# Ultimate Oscillator (UO) Professional

## 1. Summary (Introduction)

The Ultimate Oscillator (UO), developed by Larry Williams, is a momentum oscillator designed to address the problem of false divergence signals by incorporating three different timeframes into a single, weighted oscillator value. This multi-timeframe approach provides a smoother and more reliable measure of momentum.

Our `UltimateOscillator_Pro` implementation is a unified, professional version that includes an **optional, fully customizable signal line** and allows the calculation to be based on either **standard** or **Heikin Ashi** price data.

## 2. Mathematical Foundations and Calculation Logic

The UO's calculation combines buying pressure over three distinct periods.

### Required Components

- **Three Periods (N1, N2, N3):** The three lookback periods (e.g., 7, 14, 28).
- **Price Data:** The `High`, `Low`, and `Close` of each bar.

### Calculation Steps (Algorithm)

1. **Calculate Buying Pressure (BP):** $\text{BP}_i = \text{Close}_i - \text{Min}(\text{Low}_i, \text{Close}_{i-1})$
2. **Calculate True Range (TR):** $\text{TR}_i = \text{Max}(\text{High}_i, \text{Close}_{i-1}) - \text{Min}(\text{Low}_i, \text{Close}_{i-1})$
3. **Sum BP and TR over Three Periods.**
4. **Calculate Three Averages:** For each period, divide the sum of BP by the sum of TR.
5. **Calculate the Final UO:** Combine the three averages using a weighted formula (4, 2, 1) and scale the result to 100.
    $\text{UO}_i = 100 \times \frac{(4 \times \text{Avg}_7) + (2 \times \text{Avg}_{14}) + (1 \times \text{Avg}_{28})}{7}$

## 3. MQL5 Implementation Details

Our MQL5 implementation follows a modern, object-oriented design to ensure stability, reusability, and maintainability.

- **Modular Calculation Engine (`UltimateOscillator_Calculator.mqh`):**
    The entire calculation logic is encapsulated within a reusable include file.
  - **`CUltimateOscillatorCalculator`**: The base class that performs the full UO and signal line calculation.
  - **`CUltimateOscillatorCalculator_HA`**: A child class that inherits all logic and only overrides the data preparation step to use smoothed Heikin Ashi prices.

- **Optional Signal Line:** The indicator is enhanced with a user-configurable moving average signal line, with all MA types calculated manually for robustness. A `Display Mode` input allows the user to toggle the visibility of this line.

- **Stability via Full Recalculation:** We employ a "brute-force" full recalculation within `OnCalculate` for maximum stability.

- **Efficient Calculation:** The summation of Buying Pressure and True Range is handled by an efficient **sliding window sum** technique.

## 4. Parameters

- **Period 1, 2, 3 (`InpPeriod1`, `InpPeriod2`, `InpPeriod3`):** The three lookback periods for the oscillator. Defaults are `7`, `14`, `28`.
- **Candle Source (`InpCandleSource`):** Allows the user to select the candle type for the calculation (`Standard` or `Heikin Ashi`).
- **Signal Line Settings:**
  - `InpDisplayMode`: Toggles the visibility of the signal line.
  - `InpSignalPeriod`: The lookback period for the signal line.
  - `InpSignalMAType`: The type of moving average for the signal line.

## 5. Usage and Interpretation

The Ultimate Oscillator is primarily used to identify divergences, which are its most reliable signals.

- **Bullish Divergence (Primary Buy Signal):**
    1. The price makes a **lower low**, but the UO makes a **higher low**.
    2. The low of the UO during the divergence should be **below 30**.
    3. A buy signal is triggered when the UO subsequently breaks **above the high** it made during the divergence.
- **Bearish Divergence (Primary Sell Signal):**
    1. The price makes a **higher high**, but the UO makes a **lower high**.
    2. The high of the UO during the divergence should be **above 70**.
    3. A sell signal is triggered when the UO subsequently breaks **below the low** it made during the divergence.
- **Signal Line Crossovers:** If the signal line is enabled, its crossovers with the UO line can provide earlier, shorter-term momentum signals, similar to a MACD or Stochastic.
- **Caution:** Larry Williams specifically designed the indicator for its divergence signals. Simple overbought/oversold readings or signal line crossovers should be used with more caution.