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Molson Export please ;)
Mike
--- In amibroker@xxxxxxxxxxxxxxx, Nick Willemse <nick.willemse@xxx> wrote:
>
> Thanks Mike! I owe you a beer!
>
> That was the problem trying to send that array with only numTrades
> values across to the backtester section. After sending the full array
> of MaxStopLoss points, then using your entryBar code to get the entry
> bar, I was able to extract the risk per trade properly.
>
> Thanks for the help!!
>
> Nick
>
>
> On Jul 16, 2009, at 11:25 AM, Nick Willemse wrote:
>
> > Thanks Mike,
> >
> > I understand. I saw your code to get the entryBar, so that will
> > help. I'm going to give it a try...
> >
> > nick
> >
> > On Jul 16, 2009, at 10:54 AM, Mike wrote:
> >
> >> Nick,
> >>
> >> I have not studied your code in depth, nor tested it out yet. But,
> >> assuming everything else is correct, two things stand out.
> >>
> >> 1. In your initialization loop for MSL, you should really be
> >> iterating from bar=0 to bar<BarCount, not bar=1. As it stands, if
> >> you get a signal on bar=0, you will not store the risk for it. When
> >> iterating through your trades later, all trades would be using the
> >> wrong risk, offset by one position in the array.
> >>
> >> That being said, there's no need for this loop at all. I believe
> >> that the entire loop can be replaced with the following:
> >>
> >> MSL = IFF(Buy OR Short, Risk, 0);
> >>
> >> 2. It appears that you are trying to create MSL as a non sparse
> >> array (i.e. values all at consecutive indices) rather than a sparse
> >> array (i.e. values of interest whose indices may be widely spaced
> >> apart). This is likely the root of your problem.
> >>
> >> For example, you are populating the array per signal, but then
> >> querying the values per trade. Due to portfolio restrictions, not
> >> all signals will necessarily have become trades (e.g. lack of
> >> funds, max open positions, etc). As soon as any signal did not
> >> result in a trade, your algorithm falls apart and you will be
> >> referencing the wrong risk index for all subsequent trades.
> >>
> >> Using the sparse array assignment for MSL given above, and the bar
> >> indexing of the trade as suggested in my earlier notes, you would
> >> not suffer this problem.
> >>
> >> You might also run into alignment problems if the array size of
> >> ~~~Equity is different than ~MSL. Again, using bar index of trade
> >> would avoid that.
> >>
> >> Mike
> >>
> >> --- In amibroker@xxxxxxxxxxxxxxx, Nick Willemse <nick.willemse@>
> >> wrote:
> >> >
> >> > Hi,
> >> >
> >> > Attached is the afl. This runs on EC 5min database. If you want me
> >> > to upload this db to the files section, i'll be happy to do it.
> >> I've
> >> > tried everything. For some reason I just cannot pass the risk per
> >> > trade to the backtester just to output the values and calc r-
> >> > multiples. I can't believe how difficult and cumbersome this
> >> process
> >> > is. The values are in the ~MSL before the backtester.
> >> >
> >> > Mike, if will be much harder to recalc the ATR array in the
> >> bactester
> >> > and trying to figure out which bar the trade happened and take that
> >> > value from the array as the original risk. That's why i'm trying to
> >> > pass it. Also, if the trade object had a method getEntryBarNum it
> >> > would have been easier.
> >> >
> >> > Any help appreciated!
> >> > Nick
> >> >
> >> >
> >> >
> >> > On Jul 15, 2009, at 9:04 PM, Mike wrote:
> >> >
> >> > > Nick,
> >> > >
> >> > > Since ATR uses OHLC I'm assuming that it will use the OHLC of the
> >> > > foreign symbol once bracketed by SetForeign/RestorePriceArrays.
> >> > >
> >> > > The point that I was trying to stress was that once you've called
> >> > > SetForeign, you can do all kinds of array manipulations on that
> >> > > symbol, then reference the value you want for the bar in
> >> question.
> >> > >
> >> > > In other words, instead of trying to reference your external
> >> array
> >> > > FROM the backtester code, calculate the array IN the backtester
> >> code.
> >> > >
> >> > > Look again at the earlier post and try using ATR between
> >> SetForeign/
> >> > > RestorePriceArrrays.
> >> > >
> >> > > That being said, when looking again at your original code example
> >> > > and taking a cue from Bruce's reply; try using "X" in both the
> >> > > AddToComposite and Foreign, and use atcFlagEnableInPortfolio
> >> instead
> >> > > of atcFlagEnableInBacktest.
> >> > >
> >> > > Mike
> >> > >
> >> > > --- In amibroker@xxxxxxxxxxxxxxx, Nick Willemse <nick.willemse@>
> >> > > wrote:
> >> > > >
> >> > > > Thanks Mike,
> >> > > >
> >> > > > Yea, van tharp's stuff makes a lot of sense to me :)
> >> > > >
> >> > > > The example you've posted still uses only price data, which is
> >> > > kind of
> >> > > > straight forward referring back to price. I am using that
> >> value of
> >> > > > the ATR of price. The problem is trying to make this
> >> value(array)
> >> > > > available in the backtester part of the code.
> >> > > >
> >> > > >
> >> > > > Nick
> >> > > >
> >> > > > On Jul 15, 2009, at 1:32 PM, Mike wrote:
> >> > > >
> >> > > > >
> >> > > > >
> >> > > > > This is a popular topic lately. Van Tharp must be doing
> >> well with
> >> > > > > his new book ;)
> >> > > > >
> >> > > > > See my earlier post on the subject for how to calculate the
> >> risk
> >> > > > > anyway you see fit. Note that the expectancy shown in that
> >> post
> >> > > was
> >> > > > > the formula provided by the original poster, it is not the
> >> formula
> >> > > > > used by Van Tharp, so refer to the methodology, but not the
> >> > > formula:
> >> > > > >
> >> > > > > http://finance.groups.yahoo.com/group/amibroker/message/
> >> 139969
> >> > > > >
> >> > > > > Mike
> >> > > > >
> >> > > > > --- In amibroker@xxxxxxxxxxxxxxx, Nick Willemse
> >> <nick.willemse@>
> >> > > > > wrote:
> >> > > > > >
> >> > > > > > Hi Everyone,
> >> > > > > >
> >> > > > > > I'm trying to add Risk and R-Multiples to the TradeList.
> >> I've
> >> > > looked
> >> > > > > > at the example using MaxLossPercent to add r-multiples and
> >> > > that is
> >> > > > > > pretty straight forward. However, my risk per trade is
> >> based
> >> > > on some
> >> > > > > > multiple of the ATR. So I put the risk points per trade
> >> in an
> >> > > array,
> >> > > > > > then I tried using the addtocomposite and Foreign
> >> functions to
> >> > > get
> >> > > > > > this array to the backtester section, but it seems that all
> >> > > the data
> >> > > > > > is zero when it gets to the backtester. Is there any
> >> other way
> >> > > to
> >> > > > > > make this array holding the risks per trade available to
> >> the
> >> > > > > > backtester to output this for each trade?
> >> > > > > >
> >> > > > > > Here's some of the code:-
> >> > > > > >
> >> > > > > >
> >> > > > > > Risk = 2.5 * ATR(14);
> >> > > > > > i = 0;
> >> > > > > > MSL = 0;
> >> > > > > > for( bar=1; bar < BarCount; bar++)
> >> > > > > > {
> >> > > > > > if (Buy[bar] == 1 OR Short[bar] == 1)
> >> > > > > > {
> >> > > > > > MSL[i] = Risk[bar];
> >> > > > > > // _TRACE("MSL = " + MSL[i]); //this outputs correct
> >> values
> >> > > > > > i++;
> >> > > > > > }
> >> > > > > > }
> >> > > > > > AddToComposite( MSL,"~MSL","V", atcFlagDeleteValues |
> >> > > > > > atcFlagEnableInBacktest); // if i plot this it looks fine
> >> > > > > >
> >> > > > > > ...
> >> > > > > >
> >> > > > > > if(AAAction == actionPortfolio)
> >> > > > > > {
> >> > > > > > MSL = Foreign("~MSL", "X",0);
> >> > > > > > _TRACE("MSL=" + MSL[0]); // this output 0 for every index
> >> in the
> >> > > > > > array
> >> > > > > > ...
> >> > > > > >
> >> > > > > > }
> >> > > > > >
> >> > > > > >
> >> > > > > >
> >> > > > > > Nick
> >> > > > > >
> >> > > > >
> >> > > > >
> >> > > > >
> >> > > >
> >> > >
> >> > >
> >> > >
> >> >
> >>
> >>
> >>
> >
>
------------------------------------
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