This code draws a custom indicator named "P/VF Boll" on the price chart with the following visual elements:
1. **Basis Line (Blue)**: This line represents the moving average value (ma_value) calculated based on the user-selected moving average type (SMA, EMA, or WMA) and length.
2. **Upper Bands (Green)**: The upper bands are calculated by adding a certain multiple of the standard deviation (dev1 to dev12) to the basis line. These bands represent a certain level of price volatility above the moving average.
3. **Lower Bands (Red)**: The lower bands are calculated by subtracting a certain multiple of the standard deviation (dev1 to dev12) from the basis line. These bands represent a certain level of price volatility below the moving average.
4. **Histogram (White and Gray)**: A histogram is drawn only when the average_price_change values are outside the 3rd standard deviation (dev3) and beyond. The histogram color alternates between white and gray, indicating higher price volatility.
The user can customize the following parameters:
- Average Length: The length of the moving average.
- Moving Average Type: The type of moving average to be used (SMA, EMA, or WMA).
- Timeframe: The timeframe used to calculate volume data.
- Deviation 1 to Deviation 12: Multipliers for calculating the upper and lower bands.
The purpose of this indicator is to visually represent the relationship between price volatility, volume, and the moving average, allowing traders to assess potential price breakouts or reversals when the price moves beyond certain levels of standard deviations from the moving average.