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.
select_halos(criteria[, trees, select_from, …])	Select halos from the arbor based on a set of criteria given as a string.
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.
DefaultRootFieldIO(arbor)	Class for getting root fields from arbors that have no specialized storage for root fields.
DataFile(filename)	Base class for data files.
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.
AHFArbor(filename[, hubble_constant])	Arbor for Amiga Halo Finder data.
AHFFieldInfo(arbor)
AHFDataFile(filename, arbor)
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)
ConsistentTreesDataFile(filename)
ConsistentTreesTreeFieldIO(arbor)
LHaloTreeArbor(*args, **kwargs)	Arbors for LHaloTree data.
LHaloTreeFieldInfo(arbor)
LHaloTreeTreeFieldIO(arbor)
LHaloTreeRootFieldIO(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.
YTreeDataFile(filename)
YTreeTreeFieldIO(arbor)
YTreeRootFieldIO(arbor)