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# treeplot

Plot picture of tree

## Syntax

treeplot(p)
treeplot(p,nodeSpec,edgeSpec)

## Description

treeplot(p) plots a picture of a tree given a vector of parent pointers, with p(i) = 0 for a root.

treeplot(p,nodeSpec,edgeSpec) allows optional parameters nodeSpec and edgeSpec to set the node or edge color, marker, and linestyle. Use '' to omit one or both.

## Examples

To plot a tree with 12 nodes, call treeplot with a 12-element input vector. The index of each element in the vector is shown adjacent to each node in the figure below. (These indices are shown only for the point of illustrating the example; they are not part of the treeplot output.)

To generate this plot, set the value of each element in the nodes vector to the index of its parent, (setting the parent of the root node to zero).

The node marked 1 in the figure is represented by nodes(1) in the input vector, and because this is the root node which has a parent of zero, you set its value to zero:

`nodes(1) = 0;     % Root node`

nodes(2) and nodes(8) are children of nodes(1), so set these elements of the input vector to 1:

`nodes(2) = 1;     nodes(8) = 1;`

nodes(5:7) are children of nodes(4), so set these elements to 4:

`nodes(5) = 4;     nodes(6) = 4;     nodes(7) = 4;`

Continue in this manner until each element of the vector identifies its parent. For the plot shown above, the nodes vector now looks like this:

`nodes = [0 1 2 2 4 4 4 1 8 8 10 10];`

Now call treeplot to generate the plot:

`treeplot(nodes)`