ka66: Externally-Sourced MACD

This indicator generalises the idea of MACD to take any arbitrary series available on the chart, using input.source values.

To provide an overview of the MACD indicator:

• You have two EMAs, one with a faster period, usually 12, another with a slower period, usually 26.
  
• You calculate a MACD line, by doing (fastEMA - slowEMA)
  
• You then calculate a Signal Line by taking a moving average of the MACD line over some period.
  

With this indicator, you can analyse momentum between any 2 series (not just EMAs), they could be raw close prices, other moving averages on the chart including specialised ones, that most MACD implementations won't provide a facility for, for example Kaufman Moving Average.

The chart shows this indicator sourcing 2 inputs from the chart:

1. A Hull Moving Average as the fast series
   
2. And a Simple Moving Average as the slow series
   

It then calculates the MACD (Series1 - Series2), and a Signal line from the resulting MACD.

A signal series is still calculated manually by the indicator, and thus will be restricted to the provided moving average options (this indicator provides a few like EMA, SMA, Hull, and so on).

Uses of this indicator are essentially what you will use a MACD for:

1. Evaluate momentum of a strength.
   
2. Crossover Signals: MACD vs. Signal, MACD vs. Zero Line, MACD Histogram gradation.
   
3. Evaluate overbought/oversold conditions.
   
4. As a low-resolution view to confirm price action.
   
5. Divergences