Aggregators: when item ranking matters

  • 22 December 2021
  • 0 replies
  • 790 views

Userlevel 2
Badge +3

 

In Pigment, every Dimension List is ordered. The default order of a list is the creation order of each Dimension List item. However, you can change this default order in the Dimension List setting. In the Special properties menu, there is a Ranking property field where you can select any unique properties as the ranking property. 

 

Click on the image to expand the view

 

This default ranking is used whenever order matters and especially when you perform an aggregation (using a By, Remove, or Select modifier) with an aggregator that uses the list order. 

For example, the first aggregator may return a different value if you change the ranking property because the list order has changed. 

'My Source Metric'[Remove first : 'Source Metric Dimension']

Please find below the list of aggregators where the ranking of a dimension impacts the result: 

Aggregator Description Available data types
First Returns the value of the first item from the aggregated dimension.

All

Firstnonblank Returns the value of the first non-blank item from the aggregated dimension. All
Firstnonzero Returns the value of the first item that is different from zero from the aggregated dimension. Number, Integer
Last Returns the value of the last item from the aggregated dimension. All
Lastnonblank Returns the value of the last non-blank item from the aggregated dimension. All
Lastnonzero Returns the value of the last item that is different from zero from the aggregated dimension. Number, Integer
Textlist Returns the list of aggregated text values, separated by a comma. Text

 

So, if you change the list ranking properties, aggregating data using the above aggregators will return different results. 

 

 

Example

 

Here is a country list : 

 

 

When no ranking property is defined, the first item is Italy

 

 

When we use the Order property as the ranking property, the first item is France.

 

 

However, you can also choose any unique property to perform your ordered aggregation, not necessarily the one defined in the Metric's settings! To do this, use the on operator. 

 

 

And you can even use the ranking property of one of your Dimension's properties! 

 

 

 


0 replies

Be the first to reply!

Reply