API Reference

Working with Merger-Trees

The load can load all supported merger-tree formats. Once loaded, the save_arbor and save_tree functions can be used to save the entire arbor or individual trees.

load(filename[, method]) Load an Arbor, determine the type automatically.
Arbor(filename) Base class for all Arbor classes.
save_arbor([filename, fields, trees, …]) Save the arbor to a file.
save_tree([filename, fields]) Save the tree to a file.
set_selector(selector, *args, **kwargs) Sets the tree node selector to be used.
TreeNodeSelector(function[, args, kwargs]) The TreeNodeSelector is responsible for choosing which one of a halo’s ancestors to return when querying the line of main progenitors for a halo.
add_tree_node_selector(name, function) Add a TreeNodeSelector to the registry of known selectors, so they can be chosen with set_selector.
max_field_value(ancestors, field) Return the TreeNode with the maximum value of the given field.
min_field_value(ancestors, field) Return the TreeNode with the minimum value of the given field.

Making Merger-Trees

TreeFarm(time_series[, setup_function]) TreeFarm is the merger-tree creator for Gadget FoF and Subfind halo catalogs.
trace_ancestors(halo_type, root_ids[, …]) Trace the ancestry of a given set of halos.
trace_descendents(halo_type[, fields, filename]) Trace the descendents of all halos.
set_selector(selector, *args, **kwargs) Set the method for selecting candidate halos for tracing halo ancestry.
set_ancestry_checker(ancestry_checker, …) Set the method for determing if a halo is the ancestor of another halo.
set_ancestry_filter(ancestry_filter, *args, …) Select a method for determining which ancestors are kept.
set_ancestry_short(ancestry_short, *args, …) Select a method for cutting short the ancestry search.
AncestryChecker(function[, args, kwargs]) An AncestryCheck is a function that is responsible for determining whether one halo is an ancestor of another.
add_ancestry_checker(name, function) Add an ancestry checking function to the registry.
common_ids(descendent_ids, ancestor_ids[, …]) Determine if at least a given fraction of ancestor’s member particles are in the descendent.
AncestryFilter(function[, args, kwargs]) An AncestryFilter takes a halo and a list of ancestors and returns a filtered list of filtered list of ancestors.
add_ancestry_filter(name, function) Add an ancestry filter function to the registry.
most_massive(halo, ancestors) Return only the most massive ancestor.
AncestryShort(function[, args, kwargs]) An AncestryShort takes a halo and an ancestor halo and determines if the ancestry search should come to an end.
add_ancestry_short(name, function) Add an ancestry short-out function to the registry.
above_mass_fraction(halo, ancestor, fraction) Return only the most massive ancestor.
HaloSelector(function[, args, kwargs]) A HaloSelector is a function that is responsible for creating a list of ids of halos that are potentially ancestors of a given halo.
add_halo_selector(name, function) Add a HaloSelector to the registry of known selectors, so they can be chosen with set_selector.
sphere_selector(hc, ds2, radius_field[, …]) Select halos within a sphere around the target halo.
all_selector(hc, ds2) Return all halos from the ancestor dataset.

Internal Classes

Arbor(filename) Base class for all Arbor classes.
CatalogArbor(filename) Base class for Arbors created from a series of halo catalog files where the descendent ID for each halo has been pre-determined.
FieldInfoContainer(arbor) A container for information about fields.
FieldContainer(arbor) A container for field data.
FakeFieldContainer(arbor[, name]) A fake field data container used to calculate dependencies.
FieldIO(arbor) Base class for FieldIO classes.
TreeFieldIO(arbor) IO class for getting fields for a tree.
RootFieldIO(arbor) IO class for getting fields for the roots of all trees.
FallbackRootFieldIO(arbor) Class for getting root fields from arbors that have no specialized storage for root fields.
CatalogDataFile(filename, arbor) Base class for halo catalog files.
TreeNode(uid[, arbor, root]) Class for objects stored in Arbors.
TreeNodeSelector(function[, args, kwargs]) The TreeNodeSelector is responsible for choosing which one of a halo’s ancestors to return when querying the line of main progenitors for a halo.
ArborArbor(filename) Class for Arbors created with ytree version 1.1.0 or earlier.
ArborArborFieldInfo(arbor)
ArborArborTreeFieldIO(arbor)
ArborArborRootFieldIO(arbor)
ConsistentTreesArbor(filename) Arbors from consistent-trees output files.
ConsistentTreesFieldInfo(arbor)
ConsistentTreesTreeFieldIO(arbor)
RockstarArbor(filename) Class for Arbors created from Rockstar out_*.list files.
RockstarFieldInfo(arbor)
RockstarDataFile(filename, arbor)
TreeFarmArbor(filename) Class for Arbors created with TreeFarm.
TreeFarmFieldInfo(arbor)
TreeFarmDataFile(filename, arbor)
TreeFarmTreeFieldIO(arbor)
YTreeArbor(filename) Class for Arbors created from the save_arbor or save_tree functions.
YTreeTreeFieldIO(arbor)
YTreeRootFieldIO(arbor)