Friday, August 26, 2011

Colour Decour

Wrapping up the week with a light-hearted example - ever want to change the color scheme on the fly? nested CASE statements can get you there, along with some spaces... lots and lots of spaces padding your display values... kind of hacky but hey, who I am to complain ... :)

Thursday, August 25, 2011

MACD Technical Analysis with Tableau

Moving Average Convergence Divergence (MACD)

As a follow up to my previous post on Bollinger Bands, I took a stab at MACD, which derives from similar calculations.

This is a somewhat squirrely subject and I might be opening myself up to attack or a can of worms in this attempted analysis. As a preemptive strike against such attacks, let me start off by saying that as a stock trader, I fall firmly in the "fundamentals" camp, and this type of technical analysis does little for me. Second, allow me to graciously further admit that my math could very well be wrong. Finally, grant me the chance to comment on the fact that we can find on the internet dozens and dozens of permutations on the mathematics of this MACD subject.

Three web links which I found quite helpful in understanding the math behind MACD are these:

The Wikipedia Page on MACD
The Wikipedia Page on Moving Averages and Exponential Moving Averages
which are required components of MACD analysis, and lastly,
A Stock Charts Dot Com web page which has a nice discussion on the subject.

Feedback on the mathematics is welcome.

Wednesday, August 24, 2011

Bollinger Bands in Tableau

Note: I am updating this post to include the following cross-link to Andy Kriebel's 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!

Friday, August 19, 2011


This is a variation based upon highly original work done by Andy Cotgreave. Thanks, Andy! You're the best!

Thursday, August 4, 2011

What's New in 6.1

A quick post for "what's new in 6.1" specific to mapping: Dark Maps, Built-in Geocoding for Cities worldwide, and cartographic labels in French and German. These are three great features that make the mapping sizzle even more than before!

For the full list of 6.1 features, see the release page

Dark Maps

Geocoding for Worldwide Cities

Cartography Labels in German and French