mql5/Indicators/MyIndicators/TDI_Pro.md

Trader's Dynamic Index (TDI) Professional

1. Summary (Introduction)

The Trader's Dynamic Index (TDI), developed by Dean Malone, is a comprehensive, "all-in-one" market analysis tool. It is a hybrid indicator that builds upon the Relative Strength Index (RSI), smoothing it with multiple moving averages and enveloping it in volatility bands to provide a simultaneous view of trend, momentum, and volatility.

Our TDI_Pro implementation is a unified, professional version that allows the underlying RSI calculation to be based on either standard or Heikin Ashi price data, selectable from a single input parameter.

2. Mathematical Foundations and Calculation Logic

The TDI is constructed in a layered, sequential process.

Required Components

• RSI Period: The lookback period for the base RSI.
• Price Line Period: The period for the first, fastest moving average.
• Signal Line Period: The period for the second, slower moving average.
• Base Line Period: The period for the third, slowest moving average.
• Bands Deviation: The standard deviation multiplier.
• Source Price: The price series for the initial RSI calculation.

Calculation Steps (Algorithm)

1. Calculate the Base RSI: First, a standard Wilder's RSI is calculated.
2. Calculate the RSI Price Line (Fast Line): The base RSI line is smoothed using a Simple Moving Average (SMA) with the Price Line Period (default 2).
   • \text{Price Line}_t = \text{SMA}(\text{RSI}, 2)_t
3. Calculate the Trade Signal Line (Slow Line): The Price Line is smoothed again using an SMA with the Signal Line Period (default 7).
   • \text{Signal Line}_t = \text{SMA}(\text{Price Line}, 7)_t
4. Calculate the Market Base Line (Trend Line): The Price Line is smoothed a third time, using a Base Line Period SMA (default 34).
   • \text{Base Line}_t = \text{SMA}(\text{Price Line}, 34)_t
5. Calculate the Volatility Bands: Bollinger Bands are calculated around the Base Line. The standard deviation is calculated on the base RSI, using the Base Line Period.
   • \text{StdDev}_t = \text{StandardDeviation}(\text{RSI}, \text{Base Line Period})_t
   • \text{Upper Band}_t = \text{Base Line}_t + (\text{Bands Deviation} \times \text{StdDev}_t)
   • \text{Lower Band}_t = \text{Base Line}_t - (\text{Bands Deviation} \times \text{StdDev}_t)

3. MQL5 Implementation Details

Our MQL5 implementation is a robust, definition-true representation of the TDI, built with a modular and stable architecture.

• Component-Based Design: The TDI calculator (TDI_Calculator.mqh) reuses our existing, standalone RSI_Pro_Calculator.mqh module. This eliminates code duplication and ensures that the base RSI is always our robust, definition-true Wilder's RSI.

• Object-Oriented Logic:

  • The CTDICalculator base class contains a pointer to an CRSIProCalculator object.
  • The Heikin Ashi version (CTDICalculator_HA) is achieved simply by instructing the main calculator to instantiate the Heikin Ashi version of the RSI module (CRSIProCalculator_HA).

• Stability via Full Recalculation: The TDI's calculation is highly state-dependent. To ensure perfect accuracy, our implementation employs a "brute-force" full recalculation on every tick.

4. Parameters

• RSI Period (InpRsiPeriod): The lookback period for the base RSI. Default is 13.
• Price Line Period (InpPriceLinePeriod): The smoothing period for the fast (green) line. Default is 2.
• Signal Line Period (InpSignalLinePeriod): The smoothing period for the slow (red) signal line. Default is 7.
• Base Line Period (InpBaseLinePeriod): The smoothing period for the yellow trend line and the volatility bands. Default is 34.
• Bands Deviation (InpBandsDeviation): The standard deviation multiplier for the blue volatility bands. The standard value is 1.618.
• Source Price (InpSourcePrice): The price data for the base RSI calculation. This unified dropdown allows you to select from all standard and Heikin Ashi price types.

5. Usage and Interpretation

• Trend Direction (Market Base Line - Yellow): The yellow line indicates the overall medium-term trend.
• Momentum (Price Line - Green): The green line shows the short-term momentum.
• Entry Signals (Green/Red Crossover): The primary entry signal is the crossover of the green Price Line and the red Signal Line.
• Volatility (Volatility Bands - Blue): When the bands tighten (squeeze), it indicates low volatility. When they widen, it confirms a strong move is underway.
• Caution: The TDI is most effective when its signals are confirmed by price action and analysis of the market structure on the main chart.