trajCluster Behavior Changed After openair Update

[minair]

Bug description

I recently updated the openair package to version 2.18.2. My previous version was installed around 2021. After the update, I attempted to recreate charts using trajCluster and trajPlot with the same dataset. However, the resulting clusters are noticeably different.

As shown below, Cluster 4 (C4) remains consistent, but the other three clusters differ significantly. In fact, the clusters generated by the earlier version appear more accurate, as they accounted for both direction and trajectory angles.

Could you please look into this issue? It seems the clustering behavior may have changed in the newer version. Thank you!

• Clusters created with older version:
  

• Clusters created with current version:
  

Steps to reproduce

No response

Package version

No response

[jack-davison]

Hi @minair,

Thanks for flagging the change in trajCluster() behaviour.

@davidcarslaw - one for you. It appears that the code behind trajCluster() changed how Euclidean distances were being calculated in 74c0f77. I imagine the change was intended, but I'm not sure why it was made!

Jack