ytree.tree_farm.tree_farm.TreeFarm.trace_ancestors¶
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TreeFarm.
trace_ancestors
(halo_type, root_ids, fields=None, filename=None)[source]¶ Trace the ancestry of a given set of halos.
A merger-tree for a specific set of halos will be created, starting with the last halo catalog and moving backward.
Parameters: - halo_type (string) – The type of halo, typically “FOF” for FoF groups or “Subfind” for subhalos.
- root_ids (integer or array of integers) – The halo IDs from the last halo catalog for the targeted halos.
- fields (optional, list of strings) – List of additional fields to be saved to halo catalogs.
- filename (optional, string) – Directory in which merger-tree catalogs will be saved.