treefarm.ancestry_checker.common_ids(descendent_ids, ancestor_ids, threshold=0.5)[source]

Determine if at least a given fraction of ancestor’s member particles are in the descendent.

  • descendent_ids (list of ints) – Member ids for first halo.
  • ancestor_ids (list of int) – Member ids for second halo.
  • threshold (float, optional) – Critical fraction of ancestor’s particles ending up in the descendent to be considered a true ancestor. Default: 0.5.

Return type:

True or False