tree_sorting

Class and functions for building binary trees.

class Node(i)[source]

Bases: object

Class encapsulating a node in a binary tree.

Parameters:: i (any) – Value of this node.

value

Value of this node.

Type:: any

value_tuple

Tuple of the value of this node and the values of its children.

Type:: tuple

children

List of the children of this node.

Type:: List

leaves

List of the leaves of this node.

Type:: List

left

Left child of this node.

Type:: Node

right

Right child of this node.

Type:: Node

is_sorted

Whether the children of this node are sorted.

Type:: bool

parent

Parent of this node.

Type:: Node

tree_id

Identifier of the tree this node belongs to.

Type:: any

check_sorted(sort_depth=1)[source]

Check if the children of this node are sorted.

Parameters:: sort_depth (int) – Depth to check sorting at.
Returns:: is_sorted – Whether the children of this node are sorted.
Return type:: bool

flip_children()[source]: Flip children (left/right) of node.

get_current_value_tuple()[source]

Return current value tuple of this node.

Returns:: this_tup – Tuple of the value of this node and the values of its children.
Return type:: tuple

return_children_vals(depth=1)[source]

Return the values of the children of this node.

Parameters:: depth (int) – Depth up to which to return values.
Returns:: vals – Values of the children of this node.
Return type:: tuple

set_children(children, set_sorted=False, sort_depth=1)[source]

Set the children of this node.

Parameters:

children (List or tuple) – Children to be set.
set_sorted (bool) – If True, set the children in a sorted fashion.
sort_depth (int) – Depth to sort children at, if set_sorted is True.

update_children(set_sorted=False, sort_depth=1)[source]

Update the children of this node.

Essentially calls set_children with children already attached to node.

Parameters:

set_sorted (bool) – If True, set the children in a sorted fashion.
sort_depth (int) – Depth to sort children at, if set_sorted is True.

build_full_tree(l, L, L_R)[source]

Build a full binary tree from the given lists.

Works for rank 4, 5 and 6.

Parameters:

l (List) – list (multiset) of angular momentum indices l1,l2,…lN
L (List) – list (multiset) of intermediate angular momentum indices l1,l2,…lN
L_R (int) – Resultant angular momentum quantum number. This determines the equivariant character of the rank N descriptor after reduction. L_R=0 corresponds to a rotationally invariant feature, L_R=1 corresponds to a feature that transforms like a vector, L_R=2 a tensor, etc.

Returns:

root – Root node of the constructed tree.

Return type:

Node

build_quick_tree(l)[source]

Build a binary tree from the given list.

Rank is assumed to be the length of the list. If the rank is odd, a remainder is returned.

Parameters:: l (List) – List to build the tree from.
Returns:: tree – Tuple containing the tree and the remainder which could not fit in the tree.
Return type:: tuple