| More docs on the ARB website. See also index of helppages. Last update on 22. May 2026 .

Main topics: ARB: a Short Introduction Glossary NTREE MODES (general info) | Related topics:
# SET ROOT MODE OCCURRENCE DESCRIPTION NOTES EXAMPLES WARNINGS BUGS ## OCCURRENCE
### ARB_NT and ARB_PARSIMONY: <S.ROOT> button in the left column ### F8 on keyboard
## DESCRIPTION
### The 'SET ROOT MODE' allows to position the root of the displayed tree to any of the edges. ### Click on the <S.ROOT> button to activate the 'SET ROOT MODE'. ### Set the root: Move the cursor to any position along the desired edge and click on the left mouse button. ### Use the right mouse button to search an optimal root, minimizing the distance to the farthest leaf on each side of the root.
## NOTES
### Short descriptions of the 'MODE' and the functions assigned to the mouse buttons are given in the fourth line of the 'ARB_NT' window. ### The root is always placed to the middle of the edge.
## EXAMPLES
### None
## WARNINGS
### None
## BUGS
### No bugs known