On day two of Dashboard-week at The Data School (DS8) we were given data on the southern oscillating index (SOI) for every month since 1950. The SOI describes the atmospheric processes that occur above the Pacific Ocean. It quickly became evident that the SOI is only one of two factors that contribute to the occurrence El Niño or La Niña. The other factor is the Sea Surface Temperature (SST) of the Pacific Ocean. The El Niño or La Niña weather phenomena are two opposite phases of the El Niño-Southern Oscillation (ENSO) cycle. I wanted to create a dashboard in which it was possible to clearly distinguish between the two different weather phenomena without being repetitive and display the data on a single dashboard without scrolling.
I chose to apply a parameter dependent filter to the dashboard which enables a user to select the information only relevant to what he/she selected by replacing specific parts of the dashboard. In this blog I’ll explain how this is done.
Create your sheets and dashboard
As the parameter can be seen as a smart dashboard action, it is firstly necessary to build all the sheets you will want to display on the dashboard – even those that you are hiding initially. The sheets you intend to show or hide using the parameter all need to be in the same container and their titles removed. Initially they will be very tightly spaced and not necessarily look very pretty, but the size of the container will be the size of the sheet being displayed. Once the filter is applied, the selected sheet will take up the space in the container while the other will disappear.
Creating the parameter
Once your very squished dashboard has been built, return to one of your sheets to create a parameter with a descriptive name, with a string as data type and create a list of values (the list depending on the number of sheets you want to exchange with the parameter). I personally use numbers when referring to the variables because numbers can’t be misspelled. Click OK.
Create a calculated field which links the parameter to your data. Give it a descriptive name and drag or type the name of your new parameter into the calculation window and click OK.
Drag the created field to the filter card. Under the General Tab, select the ‘Custom Value List’ and type in the number of the parameter option you want show and click on the plus on the right side of the box to add it to the view. In my example, I listed El Niño as 2, while La Niña was listed as 3 in my parameter. For all the sheets representing El Niño information this filter is applied.
The same process is repeated for the sheets representing the La Niña information, except in this case the custom value list contains ‘3’ to represent all La Niña data.
Displaying your parameter
Under the parameters section of any of your sheets you will be able to see your created parameter. Right click on it and choose ‘Show Parameter Control’ to the sheets you would like the parameter to apply. It is possible to test if the filter works correctly as the sheet will disappear when it’s option is not selected on the parameter.
In summary
The technique is ideal when dashboard space is limited. It is important to note that each time the parameter is changed, a filter needs to change, and a new sheet needs to be loaded which may also take a time and additional processing power. Apart from potential slow loading times when changing the parameter, the technique is very useful for communicating data.
