How to create a Radar Chart (Spider Chart) in Spotfire

Radar Chart (also known as Spider Chart) aren’t natively supported in Spotfire.
Here’s a way of creating a fully functionnal Radar Chart using a Scatter Plot and some basic mathematics in Spotfire.

This tutorial will use R’s Motor Trend Car Road Tests dataset (info and csv). The main Idea is to use the Polar coordinate system (note : a radar chart is also known as a polar chart) in order to represent each point

We will have to unpivot the dataset and calculate an angle (Val r) and a radius (Cat θ) :

  • Val r : [Value] / Max([Value]) OVER ([Category])
  • Cat θ : Rank([Category]) / Max(Rank([Category])) * 2 * PI()

This allows us to create an x-axis and an y-axis using trigonometry :

  • rad_x : [Val r] * cos([Cat θ])
  • rad_y : [Val r] * sin([Cat θ])

Then, you can use the « Lines&Curves » chart option to trace a line between each point :

As usual, the Spotfire Analysis is available as a dxp file here : Spotfire Radar Chart / Spider Chart Example.dxp

 

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