We have explored Bollinger Bands implementation in my previous post. In this article, we will explore deeper on implementing advanced features such as multi-conditions and alerts on Bollinger Bands.
As we visualize the trend of data (e.g. stock price movements), won’t it be beneficial to have alerts in visualization if the price violates upper or lower control limits? That implementation is straightforward with a calculated field for condition and using a Mark Label on the chart as shown below
Going a step further, imagine that you want to have a dashboard that shows alerts based on combination of conditions from different sheets. Here the implementation gets tricky as Tableau by default is not designed for inter-chart interaction as each sheet generates visualizations based on its underlying data and data source.
One way of implementing is to use multiple data sources and link them in your chart. This is possible if you can link (join) data source of ChartA with that of ChartB with a common dimension. The resulting implementation can have scenarios like :
- Trigger condition in ChartA has been met
- Trigger condition in ChartB has been met
- In Chart C, check for its own Trigger condition, check for trigger in ChartA and ChartB display an Alert, which can be a strategy or aid a decision ( for example, in Stock Trading it can be a BUY/SELL/HOLD decision)
In real-lime, this can be extended further for advanced features to generate Dynamic Dashboards and email alerts. With analytics evolving smarter, you don’t want to view all data visualizations everyday and will be interested only in those visualizations where the triggers have been met.
The final implementation is below
I will update this post with source and implementation steps shortly.