[jav] HeikinAshized Oscillators

This script allows to HeikinAshize different commonly used centered oscillators.
It plots them like Heikin Ashi candles. In this way, we can eliminate some of the noise and uncertainty that is inherent to applying only one calculation period to the oscillators.
Applying Heikin Ashi to an oscillator might be advantageous compared to applying it directly to the chart, because you are not altering price readings. The obvious advantage is the clear visualization of the trend directions without noise.

INPUTS
The oscillators included are:

• Relative Strength Index (RSI)
  
• Stochastic
  
• Stochastic RSI
  
• Fisher transform
  
• Inverse Fisher Transform of RSI (IFTRSI)
  
• Commodity Channel Index (CCI)
  
• Money Flow Index (MFI)
  
• Chande Momentum Oscillator (CMO)
  
• Momentum (MOM)
  
• True Strength Index (TSI)
  
• Williams' Percent Range (WPR).
  

Apart from the choice of one of these indicators, only two more inputs are required:

• the main (median) period and
  
• the % of variability of this period.
  

RESULTS
The script calculates 4 evenly spaced periods from that data (period and variability), e.g. for a period of 50 and a variability of 30%, the script calculates oscillator values for 4 different periods evenly spaced around 50, (35, 45, 55, 65) and uses these 4 values to draw the Heikin Ashi candle.

The script also plots the usual upper/lower (overbought/oversold) values, as well as the central line.

CREDITS
The interesting concept of applying Heikin Ashi to an oscillator was recently introduced in Tradingview by @JayRogers . Many thanks for the idea.
For Heikin Ashi calculations, the useful script by @allanster was taken as a reference.
Any improvements, modifications or suggestions are welcome.