframe in AA Settings
> > > //It will also create the curves if used as an indicator (add the appropriate flag to ATC)
> > > // but this is NOT recommended as it will recalculate them on every refresh.
> > > //Indicator mode is good for viewing recalculated curves (click in whitespace)
> > > //CommentOut the Scan code before using the indicator code.
> > > //Don't use a very large N or it will freeze up indicator scrolling etc
> > >
> > > n = 100;//manually input desired number - used in Scan AND Indicator mode
> > >
> > > ///SCAN///// ///////// ///////// ///////// ///////// ///////// ///////// ////////
> > >
> > >
> > > Buy=Sell=0;
> > >
> > > for( i = 1; i < n; i++ )
> > >
> > > {
> > >
> > > VarSet( "D"+i, 100 * exp( Cum(log(1 + (Random() - 0.5)/100)) ) );
> > > AddToComposite( VarGet( "D"+i ),"~Random" + i,"X",1|2|128) ;
> > > //Plot( VarGet( "D"+i ), "D"+i, 1,1 );
> > > //PlotForeign( "~Random" + i,"Random" + 1,1,1);
> > > }
> > >
> > > /*
> > > ////PLOT//// ///////// ///////// ///////// ///////// ///////// ////
> > >
> > > //use the same number setting as for the Scan
> > >
> > >
> > > for( i = 1; i < n; i++ )
> > >
> > > {
> > >
> > > PlotForeign( "~Random" + i,"Random" + i,1,1);
> > >
> > > }
> > >
> > >
> > > ////OPTIMIZE/ ///////// ///////// ///////// ///////// ///////// ///////// ////
> > >
> > > //use the filter to run on Group253 OR add ~Random + i PseudoTickers to a Watchlist and define by AA filter
> > >
> > >
> > > //fast = Optimize( "MA Fast", 1, 1, 10, 1 );
> > > //slow = Optimize("MA Slow", 4, 4, 20, 1 );
> > >
> > > //PositionSize = -100/P;
> > > //Buy = Cross(MA(C,fast) ,MA(C,slow) );
> > > //Sell = Cross(MA(C,slow) ,MA(C,fast) );
> > >
> > > //Short = Sell;
> > > //Cover = Buy;
> > >
> > > I also stumbled on this, which seems to have some relevance:
> > >
> > > http://www.scribd. com/doc/6737301/ Trading-eBookCan -Technical- Analysis- Still-Beat- Random-Systems
> > >
> > >
> > > It contains a link to a site that has a free download of some RNG produced datasets.
> > >
> > > There hasn't been much discussion on using synthetic data in the forum ... Patrick recommended it for testing? OR benchmarking? ... Fred is against using it ("If we knew enough about the characteristics of the data, in the first place, to be able to create synthetic data then we would know enough to design trading systems to exploit the data's profile anyway", OR something like that).
> > >
> > > I was titillated enough by my first excursion into benchmarking with synthetic data to bring me back for some more.
> > >
> >
> >
> >
> >
> >
> > Access Yahoo!7 Mail on your mobile. Anytime. Anywhere.
> > Show me how: http://au.mobile. yahoo.com/ mail
> >
>
>
>
>
>
> Access Yahoo!7 Mail on your mobile. Anytime. Anywhere.
> Show me how: http://au.mobile.yahoo.com/mail
>
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