# istnode

Terminal nodes indices test

## Syntax

```R = istnode(T,N) ```

## Description

`istnode` is a tree-management utility.

`R = istnode(T,N)` returns ranks (in left to right terminal nodes ordering) for terminal nodes `N` belonging to the tree `T`, and 0's for others.

`N` can be a column vector containing the indices of nodes or a matrix that contains the depths and positions of nodes.

In the last case, `N(i,1)` is the depth of the `i`-th node and `N(i,2)` is the position of the `i`-th node.

The nodes are numbered from left to right and from top to bottom. The root index is 0.

## Examples

```% Create initial tree. ord = 2; t = ntree(ord,3); % binary tree of depth 3. t = nodejoin(t,5); t = nodejoin(t,4); plot(t) ``` ```% Change Node Label from Depth_Position to Inde % (see the `plot` function)x. ``` ```% Find terminal nodes and return indices for terminal % nodes in the tree. istnode(t,) ans = 6 istnode(t,) ans = 0 istnode(t,[1;7;14;25]) ans = 0 1 6 0 istnode(t,[1 0;3 1;4 5]) ans = 0 2 0 ```

## Version History

Introduced before R2006a