Note: I am updating this post to include the following cross-link to Andy Kriebel's vizwiz.blogspot.com blog. He came up with a superior-looking approach to the banding effect. That post is here.
Just another calc that I have been meaning to pick off the list. The essence of the Bollinger Band is this: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!
3 comments:
This is great stuff, thank you for putting this together.
If you like this, I recommend Scott Burrill's presentation at the TCC2011 "Pushing the Limits: Big Data and the Path from Insight to Value" currently slotted for Wednesday morning.
I like this a lot, in fact. Beautiful. And I forgot that nice technique of displaying different chart types.
Super work Alan! Thanks for sharing this.
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