// --- DDE Output to Excel/Trading Bridge --- if (Buy) { fdde = DDEInitiate("Excel", "Sheet1"); DDEPoke(fdde, "R1C1", "BUY"); DDEPoke(fdde, "R1C2", Symbol()); DDEPoke(fdde, "R1C3", WriteVal(C)); DDETerminate(fdde); } Even experienced users write buggy code. Here is your AFL debugging toolkit. 6.1 The _TRACE() Function Prints values to the log window (View -> Log).
// --- Exploration for Equity Curve Analysis --- SetBarsRequired(500, 0); Equity = Foreign("~~~EQUITY", "C"); // Internal equity array MonthlyReturn = (Equity - Ref(Equity, -20)) / Ref(Equity, -20) * 100; Filter = 1; AddColumn(MonthlyReturn, "20-Period Return %", 2.2); AddColumn(Stdev(MonthlyReturn, 20), "Volatility", 2.2); Backtesting is where AFL truly shines. The default settings are good, but professional optimization requires custom metrics. 4.1 Custom Backtest Interface (CBI) You can override AmiBroker’s core logic using SetCustomBacktestProc .
Introduction: Why AFL is the Backbone of Quantitative Trading In the world of retail algorithmic trading, few platforms offer the perfect blend of power, speed, and customization like AmiBroker . For over two decades, professional traders and hobbyists alike have relied on AmiBroker for backtesting, scanning, and real-time trading. The secret sauce behind this dominance is AFL (AmiBroker Formula Language) . amibroker afl code
// --- Parameters --- Periods = Param("BB Periods", 20, 5, 50, 1); Width = Param("BB Width", 2.0, 1.0, 4.0, 0.1); ATRPeriod = Param("ATR Stop", 10, 5, 30, 1); // --- Calculations --- BBLower = BBandBot(C, Periods, Width); BBUpper = BBandTop(C, Periods, Width); TrendMA = MA(C, 200); ATR_Val = ATR(ATRPeriod);
Buy = C > MA(C, 20); // Buy when price above 20 MA Sell = C < MA(C, 20); // Sell when price below 20 MA When you run this in AmiBroker’s Analysis window, the software interprets the Buy array (1 for True, 0 for False) and executes trades. Let's move beyond the basics. Below is a complete Mean Reversion + Trend Filter system. The "Bollinger Band Bounce" Strategy This code buys when price touches the lower band in an uptrend. // --- DDE Output to Excel/Trading Bridge ---
if (Sell AND currentPos == 1) { currentPos = 0; StaticVarSet("MyPosition", 0); } Using AmiBroker’s DDE or COM interface , you can bridge to Interactive Brokers, Tradier, or a custom API.
// --- Alerts --- AlertIf(Buy, "", "Buy Signal", 1); AlertIf(Sell, "", "Sell Signal", 2); // --- Exploration for Equity Curve Analysis ---
// --- Plotting for Visualization --- Plot(C, "Price", colorBlack, styleCandle); Plot(BBLower, "Lower Band", colorGreen, styleDots); Plot(BBUpper, "Upper Band", colorRed, styleDots); Plot(TrendMA, "200 MA", colorBlue, styleLine);