Wednesday, August 24, 2011
Bollinger Bands in Tableau
1. Start with a moving average - the industry standard appears to be "20 trailing periods".
2. Create a upper band from this average which is 2*STDEV(same periods) + moving average
3. Create a lower band which is moving average - 2*STDEV(same periods)
However, I have added Tableau Parameters because there are several variations on the Bollinger definition. E.G. instead of using a multiplier of "2" you can vary this, and instead of defining the moving average as "20 periods" can you can vary this. Download the book to review the calcs - it's remarkably simple, thanks to Table Calcs. Enjoy!