Hello Mike, WOW - I never expected to get a whole piece of code!
I now need to digest what you wrote, since coding doesn´t come that easy to me! Thanks loads! Markus ----- Original Message ----- From: Mike To: [email protected] Sent: Monday, November 02, 2009 12:34 AM Subject: [amibroker] Re: Trade lists vs. signal list in custom backtester Markus, Run the script below on a watchlist of just a handful of symbols (e.g. 4) over a short duration (e.g. month of October), then study the TRACE output. The TRACE output will show the complete lifecycle of signal to position to closed trade. To see the TRACE output, make sure that your AmiBroker Log window is opened to the Trace tab. You may additionally need to right click in the body area of the Trace tab page and make sure that "Trace Output -> Internal" is selected. To answer your specific questions: 1. I'm not entirely sure what you are asking. But, I believe that the answer is yes, as shown in the TRACE output. At each bar, signals are either accepted or rejected for that bar. Accepted signals will cause a new trade to be added to the position list (entry signal) or an existing trade to be moved from the open position list to the closed list (exit signal). This process is repeated for each bar in sequence. 2. Yes. This can be seen in the TRACE output. The open and closed lists include a running tally up to the current bar index. 3. No. The call to ProcessTradeSignals is the call responsible for shuttling signals to open positions and open positions to closed trades (on a bar by bar basis), not PostProcess.. PostProcess is a one time call at the very end to clear out memory and move the remaining open trades to the closed list. Actually, AmiBroker does not seem to expose the final transfer of open trades to closed except as reflected in the report. I was surprised to see that the closed trade list does not get affected after PostProcess (using standard edition 5.26.5), contrary to the documentation which says "When backtest is completed (after PostProcess call) AmiBroker closes out all open positions, so trade list includes all trades." You can send a follow up to support for that one. 4. No, do not use ListTrades. Depending on what you were trying to do, you could use UpdateStats, but I would advise staying away from that until you really knew what was going on. It's pretty rare that you would need that. 5. The last lines of the sample script show how to use LastValue and ValueWhen to get the bar of the trade based on the date. Mike SetTradeDelays(0, 0, 0, 0); SetPositionSize(2, spsPercentOfEquity); weekDay = DayOfWeek(); Buy = weekDay == 1; BuyPrice = Open; Sell = weekDay == 5; SellPrice = Close; SetCustombacktestProc(""); if (Status("action") == actionPortfolio) { bo = GetBacktesterObject(); bo.PreProcess(); for (bar = 0; bar < BarCount; bar++) { _TRACE("Bar " + bar); count = 0; for (trade = bo.GetFirstOpenPos(); trade; trade = bo.GetNextOpenPos()) { count++; } _TRACE(" There were " + count + " open positions at the start of the bar"); count = 0; for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade()) { count++; } _TRACE(" There were " + count + " closed trades at the start of the bar"); count = 0; count2 = 0; for (sig = bo.GetFirstSignal(bar); sig; sig = bo.GetNextSignal(bar)) { if (sig.IsEntry()) { count++; } else { count2++; } } _TRACE(" There were " + count + " entry signals found during the bar"); _TRACE(" There were " + count2 + " exit signals found during the bar"); bo.ProcessTradeSignals(bar); count = 0; for (trade = bo.GetFirstOpenPos(); trade; trade = bo.GetNextOpenPos()) { count++; } _TRACE(" There were " + count + " open positions after the bar"); count = 0; for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade()) { count++; } _TRACE(" There were " + count + " closed trades after the bar"); } count = 0; for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade()) { count++; } _TRACE("There were " + count + " closed trades before final processing"); bo.PostProcess(); count = 0; for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade()) { count++; } _TRACE("There were " + count + " closed trades after final processing (including closed open trades)"); indices = BarIndex(); dates = DateTime(); trade = bo.GetFirstTrade(); _TRACE("The entry bar of the first trade was " + LastValue(ValueWhen(trade.EntryDateTime == dates, indices))); _TRACE("The exit bar of the first trade was " + LastValue(ValueWhen(trade.ExitDateTime == dates, indices))); } --- In [email protected], "Markus Witzler" <funny...@...> wrote: > > Hi Mike, > > sorry for getting back so late. > > Your comments shed some light on my probs. > > If I may, a few more things need to be clarified: > > 1. In the CBL low.level loop below, will the signal loop be processed for one instance of "i", then the following trade loop (open and closed trades). Afterwords, i gets incremented by one and the whole starts again? > > 2. If so, did I understand you correctly that closed and open trade lists hold ALL closed (respectively open) trades that have been generated by signals (from signal list) up to the value "i" holds for any given moment? I.e. if "i" holds the value of "10" the trade lists (open or close) hold ALL trades up to that bar even though the bar number is now beign store but the date (entry and exit)? > > 3. The command "postprocess" in mid- and low-level turns signals into trades and thus moves them from one list to the other?! But then the postprocess comand should stand beetween signal and trade list, right. Otherwhise the shift would occur the NEXt time the loop is being processed?! > > 4. You wrote" If necessary, you can write code to monitor the lists on a bar by bar basis to track the trade activity" - could you givew me a short clue what to do? Would I have to used "list trades" and "updatestats" in each run of the loop after each trade? > > 5. You wrote "The bar index of the trade entry/exit is not stored as part of the trade object. But, the entry/exit dates are. Using that information you could calculate the bar index if you really needed it." I may be interested how to do this as well. A short hint would be fine. > > I don´t wnat to make it more complex than it is, but I sometimes just don´t understand the inner workings of CBT and thus can´t come up with the proper code. > > Sorry for my ignorance! > > Markus > > > > > ----- Original Message ----- > From: Mike > To: [email protected] > Sent: Thursday, October 29, 2009 12:36 AM > Subject: [amibroker] Re: Trade lists vs. signal list in custom backtester > > > Hi, > > Using the mid and low level backtester, trades get added/removed to/from the lists on a bar by bar basis at the point where the respective signals get processed (e.g. bo.ProcessTradeSignals(i) in mid level backtester). > > Once taken, open trades remain in the open list, possibly spanning multiple bar indices, until they are closed. When closed, the trades are moved to the closed list and will remain there for the duration of the backtest. > > A trade does not appear in any list until a signal is accepted by the backtester (e.g. the lists at bar 100 will not contain a trade that only gets opened at bar 110). Once taken, it will always be accessible in one of the lists from that point forward. If necessary, you can write code to monitor the lists on a bar by bar basis to track the trade activity. > > The bar index of the trade entry/exit is not stored as part of the trade object. But, the entry/exit dates are. Using that information you could calculate the bar index if you really needed it. > > Mike > > --- In [email protected], "Markus Witzler" funnybiz@ wrote: > > > > Hello, > > > > I have trouble understanding trade lists (open/closed) in custom backtester. > > > > As opposed to signal lists which carry an index variable and thus only process signals for a specific bar, trade lists haven´t. > > > > Consider the following code template in low-level CBT mode > > SetCustomBacktestProc(""); > > if (Status("action") == actionPortfolio) > > { > > bo = GetBacktesterObject(); // Get backtester object > > bo.PreProcess(); // Do pre-processing > > for (i = 0; i < BarCount; i++) // Loop through all bars > > { > > for (sig = bo.GetFirstSignal(i); sig; sig = bo.GetNextSignal(i)) > > { // Loop through all signals at this bar > > . . . . > > } // End of for loop over signals at this bar > > for (trade = bo.GetFirstTrade(); trade; trade = bo.GetNextTrade()) > > { > > . . . . > > } > > for (trade = bo.GetFirstOpenPos(); trade; trade = bo.GetNextOpenPos()) > > { > > . . . . > > } > > bo.HandleStops(i); // Handle programmed stops at this bar > > bo.UpdateStats(i, 1); // Update MAE/MFE stats for bar > > bo.UpdateStats(i, 2); // Update stats at bar's end > > } // End of for loop over bars > > bo.PostProcess(); // Do post-processing > > } > > I understand, that each run, signal list is being processed for a different value of "i". But how is trade list being used. Since there is no index variable "i", I can´t figure out if trade objects are being searched for a different value of "i" than in signal list, or if whole list of trades (for all bars) is being processed at each occurrence of "i" in the main loop. > > > > Can someone help me clear this up? > > > > Thanks > > > > Markus > > >
