| More docs on the ARB website. See also index of helppages. Last update on 24. Jun 2017 .

Main topics:

- ARB: a Short Introduction
- Glossary
- Starting ARB Parsimony
- K.L. Optimization of the Tree
- Nearest Neighbour Interchange and K.L. Optimization

Related topics:

# Nearest Neighbour Interchange

- OCCURRENCE
- DESCRIPTION
- NOTES
- EXAMPLES
- WARNINGS
- BUGS

## OCCURRENCE

### ARB_NT/Tree/Parsimony/<NNI>

## DESCRIPTION

### Searches for a better (more parsimonious) tree by swapping the relative positions of subtrees separated by not more than one edge.

## NOTES

### The current parsimony value (number of base changes needed) is displayed after the 'Current Par' prompt in the upper part of the 'ARB_PARSIMONY' window and the 'Message' window (pops up while calculating).

### On cycle of swapping is performed.

## EXAMPLES

### None

## WARNINGS

### None

## BUGS

### No bugs known