Variable Moving Average Bands [LazyBear]

VMA Bands are ATR bands with VMA as its centre. For a description of options, refer to my VMA post: tradingview.com/v/6Ix0E5Yr/.

I have moved VMA calculation in to a separate function. Feel free to use calc_vma() in your scripts. For more MA calculation function (KAMA, VIDYA and others), refer to my complete list of indicators below.

Wish you all a very prosperous New year. Hope these indicators make you all more money this year too :)

List of my other indicators:
- GDoc: docs.google.com/document/d/15AGCufJZ8CIUvwFJ9W-IKns88gkWOKBCvByMEvm5MLo/edit?usp=sharing
- Chart: tradingview.com/v/4IneGo8h/