Amibroker Afl | Code Verified
: Set breakpoints to pause execution and hover over variables to see their current values.
| Pitfall | Why It’s Problematic | How to Avoid | | :--- | :--- | :--- | | | Positive arguments reference future bars, introducing look‑ahead bias and invalid backtest results. | Always use a negative argument to refer to past data. | | Array arguments in if statements | if requires a single scalar value. Passing an array is syntactically allowed but logically ambiguous and will not work as expected. | Use LastValue(array) or reference a specific index ( array[index] ) to get a scalar. | | Hard‑coded bar counts in loops | The code will crash with Error 10 if a symbol has fewer bars than the hard‑coded limit. | Loop from 0 to BarCount-1 , or check if(BarCount > 300) first. | | Misusing IIf() for strings | IIf() returns an array, not a string. Using it for text generation will produce unexpected results. | Use WriteIf() for conditional string outputs. | | Forgetting that parameters are not automatically reset | When pasting a new strategy over an existing one, old parameter values can persist and corrupt your test. | Click the "Reset all" button in the Parameters dialog before running a new backtest. | | Using Notepad or external editors | Saving code with Notepad may inadvertently change the file extension to .txt , and external editors may not save changes automatically before a backtest. | Always use the built‑in AFL Editor; the Analysis window automatically saves the current file when you run a scan or backtest. | | Assuming prices are never zero | Writing C == 0 as a signal will never trigger for stocks, rendering your strategy inactive. | Use explicit False or 0 if you want a condition that never fires. |
The and Official Community Forum are the primary sources of verified information. The forum is frequented by experienced users and the software’s creator, Tomasz Janeczko, who often provides definitive answers on AFL semantics and best practices.
The first step to a verified code is ensuring the Amibroker engine can read it. amibroker afl code verified
Once your AFL code has passed basic and intermediate checks, advanced verification steps can further ensure reliability and performance.
must include a settings header or instructions:
Uses Plot and PlotShapes to verify the signals visually. : Set breakpoints to pause execution and hover
The final stage of verification is connecting your clean logic to an execution environment.
If you are looking to audit your script further, could you share the you are using, your intended execution timeframe , or the specific error codes you are seeing? Knowing these details will help pinpoint the exact updates needed to get your AFL strategy verified.
Optimized code prevents delayed trade entries. | | Array arguments in if statements |
AmiBroker Formula Language (AFL) is a highly efficient, array-based language designed for fast backtesting and real-time charting. However, its high speed comes with a challenge. AFL handles data arrays differently than procedural languages like C++ or Python. Writing unverified code can lead to common errors, such as look-ahead bias or syntax problems, which can drain your trading account.
By following this guide, your AFL code will be both syntactically (it runs) and logically (it does what you think it does).
: Use Plot() or PlotShapes() to draw conditions on the chart, confirming that buy/sell arrows appear exactly where you expect them. ⚠️ Important Considerations
Once your code compiles without syntax errors, run these three audits to fully verify its performance: The Empty Data Test
