There is an example of radar chart on OSIsoft's GitHub.
PI-Vision-Custom-Symbols/Community Samples/OSIsoft/amcharts-radar at master · osisoft/PI-Vision-Custom-Symbols · GitHub
This example can show 1 tag/attribute's time series data as a spider chart.
On the other hand, there are some cases that we want to show multiple item's snapshot values as a radar chart.
I changed this sample code and now this symbol can show multiple item's snapshot values.
Code is in my github account.
It works by PI Vision 2017/ PI Vision 2017 R2.
Enjoy multi items radar chart.