# ntree

NTREE constructor

## Syntax

```T = ntree(ORD,D) T = ntree T = ntree(2,0) T = ntree(ORD) T = ntree(ORD,0) T = ntree(ORD,D,S) T = ntree(ORD,D,S,U) ```

## Description

`T = ntree(ORD,D)` returns an NTREE object, which is a complete tree of order `ORD` and depth `D`.

`T = ntree` is equivalent to ```T = ntree(2,0)```.

`T = ntree(ORD)` is equivalent to ```T = ntree(ORD,0)```.

With `T = ntree(ORD,D,S)` you can set a “split scheme” for nodes. The split scheme field `S` is a logical array of size `ORD` by 1.

The root of the tree can be split and it has `ORD` children. You can split the `j`-th child if ```S(j) = 1```.

Each node that you can split has the same property as the root node.

With `T = ntree(ORD,D,S,U)` you can, in addition, set a userdata field.

Inputs can be given in another way:

`T = ntree('order',ORD,'depth',D,'spsch',S,'ud',U)`. For “missing” inputs the defaults are ```ORD = 2``` and `D = 0 , S = ones([1:ORD]) , U = {}`.

`[T,NB] = ntree( ... )` returns also the number of terminal nodes (leaves) of `T`.

For more information on object fields, type `help ntree/get`.

Class NTREE (Parent class: WTBO)

## Fields

 `wtbo` Parent object `order` Tree order `depth` Tree depth `spsch` Split scheme for nodes `tn` Column vector with terminal node indices

## Examples

```% Create binary tree (tree of order 2) of depth 3. t2 = ntree(2,3); % Plot tree t2. plot(t2) ``` ```% Create a quadtree (tree of order 4) of depth 2. t4 = ntree(4,2,[1 1 0 1]); % Plot tree t4. plot(t4) ``` ```% Split and merge some nodes using the gui % generated by plot (see the `plot` function). % The figure becomes: ``` ## Version History

Introduced before R2006a