In ArcGIS there is a tool called "Hot Spot Analysis (Getis-Ord Gi)" under Spatial Statistics Tools > Mapping Clusters
I am wondering if it is possible to replicate this in FME ? The example I have concerns "delay minutes" based on incidents on the UK rail system, so it is the "Delay_Minutes" value I wish to be evaluated.
This article describes an FME custom transformer for Cluster or Density Modelling. But FME doesn't have a Hot Spot Analysis (Getis-Ord Gi) algorithm. However, you might consider using the RCaller to use one of that R packages that includes Getis-Ord Gi such as the spdep package. There's a bit more on using R with FME and also in this blog article from Mark Ireland.