leaves

Determine terminal nodes

Syntax

N = leaves(T)

[N,K] = leaves(T,"sort")

N = leaves(T,"dp")

[N,K] = leaves(T,"sortdp")

Description

N = leaves(T) returns the indices of the terminal nodes of the tree T in the column vector N. The nodes are ordered from left to right as in the tree.

[N,K] = leaves(T,"sort") returns the sorted indices of the terminal nodes of the tree T. M = N(K) are the indices reordered as in the tree, from left to right.

[N,K] = leaves(T,"sort") and [N,K] = leaves(T,"s") are equivalent.

N = leaves(T,"dp") returns the depths and positions of the terminal nodes. N(i,1) is the depth and N(i,2) is the position of the ith terminal node.

[N,K] = leaves(T,"sortdp") returns the depths and positions of the sorted terminal nodes.

[N,K] = leaves(T,"sortdp") and [N,K] = leaves(T,"sdp") are equivalent.

Examples

Use leaves to Obtain Sorted Terminal Nodes

Create a binary tree of depth 3.

ord = 2;
t = ntree(ord,3);

Merge the nodes at indices 4 and 5. Plot the result.

t = nodejoin(t,5);
t = nodejoin(t,4);
fig = plot(t);

Programmatically, in Node Label, change the selected item from Depth_Position to Index.

plot(t,"setNodeLabel",fig,"Index")

List the indices of the terminal nodes.

tnodes_ind = leaves(t)

tnodes_ind = 6×1

     7
     8
     4
     5
    13
    14

List the terminal nodes, this time sorted on the index.

[tnodes_ind,Ind] = leaves(t,"sort")

tnodes_ind = 6×1

     4
     5
     7
     8
    13
    14

Ind = 6×1

     3
     4
     1
     2
     5
     6

List the depths and positions of the terminal nodes.

tnodes_depo = leaves(t,"dp")

tnodes_depo = 6×2

     3     0
     3     1
     2     1
     2     2
     3     6
     3     7

List the depths and positions again, this time, sorted on depth and position.

[tnodes_depo,Ind] = leaves(t,"sortdp")

tnodes_depo = 6×2

     2     1
     2     2
     3     0
     3     1
     3     6
     3     7

Ind = 6×1

     3
     4
     1
     2
     5
     6

Input Arguments

T — Tree

ntree object | dtree object | wptree object

Tree, specified as a ntree, dtree, or wptree object.

Output Arguments

N — Terminal node description

vector | matrix

Terminal node description, returned as a column vector or matrix. The nodes are numbered from left to right as in the tree T. The root index is 0.

• If N = leaves(T), N is a P-by-1 column vector, where P is the number of terminal nodes in the tree. N(i) is the index of the ith node.

• If N = leaves(T,"dp"), N is a P-by-2 matrix. N(i,1) is the depth and N(i,2) is the position of the ith node.

K — Indices

vector

Indices, returned as a vector. The indices K are such that M = N(K) are the terminal indices reordered from left to right.

Version History

Introduced before R2006a